https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246449
I believe Internal`StringToDouble
was the only way to fast convert string into numbers.
Now in V12.3 it was removed: Internal`StringToDouble["1"]
asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 17 votes
answered by Itai Seggev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4848 20 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246400
I noticed in V 12.3, when trying to edit an expression in a cell, and moving/scrolling the mouse, the expression itself shakes. It seems to auto-resize or adjust while one is editing it. This does not ...
asked by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 14 votes
answered by MassDefect https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42264 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246507
Are you aware of any projects using the Wolfram language resp. Mathematica as an environment to explore the design of programming languages - in particular languages with a focus on mathematics (...
asked by Math Gaudium https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74255 12 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246444
I have a large codebase in which some functions make calls to Python TCP servers. The code used to work perfectly in Mathematica 12.2, but has not worked since I ...
asked by Shredderroy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9257 11 votes
answered by Dorian B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23275 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246520
I am trying to solve the heat equation on a circle with a square shaped hole in it. It works:
asked by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 9 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246476
The built in benchmark test on my stationary workstation shows an improvement from 2.82 to 5.99, all other hardware and operating systems settings the same. This looks very good. My question is: What ...
asked by FredrikD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1635 9 votes
answered by Dan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42162 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246466
After starting Mathematica 12.3, the default window size is like this, it’s too small for me, I dont want to manually drag the window every time. I have tried this,
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=15023
The basic multivariable Taylor expansion formula around a point is as follows:
\[ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac {1}{2!}(\mathbf a \cdot \nabla ) \]
asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 65 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 73 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34073
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 42 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 64 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6738
(Newbie question)
For every function I define I get this message: When I close and reopen Mathematica, and re-enter the function definition, I don’t get the message anymore. What does it mean?
asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 11 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4454
I’ve seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
asked by sblom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=178 124 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 86 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=78451
I want to plot the following function:
\[ \int \left (\frac {\Gamma (x+1)}{2}-\frac {\Gamma (x-1)}{2}\right ) \, dx \]
asked by Anixx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=651 4 votes
answered by k_v https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24727 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293
I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,
\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)
where \(U(x)\) is some potential and Ei is the ...
asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 49 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246395
Here’s some of my code. x1 results in returning the position of a list in a {{{n1}},{{n2}}...}
.
Im trying to flatten it such that the list reads out as {n1,n2,n3....}
some how it’s adding
elements.
asked by MT Cup https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79502 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246596
I have been trying to solve the following sine Gordon equation \(\partial _{x,x} u(x,t) - \partial _{t,t} u(x,t) - \sin (u(x,t)) - \alpha \partial _t u(x,t) + \gamma = 0\), for \(x \in [0,15]\) and
asked by t Lê Thành https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68852 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246560
Is it possible in Mathematica to get a step-by-step evaluation of some functions? Such that Mathematica is outputting not only the result but all the stages that have led to it? If so, how does one do ...
asked by putti.123 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80178 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246091
This code has been translated from the original Jos Stam code and improved with some Mathematica functions. It solves problem of viscous incompressible flow with electromagnetic force in a rectangle ...
asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 14 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246171
I want to create the following animation with Mathematica.
What is the simplest way to do so? My first effort:
asked by Kim Jong Un https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 12 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246088
Mathematica 12 on wolfram cloud isn’t rendering the table for an association of lists. According to the documentation you should be able to make columns in the table by:
However I tried this
asked by Ion Sme https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62529 10 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246309
The following code creates the Yin Yang symbol
asked by nilo de roock https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=156 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245994
Writing:
pts = {{1, 0}, {2, 0}, {2, 3}, {3, 3}, {3, 4}, {0, 4}, {0, 3}, {1, 3}, {1, 0}}; Graphics[{Red, Point[pts], Blue, Line[pts]}]
we get:
and all of this ...
asked by Rolex https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80016 9 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246125
I have this data data = Table[{x, Sin[5 x], Tanh[3 x]}, {x, -1, 1, 0.01}];
which I plot as follows
asked by valar morghulis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26937 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246046
I’d like a thick Line to look like ChartElementFunction -> "GlassRectangle"
How can
that be accomplished?
asked by Gannicus https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80033 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184
I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...
asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306
I have a complex expression with real positive variables only.
Mathematica Input Style:
asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 34 votes
answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 54 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1542
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
asked by Matthew Leingang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=395 109 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937
Salacious title, but true story.
asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes
answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting ...
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 18 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 30 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378
I’m visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something ...
asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 45 votes
answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506
I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246242 Is there a way to speed this function?
asked by An old man in the sea. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11313 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246300
I’m trying to integrate an ellipse: (x^2)/alpha^2) + ((y^2)/beta^2) = 1
. I am not sure if
I should have insert constants for alpha and beta or if there’s a way to keep them
there.
This is my code
asked by user80088 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80088 1 vote
answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=246152
ArrayQ provides a nice way to check for missing data (specifically, it checks if the array is ragged). But if you import your data as a dataset, and apply ArrayQ, it will return False for both ragged ...
asked by theorist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45215 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245937
To give some context, this problem is related to music theory. I have a matrix I’m generating with this code:
asked by Eriek https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18649 6 votes
answered by thorimur https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63584 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245908
Say, I have the following expressions
f = R[p] g = S[p]
where R,S are rational functions, and I want to find a polynomial such that
asked by nilo de roock https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=156 6 votes
answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245797
For dynamic system: \(\dot {x}=\frac {df}{dx}+u\) where \(f=e^{-x^2}\) It is necessary to develop optimal control, minimizing criterion: \(J= \int _{0}^{t_f} ((\frac {df}{dx})^2+u^2) \,dt \) Algorithm:
We ...
asked by dtn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67019 6 votes
answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245721
I have an association where the keys are the days of the week:
asked by theorist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45215 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245800
I am interested in exploiting a symbol that is similar to the PowerPoint’s laser pointer in the role of PlotMarkers. Is there any idea to create that!? This symbol ...
asked by Inzo Babaria https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=33967 5 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245782
Hyperreals are an extension to the real numbers; they formalise the concepts of infinities and infinitestimals as numbers, rather than the named limit points outside of the system of reals and form ...
asked by Julian Moore https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12858 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245784
Consider an association which contains a key which must not be prematurely evaluated.
assoc = <| key :> value |>
For example, a value of ...
asked by Anti Earth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=32591 5 votes
answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=627
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 152 votes
answered by ArgentoSapiens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=92 152 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336
I am wondering how to implement the multi-peak detecting and fitting in Mathematica.
Following is an example of fitting the data using three peaks (such that the
data ~ peak1 + peak2 + peak3
). The ...
asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 55 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 55 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108
I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?
If not, is there a way ...
asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035
Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?
asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 43 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 48 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736
I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems
I would ...
asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 130 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668
If you enter the following into Wolfram | Alpha, you get nice graphs:
graph 4 x^4 + y^2 = 2
How do you do this in Mathmatica? I realize that these are not ...
asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 40 votes
answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 41 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506
I am wondering what is the correct function in Mathematica to plot the true impulse
function, better known as the DiracDelta[]
function. When using this inside of a
...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245826
I’ve got an ODE system, which I attempt to solve by two ways: solving the system itself, and using vector ODE. Here is code of first way:
asked by Cpp Nosavvier https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79893 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245884
Consider the following integral: \[ I = \frac {1}{\pi c^2} \int \limits _{r=0}^c 2 \pi r\ e^{-\frac { \left ( \sqrt {a^2 - r^2} -\sqrt {b^2 - r^2} \right )}{\lambda }}\ dr \] under the conditions \(a>b>c>\)...
asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245673
This has been annoying me for a long time. I want a rational function to be represented in the form \[\frac {a_nx^n+....a_0x^0}{b_mx^m+....b_0x^0}\] But this seems to be quite difficult. Mathematica ...
asked by grdgfgr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=28163 2 votes
answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245078
My code replaces each repeated element by "X".
asked by azerbajdzan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53172 10 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2450308
Good day. Let’s take an example from Help on RecurrenceTable
asked by macros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79485 6 votes
answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245121
I deals with a coupled system with non-linear differential equations of first order. I perform numerical solution with NDSolve and then use obtained solutions,
asked by Artem Alexandrov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49992 5 votes
answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245050
Suppose you have region with 2 materials: one embedding material matrix containing some particles
asked by Mauricio Fernández https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24710 4 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245080
I am currently writing a paper in which Fibonacci Spirals are discussed. In the text of the paper the mathematics of these objects is discussed and the relevant equations and relationships are shown ...
asked by urquiza https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79636 4 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245068
Is there a way to write a function where the input is a vector and the output is the elements in the vector that are repeated? I was trying to use something along the lines:
asked by Trashlife https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79628 4 votes
answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245051
I want to separate two regions in DensityPlot similar to the attached image.
In my code and the obtained result, I want to separate the region with less value of one from others. How can I do this? ...
asked by mehrosadat ebrahimi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40575 4 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=24169
I’m new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations.
For example in sphere’s case \(x^2+y^2+z^2=1\)
I tried to use ...
asked by German https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7145 8 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538
I want to get the following expression from Mathematica to LaTeX:
\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \]
I have tried to use inbuilt ’symbol’ character from the special ...
asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 20 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 27 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19076
I’m trying to plot a function of the form \(z(r,\theta )\) where \(r \in [0, R]\) for a finite R, \(\theta \in [0,2\pi [\), and z is the third coordinate, a function of the first two. I couldn’t find anything ...
asked by Learning is a mess https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5643 19 votes
answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 26 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2371758
I am looking for an ELI5 explanation of whatCompile[]
in the Wolfram Language context
does and why it works so much faster than uncompiled code in certain cases. I am trying to
get more insight to ...
asked by anon248 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66458 20 votes
answered by chasly - supports Monica https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34024 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=850
Is there some way to do this other than going to Evaluation -> Quit kernel
and firing a
new one up?
asked by niklasfi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82 99 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 98 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433
I am using this code to plot a graph, and I am trying to make the font of the legend bigger.
asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8841
I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...
asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 33 votes
answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 26 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2451018
I am trying to reproduce the following graph of phase shifts as function of frequency.
Please see my code bellow. I used Mathematica to solve for t1 and ...
asked by guestuser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76488 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=245194
I need to solve the following system of (infinitely many) equations. I am looking for \(V(0,0)\)
\(t \in \{0,1,2.....\}\) with one caveat that \(s \leq 1+t\) should hold.
\( s \in \{1,2,3,L-1\}\)
fixed ...
asked by Monire Jalili https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62240 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2452988
I am constructing polynomial expressions in the variables \(s[0],s[1],...,s[n]\) and I’m trying to define a new operation to simplify the expression:
asked by David https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72836 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244887
I have three lists:
x = {x1, x2, ...}, y = {y1, y2, ...}, yErr = {y1Err, y2Err, ...}
that I want to join into the following format:
asked by uuu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42359 7 votes
answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244672
There are two ways (afaik) to parse traditional math string to an expression:
asked by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 7 votes
answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244907
Could you help me, please? I have two complex functions of real variable f[x] and fc[x]
such that one is a conjugate of another one. I’d like to take a conjugate of an expression that
includes both of ...
asked by Svetlana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72941 6 votes
answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244820
How to pack n equal disks(radius a/2) with maximal area inside a given rectangle ? I’m trying to solve this problem using Mathematicas Region functions. Here my approach: Maximize the area of the ...
asked by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 6 votes
answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244961
I need to perform the following operations using Wolfram Mathematica. I have these equations: \[a b = c+d+e\] \[\frac {d}{f}=g h + i\] \[k=\frac {a}{c}\] I need to obtain \(k\) as a function of: \(a,b,c,e,\dots \)
asked by Skyhawk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79597 5 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244834
If I have a list:
{ball,ball,BINDIVIDER,ball,ball,ball,BINDIVIDER,BINDIVIDER,ball,BINDIVIDER,ball}
The balls and bins can be in any permutation. Then, the ...
asked by apkg https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35029 5 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244993
Suppose you have an elastic cylinder of radius \(R\) and height \(H\) and you want to solve the mechanical 3D equilibrium with Mathematica’s FEM. How do you impose a pressure \(p\) only on the cylinder ...
asked by Mauricio Fernández https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24710 4 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5910
I have data in file.txt which can be expressed by 20000x11
matrix. I do not want to import
all of these data. How can I plot graph of the column 1 & column 4?
asked by Gokce https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1297 21 votes
answered by user1066 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043
Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...
asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes
answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 485 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 288 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937
Salacious title, but true story.
asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes
answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236499
Christmas is around the corner! In preparation, consider the polynomial
f[x_,y_]:= 1/10 (4 - x^2 - 2 y^2)^2 + 1/2 (x^2 + y^2)
and define \(r=(f_x,f_y)\) using the ...
asked by fwgb https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44151 30 votes
answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 22 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306
I have a complex expression with real positive variables only.
Mathematica Input Style:
asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 34 votes
answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 53 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244963
this is my very post here, so I apologize for any possible format issue. I am using HypergeometricPFQ functions (more exactly \(_3F_2\)) as approximants for other more complicated functions. Here are ...
asked by avg https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79519 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244663
Can I recursively extract StringCases[]
that match a specific pattern? Here is a minimalist
example (not my actual problem):
asked by Conor Cosnett https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36681 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244702
How can I use Predict[Xs->Ys, Method->"NeuralNetwork"]
to predict 90%-quantile
(instead of mean value)? Utility Function does not work well for this case, because
it assumes ...
asked by Artem Vorozhtsov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61755 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244314
I want to swap the list to make a new list as follows. The code works but I’m wondering if there is a neat code, or an elegant way to do this.
asked by anhnha https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18805 9 votes
answered by kirma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3056 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244482
This is a follow-up to a previous question (see here). We would like to solve the two-dimensional Stokes equations using the FEM package in Mathematica, when we prescribe traction boundary conditions. ...
asked by Alex R https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=78043 7 votes
answered by Oleksii Semenov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63028 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244566
I came across the need to transform a number into a factorial n, with positive integer n. I have searched in the MMA information but I can’t find anything like that. I imagine an input, which verifies ...
asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 7 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244313
This seems like it should be a simple question – but I am looking to use a "home made" stopping condition with FindMaximum, while evaluating a very complex function. Printing out the ...
asked by Richard E https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79342 7 votes
answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244565
Given a 2D Mathematica Region, e.g. A = Region[RegionDifference[Disk[{0, 0}, 2], Disk[{2, 0}, 1]]]
,
how can I grow the region by an arbitrary radius r? For example, ...
asked by Aaron T. Becker https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76690 6 votes
answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244316
Is there a way to generate real random orthogonal matrices in mathematica? If Q is an orthogonal matrix, it’s properties are
asked by Jasmine https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73364 6 votes
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244592
If we create a random graph
Chop[LowerTriangularize[RandomReal[{-1, 1}, {10, 10}], -1], 0.6] /.0 -> \[Infinity] // MatrixForm WeightedAdjacencyGraph[%]
How can ...
asked by Teabelly https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=56986 5 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139
In Wolfram Mathematica the function Fourier has the following declaration
Fourier[list]
And after a list is given to the ...
asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes
answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859
I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:
x1 y1 x2 y2
asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 47 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=148
Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?
asked by Cydonia7 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44 131 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 109 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3561
In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 64 votes
answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 83 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=64003 I have a list:
data = {4, 5, 7, 8, 9, 5, 3, 2, 1, 2, 13, 12};
I want to take those elements in the list which are located at equal distances, say, every third ...
asked by Suro https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=20003 37 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 34 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=24169
I’m new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations.
For example in sphere’s case \(x^2+y^2+z^2=1\)
I tried to use ...
asked by German https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7145 7 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521
I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to
Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2)
. How can I do
this?
asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 4 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244335
Consider the following scene as an example:
asked by user13892 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13892 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244342
I want to solve the following differential equation f''[z] + (1/z)*f'[z] - f[z] + f[z]^3 == 0
subject to the boundary conditions
asked by HeitorGalacian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73726 1 vote
answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=244387
How to draw spheres with BubbleChart with a reversed vertical axis? The 3rd example shows the problem (empty plot), likely caused by the transformation, but how to correct it?
asked by HuibH https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70256 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243660
Are the maps available in Mathematica copyright-free? For instance, if I generate the image
asked by sam wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=64001 13 votes
answered by Carl Lange https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57593 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243664
This question is majorely influenced by a meme...
Now, I thought... it would be interesting to see what kind of "passwords" could one derive using Periodic Table :D Hence, I began to work ...
asked by e.doroskevic https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18696 9 votes
answered by creidhne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41569 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243547
I want to uniformly sample \((0,1)\)-matrices with certain constraints. In particular, I want sum of each row to be rowsum and the sums of columns to equal ...
asked by kirma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3056 8 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243711
Recently I came across an interesting article by Daniel Lichtblau, where the integral
Integrate[Abs[x - y]^n, {x, 0, 1}, {y, 0, 1}]
asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 7 votes
answered by Ulrich Neumann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53677 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243859
In this previous question I looked into a deprecated capability of Mathematica from Version 2. Mathematica command that allows it to read my intentions Thanks to all for your answers. I note that ...
asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 6 votes
answered by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243823
I’m trying to put together several different 2D plots in a 3D graphics to create a figure which would be like the one below (taken from https://aip.scitation.org/doi/10.1063/1.4998724 However my ...
asked by AntoineM https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79171 6 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243776
Suppose I have a dataset, which I want to sort according to two criteria. However, I want the first criteria to be sorted ascending, and the second descending. This would require to somehow combine ...
asked by Gabriel Landi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=347 6 votes
answered by SquareOne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19960 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=198839
https://blog.stephenwolfram.com/2019/05/launching-today-free-wolfram-engine-for-developers/
http://www.wolfram.com/engine/
The Free Wolfram Engine for Developers is available for pre-production ...
asked by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 65 votes
answered by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 55 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184
I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...
asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108
I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?
If not, is there a way ...
asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=37266
Today, I found the Euler Project. Problem #2 is
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
asked by xyz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9627 34 votes
answered by rcollyer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=850
Is there some way to do this other than going to Evaluation -> Quit kernel
and firing a
new one up?
asked by niklasfi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82 99 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 98 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336
I am wondering how to implement the multi-peak detecting and fitting in Mathematica.
Following is an example of fitting the data using three peaks (such that the
data ~ peak1 + peak2 + peak3
). The ...
asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 55 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 55 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243708
I do not understand this statement from the Introduction to Dynamic tutorial:
asked by Dave https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79143 1 vote
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243637
I’ve noticed that wrapping a Graphic[] in Hyperlink[] causes weird things to happen when using ...
asked by Mike H https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=79121 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=243849
I’m working with square polynomial systems and wish to know if a (small) system has a finite number of solutions. That is, if it’s zero-dimensional. I’m not aware of any built-in function to do this ...
asked by Dominic https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47466 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242183
Can we say Head[x] and x[[0]]
are identical ? In mathematica manual I could find : ’The
head is the part with index 0’
But I am not sure whether Head[x] are x[[0]]
are really interchangeable in any
...
asked by imida k https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34532 15 votes
answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242180
I want to roll the function f(x)=sqrt(x), x[0,1]
along the y-axis. I know how to rotate
the graph around a point, but I’m not sure how to rotate along an axis in 2D. Rotating
around a point e.g. (0,...
asked by Guy Foxx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75736 14 votes
answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 17 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242138
Hi I am new to using Mathematica, so am not too confident. I am essentially trying to model vibrations of a guitar sound board for a project. It would be great to get some visualisations of the ...
asked by sp96 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77970 11 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242140
How to set the options or other parameters in a TreePlot to draw the branching outside of the vertex? I.e. in a form similar to a dendrogram (but the dendrogram plot itself does not support the ...
asked by Slepecky Mamut https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=48033 10 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242186
I want to quantify the flow from photos taken from a sensor such as this one:
For a limited number of readings, I can use a plot digitization method. However, I need to do this many times for ...
asked by MathX https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38575 9 votes
answered by MelaGo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63360 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242030
I want to compute the automorphism group of a matroid. This reduces to the following (more general) problem: Suppose I have a list of sets \(\{\{b_{11},\dots ,b_{1k}\},\dots ,\{b_{k1},\dots ,b_{kk}\}\}\) ...
asked by Madeline Brandt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51040 7 votes
answered by Madeline Brandt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51040 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242425
Is there any way to make a circular heat map in Mathematica? Thanks for your help! Here is a toy example for regular heat map. Can anyone help me make it to a circular one?
asked by Frankie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70269 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8885
How can I draw the 5 interlocking Olympic rings with Mathematica? (SVG version) Edit
Hard choice, but some pretty cool answers here. I didn’t have 3D answers in mind when I posted the question, but ...
asked by Mike Honeychurch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77 44 votes
answered by cormullion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859
I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:
asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 47 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6738
(Newbie question)
For every function I define I get this message: When I close and reopen Mathematica, and re-enter the function definition, I don’t get the message anymore. What does it mean?
asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 11 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=64003
I have a list:
data = {4, 5, 7, 8, 9, 5, 3, 2, 1, 2, 13, 12};
I want to take those elements in the list which are located at equal distances, say, every third ...
asked by Suro https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=20003 37 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 33 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience,...
asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 63 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 47 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819
In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 201 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 261 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18082
testData = Table[N@Sin[500 x], {x, 0, 100}]; ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full]
Gives me Which I do not expect because the Fourier ...
asked by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 14 votes
answered by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242074
In mathjax \mathscr{C}
gives me the character $\mathscr{C}$
that I want. There is a
UTF listing for this character. https://www.compart.com/en/unicode/U+1D49E If I copy
form this webpage and paste ...
asked by Steven Thomas Hatton https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44139 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242097
I want to create a FormFunction that takes in a CSV file, applies some operations on the data and outputs another CSV file. I would like for the ouput CSV file to be automatically downloaded. I have a ...
asked by Gabriel Landi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=347 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=242436
This question is in continuation of the my previous question that was not clearly presented by me at all. I have a unit cell, and I would like to generate a lattice but in iterative order. For ...
asked by L.K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=15927 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241791
I am getting these results:
asked by Craig Carter https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12461 20 votes
answered by Chip Hurst https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4346 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241712
We can declare a function to have the Listable Attribute so that it automatically threads over lists in a particular way. For functions of multiple arguments it ...
asked by Tanner Legvold https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68925 14 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241686
For a curve taken from a picture, is there any method to fit it with an equation if it appears to be some standard curve? For example, in the following picture, the curve looks like an ellipse or a ...
asked by Nobody https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66106 10 votes
answered by mikado https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36788 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241573
Working in the creations of APIs with Mathematica 12.2, I got this problem with diacritics when sending JSON data. Here is a toy code using httpbin.
asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 10 votes
answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241876
I’m trying to make a "main effect" type chart but I haven’t found a way to do it in Mathematica. The main effect plots are the graphs plotting the means for each value of a categorical ...
asked by ALEXANDRE ARARIPE https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77894 7 votes
answered by MassDefect https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42264 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241943
I would like to generate all the tuples of ones and zeros of a given length and with a given number of ones without generating all the possible tuples, which is impossible for tuples of large enough ...
asked by EGME https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53849 6 votes
answered by Roman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26598 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241642
Wolfram Mathematica 12.2 now features "Named Partial Differential Equation Terms"
For specific physics fields, relevant PDE terms have been packaged as components and augmented with ...
asked by rhermans https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10397 6 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18082
testData = Table[N@Sin[500 x], {x, 0, 100}]; ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full]
Gives me Which I do not expect because the Fourier ...
asked by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 14 votes
answered by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378
I’m visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something ...
asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 45 votes
answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...
asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 622 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 483 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase ...
asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 17 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 33 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668
If you enter the following into Wolfram Alpha, you get nice graphs:
graph 4 x^4 + y^2 = 2
How do you do this in Mathmatica? I realize that these are not ...
asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 39 votes
answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 40 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235815
During these days of COVID, I indulged in the guilty pleasure of watching The Curse of Oak Island - Season 8, Episode 4 Alignment, which viewed last night (1 Dec 2020). During the episode, some "...
asked by Jagra https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=571 13 votes
answered by Carl Lange https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57593 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241851
The documentation of ColorFunction states that in ListContourPlot3D your chosen function gets the arguments ...
asked by Fidel I. Schaposnik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45839 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241842
When typing Importin a notebook Mathematica suggests to autocomplete the file path you want to enter or choose a file using the GUI. Is there a way to let a ...
asked by Gert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27889 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241633
I am trying to find six integer numbers a, b, c, x, y, z so that the angle of two vector
{a, b, c ...
asked by minhthien_2016 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5320 1 vote
answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241402
I would like to code a Metropolis Hasting algorithm and thought I would get the general scheme of things going with a toy example.
I think I got it running but my Mathematica code runs significantly ...
asked by Smerdjakov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=55615 13 votes
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 22 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241234
I started building this Manipulate and am certain I can do so on my own, but thought it was fun enough that others might want to try. (If this is some abuse of the ...
asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241231
I have a question in respect of the BoxWhiskerChart. The default functionality of BoxWhiskerChart is that you mouse over it and ...
asked by Jiri https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77351 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241087
I need to determine how many strictly increasing sequences of a certain length (e.g. 5) are contained in a list of integers. I would be very happy if someone could help me. A sequence would be ...
asked by hnh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77559 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241086
I am trying to calculate the pressure required to flatten a bowed wafer. The simple model I am using for the study has a bottom layer (the bowed wafer) pushed against a harder flat surface as shown in ...
asked by martin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77626 8 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241503
This question is solely based upon \([1]\) and therefore, the reading of \([1]\) could be interesting. How can I export the image created, by the code in the following, with high definition, beautiful, 4K ...
asked by M.N.Raia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71570 8 votes
answered by thorimur https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63584 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241405
Is is possible to add a skewed grid in a plot? Consider the following image;
The grey axes are the normal axes (\(\mathbf {e}_1\) and \(\mathbf {e}_2\)), the black axes are transformations \(\mathbf {e}'_1=2\)
asked by mf67 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=55498 8 votes
answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=86058
Python’s family of packages for scientific computing has matured rapidly. I can pretty much replicate all of Mathematica’s functionalities, but with production level and open-source code using the ...
asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 49 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 36 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1542
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
asked by Matthew Leingang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=395 109 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 88 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987
I would like to display an electromagnetic (EM) wave. I have written code that works, but it does not "shade" the area between the graph and the axes. Both the ...
asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 22 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881
Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:
1) Continuous GIF animations with smallest possible number ...
asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 40 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 54 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19546
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The problem
asked by s.s.o https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=840 64 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 59 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image< with Mathematica and plot the magnitude and phase ...
asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 17 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 33 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 482 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 288 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241216
I’m using Mathematica 12.2 on Ubuntu Mate 20.10 on an AMD FX(tm)-8120 with a GeForce GTX 1070 Ti NVIDA card. The issue is that I get unwanted horizontal lines just below the cell that I’m working on ...
asked by c186282 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4515 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241097
I was wondering how can I find What is the minimum differencing order needed to remove the trend in a time series? I have a a times series and a TimeSeriesModelFit, which is SARIMA model. I want to ...
asked by Pjana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75643 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=241245
Following up from @kglr's
answer here, I’d like to understand how TextureCoordinateFunction[]
works within SurfaceAppearance[]
. ...
asked by martin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9923 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240449
SUMMARY: If a List,TimeSeries etc. of Around objects contains any identical elements,
asked by Aaron Eiben https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72186 14 votes
answered by Sjoerd Smit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43522 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240596
I don’t understand how to manipulate numbers with repeating decimal in Wolfram Mathematica language. For example 0.3... does not work as input and I don’t see how ...
asked by Simpleton Jack https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22399 9 votes answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240325
There’s a set of arrays that I want to remove repeated elements that are equal after rotation:
asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 9 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240522
The expression 1+Sqrt[2]I-Complex[1,Sqrt[2]]
should be zero. In fact,
N[1+Sqrt[2]I-Complex[1,Sqrt[2]]]
yields ...
asked by pdmclean https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9154 7 votes answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240357
Four couples a are sitting around a round table, in which husband and wife can not be adjacent. How many different seating plans are there? I want to get as many simple calculations as possible.
asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 7 votes
answered by Beny Izd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77079 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240461
What’s the mathematica command to get the numerical value of : \[PV\int _0^\infty \frac {\tan x}{x}\text {d}x?\] where \(PV\) is the principal value.
asked by Ali Shadhar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67714 7 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240571
I need to display a directed acyclic graph (say Hasse diagram of partial order) oriented with minimal elements at the bottom, maximal elements at the top as is conventional for Hasse diagrams. I tried ...
asked by Mike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62210 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736
I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems
I would ...
asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 127 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184
I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...
asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...
asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 620 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 481 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544
Is there a way to find a limit of a multivariable function, like
\[\lim _{(x,y)\to (0,0)} f(x,y)\] with Mathematica?
When \(f\) is continuous, we can use \[\lim _{(x,y)\to (0,0)} f(x,y)=\]
asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 31 votes
answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 42 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4643
I’d like to know how can I call Mathematica functions from Python.
I appreciate a example, for example, using the Mathematica function Prime.
I had search about MathLink but how to use it in Python ...
asked by GarouDan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1058 69 votes
answered by GarouDan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1058 28 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5910
I have data in file.txt which can be expressed by 20000x11 matrix. I do not want to import all of these data. How can I plot graph of the column 1 & column 4?
asked by Gokce https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1297 21 votes
answered by user1066 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=42359
Following is the equation: Need to solve for integer values of x,y when a,b lies between -1000 and 1000. Problem is to find the number of integer values of pair (x,y) that satisfy it.
asked by Sahil Sareen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12396 2 votes
answered by bill s https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1783 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240468
I would like to know a more idiomatic way to subtract a function from a list of pairs than
this: Table[point-{0,fitFunction[point[[1]]]}, {point,data}]
I use this ...
asked by Diffycue https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46327 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240422
My question is about simplifying tensor expressions. If I have \((a+b)\otimes (c+d)\) The function TensorExpand gives \(a\otimes c + a\otimes d + b\otimes c + b\otimes \) ...
asked by Physor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74507 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240457
I am trying to make 2 log log plots. One with each equation, a and g. I don’t know why, but the plot is not showing up. My notebook is in the link below. https://imgur.com/a/sXQX0YS
What am I doing ...
asked by QuaffyWaffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77475 1 vote
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239914
Working with students in a pre-calculus class, an application of the sine law. They are working on a question that has them create a Golden Triangle (A golden triangle is an isosceles triangle in ...
asked by Tom De Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=721 14 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239960
I try to make a dark stylesheet based on the ReverseColor theme. However, dataset headers are barely readable.
This question is related to others such as Question ...
asked by Vly https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47700 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239946
For example: PolarPlot[{1, 1 + 1/10 Sin[10 t]}, {t, 0, 2 Pi}]
how to fill color in the space between 2 functions?
asked by DORA https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74396 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239874
I use by hand to get this result \[\sqrt {48+5 \sqrt {3}+\sqrt {27+4\sqrt {3}+\sqrt {12+3 \sqrt {3}+\sqrt {4+2\sqrt {3}}}}}=1+4 \sqrt {3}\]
asked by minhthien_2016 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5320 7 votes
answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240123
Suppose I have a matrix ’mat’ as
mat = Table[Subscript[m, i, j], {i, 5}, {j, 5}]; mat // MatrixForm
I want to extract the first column (or any row) as
asked by PoreyS https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54258 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240149
When I read Wolfram’s post about the new features in MMA 12.2 I was intrigued by
RemoteBatchSubmit[]
. He wrote:
I have only ever used MMA from my laptop, and never used any other cloud computing or ...
asked by TumbiSapichu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53229 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240090
I am trying to solve the following heat equation problem on the square [0,1]x[0,1]. \begin{equation*} \begin{gathered} u_t = u_{xx} + u_{yy} + f(x,y,t), \qquad u(x,y,0) = 0, \qquad u=0 \text{ on ...
asked by kroner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77278 6 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=143691
Deep convolutional neural networks are very good at computer vision related tasks. Optical Character Recognition (OCR) is one important branch of computer vision. In fact, the convolution neural ...
asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 88 votes
answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 98 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3345
How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 86 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1542
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
asked by Matthew Leingang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=395 109 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 88 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982
Here is a start.
MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 57 votes
answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 73 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704
Wolfram|Alpha has a whole collection of parametric curves that create images of famous
people. To see them, enter WolframAlpha["person curve"]
into a Mathematica
...
asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 85 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987
I would like to display an electromagnetic (EM) wave. I have written code that works, but it does not "shade" the area between the graph and the axes. Both the ...
asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 22 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240016
I have a list in the following form: list = {{a,1,3},{b,1,3},{c,1,3}}
Now I want to apply this list as parameters for the Sum function so that I end up with the ...
asked by Hell stormer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77333 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=240056
Trying to run some wolframscript code from a server, is it possible to set ServiceConnect credentials in the environmental variables for example?
asked by Tim https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=416 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239861
I have a system of differential equations, given by
asked by No name https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69573 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239480
Using Chicago as an example; According to the current rules for applying daylight saving
time, at 02:00:00
on the first Sunday of November, clocks in Chicago go back 1 hour (from
Central Daylight Time ...
asked by RobertNathaniel https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60404 24 votes
answered by Patrick Stevens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30771 22 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239455
I have the following dataset:
asked by Whelp https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1287 10 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239609
This plot has 40 curves on the same graph which makes it hard to see. I need to plot them on one graph. So I have an idea to plot to make it easier to see which one is larger or smaller in each range....
asked by anhnha https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18805 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239659
Consider a named BlankSequence x__. How can I access the n-th element? Is {x}[[n]] the only ...
asked by Money Oriented Programmer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239512
From Carl Woll’s answer here, I have this code for pulling the von Neumann neighbors:
asked by TubularHell https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76599 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239518
Numpy has a newaxis object that allows you to insert a new dimension of length 1 into an array. So after ...
asked by Dan Piponi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13642 8 votes
answered by swish https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2490 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239728
Consider
Plot[Im[(1 + (-1)^(2/3)*x)/((-1)^(2/3) + x)], {x, 0, 1}]
At least in Mma 11 it gives the following picture: Meanwhile,
asked by Roma Lee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57495 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881
Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:
1) Continuous GIF animations with smallest possible number ...
asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 40 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 54 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506
I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a ...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7142
When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 137 votes
answered by IstvánZacharhttps://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 155 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586
I am trying to use the Export command to convert a list of plots into a *.gif
file,
and the command runs and executes well, but I can’t find the file! Where is it
...
asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233050
I found this image on the Internet and it is very beautiful. How can I reproduce it? The ideal would be to be able to control the colors of the outside as well as the center.
asked by Susana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37778 14 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 35 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19669
Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 167 votes
answered by faleichikhttps://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 241 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18082
testData = Table[N@Sin[500 x], {x, 0, 100}]; ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full]
Gives me Which I do not expect because the Fourier ...
asked by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 14 votes
answered by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239754
Like in the table of transforms https://en.wikipedia.org/wiki/Fourier_transform#Distributions,_one-dimensional the FT (Fourier transform) of \(\delta \) is 1 and the FT of 1 is \(\delta \), but in polar ...
asked by user740332 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76926 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239664
How can I have Mathematica represent the product of two different bases and exponents as a single power (where possible)? For example, see the product below can be expressed below:
asked by Steve237 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69429 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239796
I obtained the data for the real and imaginary parts of a complex function \(A(x,t)=A_r(x,t)+i A_i(x,t)\) from NDSolve, both are functions of time \(t\) and space \(x\). ...
asked by Enter https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19178 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239250
Version 12.2 brought us Confirm and Enclose. What’s the point? Is it just that it’s a slightly more convenient syntax than ...
asked by Patrick Stevens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30771 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239072
I am currently changing a notebook into a wolframscript for a "production" environment, where I plan to pack the script as a standard CLI tool. However I do not know how to implement such an ...
asked by Gravifer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72025 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238999
What is the default method used by FindMinimum with constraints? The documentation says:
"Currently, the only method available for constrained optimization is ...
asked by VarunM https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69094 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239220
MeshRefinementFunction works well to refine elements in a defined spatial domain (here \(x>0\)):
asked by Oscillon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13605 8 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239255
I had a more general question about a similar problem more than two years ago, Getting rid of discontinuities in plots caused by square roots, logarithms, ‘Arg‘, etc, which got lots of interesting ...
asked by https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35000 8 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239294
My goal is to generate diagrams like this.
But I would like to be able to rotate the globe about the North Pole, so that I can represent different times of the day. When I use ImageRotate, the ...
asked by David Elm https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44449 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239303
I found DelaunayMesh works fine for 2D. For example,
asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 7 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521
I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to
Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2)
. How can I do
this?
asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 4 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306
I have a complex expression with real positive variables only.
Mathematica Input Style:
asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 34 votes
answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 53 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6669
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 56 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 34 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2116
According to the Mathematica help: Round rounds numbers of the form x.5 toward the nearest even integer. For example:
Round[{0.5, 1.5, 2.5, 3.5, 4.5}]
gives
asked by wxffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=427 83 votes
answered by Per Alexandersson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=488 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586
I am trying to use the Export command to convert a list of plots into a *.gif
file,
and the command runs and executes well, but I can’t find the file! Where is it
...
asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433
I am using this code to plot a graph, and I am trying to make the font of the legend bigger.
asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139
In Wolfram Mathematica the function Fourier has the following declaration
Fourier[list]
And after a list is given to the ...
asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes
answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239047
For the function fun[a_, b_, x_, y_] = Sin[a x] Cos[b y] (a x + b y);
corresponding to \(x\) and \(y\), I need a RegionPlot showing the maximum of function
\(fun[a, b, x]\)
asked by Mike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76947 1 vote
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239107
I have the following code in mathematica which runs perfectly for a small matrix of 21 x 12 matrix. But I really want to test it for a large system. My data is 35844 x 21000 elements, totaling 1.5 GB. ...
asked by shixx597_Min https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59772 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=239335
When I evaluate
asked by user824530 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75136 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238880
I have 2 associations similar to these simplified ones:
asked by Coolwater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9754 16 votes
answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238735
As a hobby, I am trying to use Mathematica and Wolfram Language as a tool for making generative artworks. Generative art techniques may require drawing millions of points, lines, or curves. For ...
asked by mikabozu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74721 15 votes
answered by George Varnavides https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41179 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238849
I am trying to make a 3D contour plot that looks like a grid of cylinders to represent the Fermi surface of a metal, like below:
I have no problem generating something that kind of looks like it.
asked by Nick https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76998 10 votes
answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238742
Here’s Giorgio de Chirico’s painting, Ariadne:
The Surrealist artist deliberately broke the rules of geometric perspective, giving the work his characteristic sense of mystery and unease. What would ...
asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 10 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238591
frames=Table[Plot[Sin[x(1+a x)],{x,0,6}],{a,0,2,0.2}]; Export["test.gif",frames]
The above code runs in version 9.0 to get a infinite looping GIF ...
asked by expression https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7339 10 votes
answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238687
Is it possible to identify a color (say grey in a 3 color Black, Gray and White image) and ...
asked by skyfire https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70181 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238705
DiscretizeRegion doesn’t seem to run the supplied MeshRefinementFunction when meshing a 2D surface in 3D. For example:
asked by alessandro https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42454 7 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11982
I have some code that looks like
Table[ a = 1; b = {2, 3} c = i;, {i, 2} ] which gives an error: Set::write: Tag Times in c {2,3} is Protected....
asked by dearN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=204 29 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 35 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience,...
asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 63 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 47 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3561
In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 61 votes
answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 82 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66969
Here is a start. I’m looking for a nice way to draw it.
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 24 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=15023
The basic multivariable Taylor expansion formula around a point is as follows:
asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 63 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 71 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763
When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)
asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes
answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=194384
In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ] which allowed it rapidly compose code that could solve problems simple to complex, ...
asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 52 votes
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 38 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238887
The aim of my work is to find a value for the complex constant \(\omega \). In order to do that I solve the below system of differential equations with a manual shooting method: I first solve the system ...
asked by mattiav27 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8822 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238596
I’ve been trying to solve this initial value problem using DSolve[]
:
\[ \frac {dy}{dt}=1+t\space \sin (t\space y),\quad y(0)=0, \quad t=[0,2] \]
asked by Walser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60465 1 vote
answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238719
I have a 3D volumetric data (for example, \(64\times 64\times 64\), at each point there is a value) read in from a file and I want to use ListDensityPlot3D to ...
asked by Dennis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69969 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238461
I have a logic puzzle I want to convert to Mathematica to solve: Person A states, "Exactly two people are truth-tellers," Person B states, "I and Person C are truth-tellers."
asked by Peter Burbery https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76873 16 votes
answered by SneezeFor16Min https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69875 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238293
I want to create the list ix={1,1,1,1,2,2,2,2,3,3,3,3,4,4,4,4}
I can do
asked by geom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68502 11 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 20 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238321
I encountered such expressions in Mathematica
MeijerG[{{ }, {1, c + 1/2}}, {{0, c, c, c}, { }}, 1] + MeijerG[{{1}, {c + 1/2}}, {{c, c, c}, {0}}, 1]
which in ...
asked by Jing https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76801 8 votes
answered by Chromo Runge https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68326 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238440
I am teaching the idea of infinite geometric series to high school students, looking for hints to create the diagram below using Mathematica. (I don’t need the labels). I can do it manually, but ...
asked by Tom De Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=721 7 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238501
There is a curious example in Posamentier’s book "Magnificent Mistakes in Mathematics" (p. 72): \((7+3/7)*(4-3/13)= 7*4=28\), where cancelling the fractions leads to correct result. If we ...
asked by Darko G https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60625 7 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238335
In the following the full context form of Test is not required as "Aaa`"
is added to
...
asked by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 6 votes
answered by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238268
...
asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 6 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035
Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?
asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 43 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 48 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 52 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 67 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting ...
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 18 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 30 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184
I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...
asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=37266
Today, I found the Euler Project. Problem #2 is
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
asked by xyz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9627 34 votes
answered by rcollyer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293
I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,
\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)
where U(x) is some potential and Ei is the ...
asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 49 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108
I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?
If not, is there a way ...
asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238481
Starting from a data set like the one used in this post: Importing and visualizing 4D data DATA It can be viewed using ListDensityPlot3D, as follows:
asked by Ivan Y. Forero https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76882 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238231
Consider the partial differential equation
asked by beginners https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76785 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238500
With this code we can make 2D FEM simulation of transonic flow around airfoil NACA 0012 at Mach number of 0.925. It takes about 5 minutes on the XENIA-15 laptop of 32 GB memory with processor Intel ...
asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237884
The closest pair of points problem is a common computational geometry problem: given n points, find a pair of points with the smallest distance between them. A naive algorithm of finding distances ...
asked by Aaron T. Becker https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76690 17 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237871
f[x] ^= 1; ValueQ[g[x]]
returns True in Mathematica 12.2. Is it a bug?
asked by Roma Lee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57495 15 votes
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 17 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237994
12.0.0 for Microsoft Windows (64-bit) (April 6, 2019) How do I get my graphic to look the same in PDF as it does in a Notebook? This is what the graphic looks like in the FrontEnd:
This is how the ...
asked by Steven Thomas Hatton https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44139 10 votes
answered by MelaGo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63360 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237903
Recently I learned that in Mathematica it is possible to create chemical structures here: Chemical formulas with Mathematica I am having a problem with a structure called "Sucrose benzoate"
asked by John https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72940 9 votes
answered by Jason B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9490 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238163
I have Echo’s buried in code all over my notebook, I’d like a flag to turn them all on or off globally.
Sure Unprotect[Echo];Echo=Identity
would disable them, but ...
asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 6 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238018
I was surprised to see that, in the results of CompilePrint for a function made with Compile, calls to ...
asked by Sean https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76328 6 votes
answered by Sean https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76328 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237914
I have a list of pixels centers, for example :
asked by yfs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71775 6 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5790
If we have two vectors, \(a\) and \(b\), how can I make Jacobian matrix automatically in Mathematica?
$$ a=\left( \begin{array}{c} x_1^3+2x_2^2 \\ 3x_1^4+7x_2 \end{array} \right);b=\left( \begin{array}{...
asked by George Mills https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1012 39 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 52 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3458
Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 42 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 29 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26268
This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ...
asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 196 votes
answered by halirutan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=187 192 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=1987
I would like to display an electromagnetic (EM) wave. I have written code that works, but it does not "shade" the area between the graph and the axes. Both the ...
asked by Rainforest Frog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=202 22 votes
answered by J. M.’s ennui https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108
I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?
If not, is there a way ...
asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11868
Why I get the error below with this code:
asked by Aurelius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1669 10 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=86058
Python’s family of packages for scientific computing has matured rapidly. I can pretty much replicate all of Mathematica’s functionalities, but with production level and open-source code using the ...
asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 49 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 36 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237920
For the following equations;
asked by confused https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74890 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237834
Since v12 FindFit[] now supports regularisation, such as Tikhonov regularization. Do there exist statistics to help guide the choice of the hyper-parameter
asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=238106
Expand floods all my 64GB RAM in MMA 12.1 (Windows). Therefore I cannot run the code. Somebody with >64GB RAM could give the result. A memory saving alternative ...
asked by granular bastard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69288 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237547
I have the following simple expression Exp[(Log[1 + x]^2 - Log[x]^2)/Log[1 + 1/x]] - x^2
that can be shown to simplify to \(x\)
asked by user16320 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16320 13 votes
answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237692
The vertex A,B of the square ABCD with side length \(\sqrt {2}\) is on the circle with radius \(\sqrt {2}\), vertex C,D is inside the circle, roll the square ABCD along the inside of the circle ...
asked by expression https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7339 10 votes
answered by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237533
I’m lazy writing equations in Latex so I want a code to translate handwritten equations. This question is related to an old experiment I’m reviewing during vacations, here. I’m trying to use ...
asked by Gluoncito https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8696 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237458
I am using a function with a lot of variables. There are 9 and sometimes more of them. In this case, it is difficult to memorize, which one stays on the, say, fourth position, and which one - on the ...
asked by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 8 votes
answered by CA Trevillian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63039 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237681
How to make this faster? I want to remove elements that satisfy the condition below but it’s way too slow.
asked by anhnha https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18805 8 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237785
I’m using Mathematica 12.1.1.0. When I enter
asked by Jason Gross https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12258 7 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237678
I am using M12.0.0.0 on Ubuntu and I have these two plots:
asked by valar morghulis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26937 6 votes
answered by Rolf Mertig https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139
In Wolfram Mathematica the function Fourierhas the following declaration
Fourier[list]
And after a list is given to the ...
asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes
answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8841
I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...
asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 31 votes
answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=100072
I’m 13 years old and in 7th grade. I’m currently in Algebra 1, and I have fallen in love with both math and programming.
When I came upon Mathematica, it was awesome. My two favorite things fused ...
asked by Nico A https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35769 81 votes
answered by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 55 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 52 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 67 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573
I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...
asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes
answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521
I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2). How can I do this?
asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 4 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598
For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).
I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...
asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 44 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237480
I wonder if there is a function in Mathematica (or code) that can help obtaining inverse 2D
Laplace transform of a function, f(s1,s2) which is the 2D Laplace transform of a function
F(t1,t2) in (s1,s2)
...
asked by Refaat Galal https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76583 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237541
I am an aspiring data scientist who’s working on a passion project, namely to assign danger-level scores to police departments in the United States. One specific metric I’m developing results from ...
asked by uselesslemma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72297 3 votes
answered by George Varnavides https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41179 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237484
A classic problem in computer vision is computing correspondences between keypoints in two similar images, despite modest variations in size, lightness, orientation, etc., of the images, as ...
asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236895
These 399 PDE’s no longer produce result under Version 12.2 on windows. DSolve now returns unevaluated. These all evaluated under version 12.1. Why is that? And ...
asked by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 17 votes
answered by Devendra Kapadia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18617 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236843
Since we have soon historical conjunction of Jupiter and Saturn I have prepared code with visualization planet Jupiter and Saturn with moons. This code first been prepared for version 11.3 and with ...
asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237032
I am unable to obtain the numerical value of the derivative of the hypergeometric function.
Please note that the (2,4,0,0)
is the derivative with respect to the first and second
argument
asked by Sachin Kaushik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58727 7 votes
answered by Mariusz Iwaniuk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26828 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236980
I’m trying to solve the Schrödinger equation for the hydrogen atom without made the variable separation of the polar and radial coordinate. It is my test code to extrapolate to another system with its ...
asked by Jorge Castaño https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73029 7 votes
answered by Jorge Castaño https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73029 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236934
Sum[((-1)^(i + 1)*Binomial[n, i]*(n - i)!)/n!, {i, 1, n}]
This cause a Recursion problem.
As the comment said, If simplify the formula and then sum it, problem ...
asked by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236971
I have a function \(f(n)\) over \(n\in \mathbb {N}\). I want to know its maximum value over a very large domain, say \(n=1,2,3,4,...,10^6\). Is there a way to ask Mathematica to give me the maximum value of ...
asked by charmin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74550 6 votes
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237045
The surface is determined by this parametric equation
ParametricPlot3D[{Cos[],Sin[],z(2+ Cos[])},{,-Pi,Pi},{z,0,1}]
How to unfold the surface in Mathematica? ...
asked by expression https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7339 5 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=67521
I’m solving equations with many Cosines and Sines. And I want to convert all the Sines to
Cosines using trigonometric formulas such as cos(x)=sin(x+pi/2)
. How can I do
this?
asked by YongCheol Kwon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23041 3 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 51 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 66 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859
I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:
x1 y1 x2 y2 .....
asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937
Salacious title, but true story.
asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes
answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881
Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:
1) Continuous GIF animations with smallest possible number ...
asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 40 votes answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 54 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538
I want to get the following expression from Mathematica to LaTeX:
\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \]
I have tried to use inbuilt 'symbol'
character from the special ...
asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 19 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 27 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=627
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 148 votes
answered by ArgentoSapiens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=92 151 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236779
How can I do simple tests like determining if an integer is a power of 2? Mathematically, the result below should be True, and I understand why it doesn’t work on MMa, but how do I do this test ...
asked by Jerry Guern https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=20042 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=237042
I came upon an interesting problem. Suppose you have three vectors \(\psi =(a, b)\), \(\phi =(c,d)\) such that their components do not commute: \(ac\neq ca\), \(bd \neq db\) etc. (in general the vectors may ...
asked by geom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68502 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236932
I’m trying to write a Module that produces some arrows with custom Arrowhead shapes. However, I want the code external to the
asked by Wynne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36616 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236499
Christmas is around the corner! In preparation, consider the polynomial
f[x_,y_]:= 1/10 (4 - x^2 - 2 y^2)^2 + 1/2 (x^2 + y^2)
and define \(r=(f_x,f_y)\) using the ...
asked by fwgb https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44151 19 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236442
I need to produce the legend of a plot which encodes a color gradient together with a color gradient. In particular, I would like the image bellow to have the blueish edge faded and the redish solid:
asked by Marcelo Broinizi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53497 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236449
This is a cone with texture generated by PatternFilling in plane. The problem this texture mapping is not conformal. So my question is how to generated a pattern image which could suit a fixed height ...
asked by HyperGroups https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6648 5 votes
answered by cvgmt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72111 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236625
I have a system of ODEs which I’d like to solve with many (thousands) different initial conditions. In the net there are articles that CUDA can speed up such computations, but I haven’t found ...
asked by Andrew https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=306 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236558
I’ve been trying to use the function ThermodynamicData, and it is going fine when I try to calculate properties such as Enthalpy or Entropy or even phase as a ...
asked by Igor Stravinsky https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35043 5 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236526
I have two lists:
asked by Gregorio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75996 5 votes
answered by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236306
cuboids = Table[Cuboid @@ (pts = RandomReal[100, {2, 3}]), {i, 10000}]; Method1:
asked by HyperGroups https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6648 5 votes
answered by chyanog https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2090 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=13277
At the moment I am trying to construct a bifurcation diagram of the iterative function \(f(x)=\) \(ax-1.1975x^3\). I’ve scoured the internet for pre-made bifurcation diagrams and found many (mostly of the ...
asked by Mel https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3249 27 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 47 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 473 votes answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 285 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase ...
asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 17 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 33 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982
Here is a start.
MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 57 votes
answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 73 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043
Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...
asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes
answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=78451
I want to plot the following function:
\[\int \left (\frac {\Gamma (x+1)}{2}-\frac {\Gamma (x-1)}{2}\right ) \, dx\]
asked by Anixx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=651 4 votes
answered by k_v https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24727 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66273 I’m trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example,
asked by Matthew Brunetti https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22304 39 votes
answered by SquareOne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19960 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236606
I am rather new to Mathematica and I tried to find a solution for my Problem on my own, also looking through this site and the suggested Similar Questions, but I at least could not make out that my ...
asked by n00bBoi1 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76302 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236532
I am solving the following iterative equation to calculate Tf and Cp as a function of temperature:
An initial attempt for a ...
asked by John https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72940 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236345
I have a package which contains two subpackages: one ("`MOTSimulator`MOTGenerator")
which generates a systems of differential equations of the form
asked by crich https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76216 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235971
I have three function \(f(x)=x^x\), \(g(x)=\ln (x)^{\ln (x)}\), \(h(x)=\ln (x)^2\) and I want to find (numerically) \(C\) the center of the circle tangent to the three curves.
I think that one way is to find ...
asked by Domenico Modica https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76121 14 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236138
Why does Mathematica give me the function domain of \[f(x)=(2x-3)^{\frac {1}{5}}-(2x+1)^{\frac {1}{5}}-(x - 3)^{\frac {1}{5}}\] as \(x\geq 3\)? I used this command:
asked by Ramez Hindi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76160 7 votes
answered by Roderic https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=76085 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236149
Bug introduced in 4.2 or 5.0, persisting through 12.2.0.
Note: this is a repost of my OP on math.SE. I am posting it here because multiple users with different Mathematica versions have given me the ...
asked by Klangen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49819 7 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235911
Is there a way to get the tooltip to appear for parts of a string?
asked by user13892 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13892 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236188
I come from before the times of symbolic tensors in Mathematica, and am used to working with concrete tensors and custom commands to contract them using Transpose, Dot, etc. I recently realized that ...
asked by Stijn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69486 6 votes
answered by jose https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10552 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236161
I was trying to draw the following logo of an atom using Mathematica, but I could only figure out how to draw intersecting ellipses, not a nice logo like below. Do you have any idea? And is ...
asked by Saeid https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35814 6 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236077
Bug introduced in 4.1 or earlier and persisting through 12.2.0. or later
To the problem below, I get four independent, incomplete solutions, three in terms of ...
asked by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 6 votes
answered by Akku14 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34287 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219629
I’m trying to get some rays to bounce in a circle. But I want to be able to control the reflections, i.e. the direction the rays bounce in the circle. I have a MWE below, and it is severely limited by ...
asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 31 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 42 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66969
Here is a start. I’m looking for a nice way to draw it.
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 24 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19076
I’m trying to plot a function of the form \(z(r,\theta )\) where \(r \in [0, R]\) for a finite R, \(\theta \in [0,2\pi [\), and z is the third coordinate, a function of the first two. I couldn’t find anything ...
asked by Learning is a mess https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5643 18 votes
answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34073
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 42 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 64 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=50718
When importing a data file what are the comment symbols for Mathematica? That is, given a file like this
blabla bulbul 1 2 6 54 7 ...
what symbol do I have ...
asked by MaxJ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=14687 20 votes
answered by george2079 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2079 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586
I am trying to use the Export command to convert a list of plots into a *.gif
file,
and the command runs and executes well, but I can’t find the file! Where is it
...
asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236085
I’ve been struggling with one problem. I have a classic matrix in this example 12x4 such as:
matrix = Table[i, {i, 12}, {4}]
asked by Jakub Petrj https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75456 2 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235851
I am running into a very weird bug where setting $MinPrecision
to some value (in this case
200 has a very different and ...
asked by Kvothe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45020 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=236119
Somewhere in the following code there is a bug. The result should not be zero!
FunctionExpand@HankelTransform[Sqrt[r] Cos[r], r, k, 1/2]
I think the answer should ...
asked by SolutionExists https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70331 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235681
This may have a duplicate but I have spent some time looking and can’t find it. I have
experimental data in the form of { {x1, y1, z1}, {x2, y2, z2}...}
I wish to interpolate
it so my thoughts turned ...
asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 10 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235495
I’m trying to construct a ’smooth’ function \(f : \mathbb {R}^2 \longrightarrow [0,1]\) such that all level sets \[\{ x | f(x)=y\}\] are circles in a way that \(f\) looks like the ’Leaning Tower of Pisa’.
asked by darksun https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75863 10 votes
answered by fwgb https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44151 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235390
How can I ingest Mathematica / WL benchmark results posted at Mathematica Stack Exchange (MSE), like the ones posted here? Assumptions:
There are multiple answers with benchmarks posted
asked by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 10 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235524
I have the 3D coordinates for a set of points. I want to construct the convex polyhedron with those points as vertices.
I know I can use functions like DelaunayMesh
asked by Dennis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69969 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235403
Interpolation can make an InterpolatingFunction periodic with the option ...
asked by Chris K https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6358 8 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235711
I am trying to program a clock, I have the face I want and the hands but I can not seem to put them together so they work.....
asked by Struggling Student https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75041 7 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235413
I would like to replicate this ellipse, but with a right-angled triangle (with smooth/rounded corners). The formula for this ellipse:
asked by nightcape https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75304 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 180 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388
I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I’d also like the x-axis label to be in the middle of the x-axis rather than ...
asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 15 votes
answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2334
Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ...
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 145 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 119 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=850
Is there some way to do this other than going to Evaluation -> Quit kernel
and firing a
new one up?
asked by niklasfi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82 97 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 95 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19035
I asked Mathematica to compute the following
Solve[c (1-x)^2-x^(1/4) == 0, x]
and it returned this:
x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4
asked by ronanymous https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5730 38 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 64 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7142
When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 134 votes
answered by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 154 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3345
How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 86 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235678
I tried to use the Arnoldi method to get the smallest eigenvalue and corresponding eigenstate for large matrix. However, Arnoldi did not give me the desired result:
asked by lol https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40838 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235391
(This is part 2 of my earlier question, Can I overload Part for specific heads (a la overloaded array subscripting)?, which was well-answered as asked.)
Overview: My goal is to create a custom object -...
asked by Josh Helzer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75893 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=235775
I have following code. The function TraceSystem is to take partial trace of matrix and I think this part is fine. The main code is below in dd and I think the main problem is in here for Eigenvector. ...
asked by lol https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=40838 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234780
I am wondering if there is a simple way to define a structured 3D mesh (inclusion) like e.g. that and surround it with a corse and unstructured Matrix. It should be possible to refine both more or ...
asked by Max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68812 15 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234653
I’m trying to achieve a jelly / water surface effect. I’d like it to be a bit smoother. Here I am taking a triangulated rectangle and perturbing all points by a little random noise for each frame. ...
asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 14 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234564
Can Mathematica edit mp3 tags? I have a set of files and I’d like to batch process artist, album title, etc. I know other tools exist; I wonder if Mathematica can do it.
asked by GregH https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4393 11 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234866
Problem: when I draw a rectangle and put a coloured edge around it, the displayed edge is centred along the nominal edge and if it follows the same course as one of the axes then it does not show up. ...
asked by ruffle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59886 7 votes
answered by Brett Champion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234836
I have the following matrix \(M\):
\begin{bmatrix} P & p & 0 & 0 \\ pe_1 & Pe_1 & \sqrt{P^2 - p^2}q_1 & \sqrt{P^2 - p^2}r_1 \\ pe_2 & Pe_2 & \sqrt{P^2 - p^2}q_2 & \end{bmatrix}
asked by Anson Bdo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75764 7 votes
answered by LouisB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22158 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234931
Given a dataset as such
If "letter" is the header that is chosen, how do I convert it into an indexed dataset / association-of-associations? i.e. How do ...
asked by IntroductionToProbability https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60568 6 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234729
I want to put n equally spaced points on a circle and automatically draw chords from all points to a fixed point preferably P(0,0). I have managed to draw the points and the circle so far with
asked by Guy Foxx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75736 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180
Say I have a list x={2,4,6,8,10}
and I want to find out the positions of the elements that
are greater than 7.
asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 67 votes
answered by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 63 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544
Is there a way to find a limit of a multivariable function, like
\[\lim _{(x,y)\to (0,0)} f(x,y)\] with Mathematica?
When \(f\) is continuous, we can use \[\lim _{(x,y)\to (0,0)} f(x,y)=\lim _{(x,0)}\]
asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 31 votes
answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 42 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2116
According to the Mathematica help:
Round rounds numbers of the form x.5 toward the nearest even integer.
For example:
Round[{0.5, 1.5, 2.5, 3.5, 4.5}]
gives
asked by wxffles https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=427 82 votes
answered by Per Alexandersson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=488 50 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219629
I’m trying to get some rays to bounce in a circle. But I want to be able to control the reflections, i.e. the direction the rays bounce in the circle. I have a MWE below, and it is severely limited by ...
asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 31 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 42 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11982
I have some code that looks like
Table[ a = 1; b = {2, 3} c = i;, {i, 2} ]
which gives an error: Set::write: Tag Times in c {2,3} is Protected....
asked by dearN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=204 29 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 35 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=194384
In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ]
which
allowed it rapidly compose code that could solve problems simple to complex,
...
asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 52 votes
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 38 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043
Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...
asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes
answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234703
I am constructing matrices whose elements are lists themselves (of varying length), and am (re)setting the entries of these matrices using among others the "All" command. It seems that in ...
asked by Stijn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69486 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234749
I’m trying to reproduce the magneto-hydrodynamic flow studied here using the nonlinear FEM functionality, and have been having trouble implementing the Neumann boundary conditions. Pardon the long ...
asked by George Varnavides https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41179 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234577
I want to create an image in a cellular automata, more specifically an image of an object, like a turtle for example. I found this article online, and i am trying to replicate the results for growing ...
asked by Joana Bugalho https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75694 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234240
{5, 10, 3, 8, 9, 8, 8, 4, 1, 7}
let maxsum=20
, then I get ...
asked by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234373
I want to plot a function over a large range of \(x\). The problem is that for very large \(x\), even increasing PlotPoint to \(5\times 10^6\) and MaxRecursion 15, it does not give the whole result. But I ...
asked by charmin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74550 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234344
Each week I import a dataset, and every week the dataset differs in length (the number of records). After the import I need to do some transformations. One of these transformations is the ReplaceAll.
asked by Michiel van Mens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9590 7 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234143
Take a list with repetitions, say {a, a, b, c}
, and some permutation thereof, say
{c, a, b, a}
. I want to know which ...
asked by AccidentalFourierTransform https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34893 7 votes
answered by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234462
Consider the following:
g = RandomGraph[WattsStrogatzGraphDistribution[1000, 0.1, 5]] comm = FindGraphPartition[g, 2]; CommunityGraphPlot[g, comm]
asked by Caitlin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74961 5 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234302
Imagine I have a list of integers \(l=\{l_1,l_2,...,l_{50}\}\), say, for example
l = RandomInteger[10, 50]
and I want to find how many ways there are of summing ...
asked by sam wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=64001 5 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234154
Occasionally when I scrape images from a webpage, such as:
Import["https://www.freeart.com/gallery/m/mondrian/mondrian.html", "Images"]
only a ...
asked by David G. Stork https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9735 5 votes
answered by Rohit Namjoshi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58370 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388
I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I’d also like the x-axis label to be in the middle of the x-axis rather than ...
asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 15 votes
answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336
I am wondering how to implement the multi-peak detecting and fitting in Mathematica.
Following is an example of fitting the data using three peaks (such that the
data ~ peak1 + peak2 + peak3
). The ...
asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 55 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 55 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361
'Tis the season...
And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.
What is your best code for generating ...
asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573
I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...
asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes
answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4454
I’ve seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
asked by sblom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=178 122 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 85 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043
Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...
asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes
answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184
I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...
asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234502
I have \(d/2\)-dimensional variables \(a,b\) jointly distributed as Gaussian(\(\mu ,\Sigma \)) in \(d\) dimensions, and need to solve the following equation for \(X\) \[E[ab^TXab^T]=Y\] This is equivalent to ...
asked by Yaroslav Bulatov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=217 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234260
I’m trying to use the RunProcess function to run docker on Mac OS using Mathematica. But there is a problem:
asked by Wei Li https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75601 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234324
I use this code over the domain \(x\in (0,300)\)
asked by charmin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74550 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233846
This may be related to How to discretize a BezierCurve?, but this question deals with BSplineCurves with specific SplineWeights, ...
asked by robjohn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=232 10 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233804
I may have a solution but it is not slick! See below Doing numerical calculations with functions that use units can be very slow. I would like to have a function or operator that can turn my functions ...
asked by c186282 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4515 6 votes
answered by march https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29734 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=234036
I am trying to generate this type of graphic:
see Fig.1a
from https://arxiv.org/abs/0905.3587. This process is associated with two
transition matrices
asked by AG1123 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36275 6 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233877
Building neural nets in the WL is great. I was in the process of rewriting a previous GAN of mine in the WL to see if I can get better performance, and was surprised to find that the standard ...
asked by BBirdsell https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49805 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233863
We can construct a base-centered tetragonal unit cell by: LatticeData["CenteredTetragonal", "Image"]
But how can we construct a lattice by
asked by Inzo Babaria https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=33967 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233816
Bug introduced in 12.0 and persisting in 12.1.1
I want to change the plot markers of the data points in QuantilePlot. This seems pretty straightforward:
asked by Q.P. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27119 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233767
I want to split a large ordered list into consecutive non-overlapping sub-lists, such that all elements are within an interval from the first member of the sub-list . For example:
asked by Oleg https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75470 6 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=136974
My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.
asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 73 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 97 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2334
Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ...
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 145 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 119 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8885
How can I draw the 5 interlocking Olympic rings with Mathematica? (SVG version) Edit
Hard choice, but some pretty cool answers here. I didn’t have 3D answers in mind when I posted the question, but ...
asked by Mike Honeychurch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=77 44 votes
answered by cormullion https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506
I am wondering what is the correct function in Mathematica to plot the true impulse
function, better known as the DiracDelta[]
function. When using this inside of a
...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39003
I need to apply Van Gogh’s stroke brush effect to a random image Take the following image as an example:
Thank you so much if you could help!
asked by user10495 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10495 34 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538
I want to get the following expression from Mathematica to LaTeX:
\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \]
I have tried to use inbuilt ’symbol’ character from the special ...
asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 19 votes answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 27 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819
In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233931
Does anyone know if its possible to plot a confidence band in QuantilePlot? I haven’t been able to find any documentation for this, or a previous example on here.
asked by Q.P. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27119 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233823
It is well-known that \(e^{-1/x}\sim o(x^n)\) as \(x\to 0^+\) for any \(n\in \mathbb {N}\), thus if I do an asymptotic expansion for a function, say \(f=1/(1-x)+e^{-1/x}\) as \(x\to 0^+\), I expect to receive an ...
asked by user142288 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59534 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233726
Consider a system of equations
asked by John Taylor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41058 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233409
Is it possible to make a dynamic graph with an ability to drag vertices? In other words let vertices behave like Locators and change its ...
asked by swish https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2490 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233503
I have a number of val = 0.000015783 which represents a current value in Amps. I want to display it with 3 significant digits and with SI prefixes instead of the ...
asked by tobalt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27818 7 votes
answered by creidhne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41569 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233388
I was profiling some code and I am trying to understand what the results mean. Suppose we have the very idiomatic,
asked by ITA https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42145 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233677
I really love the flexibility of Mathematica: there are several ways to perform one task. However, to get the performance of the intense numeric calculation, it can ...
asked by Nam Nguyen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1712 6 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233637
In general, to define a function, we often use f[x_]
. Another way is to use pure function (full
form and shorthand). I want to test the performance of these ...
asked by Nam Nguyen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1712 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233665
Why number sign "#"
(known as hashtag symbol on social media) or at sign "@"
are not
consistent with the ...
asked by azerbajdzan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53172 6 votes
answered by creidhne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41569 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233340
I would like to solve the following: given \(t\mapsto \sigma (t)\) and \(E>0\), \(\sigma _y>0\), find \(\epsilon \) such that:
asked by anderstood https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18767 5 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=143691
Deep convolutional neural networks are very good at computer vision related tasks. Optical Character Recognition (OCR) is one important branch of computer vision. In fact, the convolution neural ...
asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 87 votes
answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 98 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11868
Why I get the error below with this code:
asked by Aurelius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1669 10 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139
In Wolfram Mathematica the function Fourier has the following declaration
Fourier[list]
And after a list is given to the ...
asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes
answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
asked by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 553 votes
answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 486 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895
I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes,...
asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 40 votes
answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=198839
https://blog.stephenwolfram.com/2019/05/launching-today-free-wolfram-engine-for-developers/
http://www.wolfram.com/engine/
The Free Wolfram Engine for Developers is available for pre-production ...
asked by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 63 votes
answered by Alexey Golyshev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23402 53 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3458
Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 42 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 29 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233672
Consider a function derivative[x_]:=D[Sin[x],x]
When calling it with some argument, like derivative[2]
, instead of \(\cos (x)\) it gives me \(\partial _{2}\sin (2)\). Is
...
asked by John Taylor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41058 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233470
I am trying to initialize a 48600 x 48600
packed array from a sparse matrix and a diagonal
matrix in Mathematica 8. If S1 is a sparsearray of that size then and S2 is list of 48600
length, then I am ...
asked by Roopayan Ghosh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54433 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233669
I can’t find any explanation about the details of the real computation, please anybody knows?
asked by pablo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61453 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233050
I found this image on the Internet and it is very beautiful. How can I reproduce it? The ideal would be to be able to control the colors of the outside as well as the center.
asked by Susana https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37778 12 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232976
Torque-free Euler equations experiment seen in low gravity of Russian spacecraft is modelled here with a view to see its tumbling motion around the intermediate axis \(\omega _2\) rotation. However its ...
asked by Narasimham https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19067 10 votes
answered by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233096
A fun combinatoric puzzle that’s popped up in my work that I think would be cute to have a Mathematica solution to, if anyone wants to give it a go. It’s basically a ladder climbing/descending problem ...
asked by b3m2a1 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38205 8 votes
answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233206
If I have the result
asked by GlomGive https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75305 7 votes
answered by wuyudi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68689 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232975
To write a mesher that closes a mesh surface using an implied surface from a boundary spline curve and mesh generated using DiscreteGraphics, I need to identify the Vertices and Lines around the edges ...
asked by mh2000 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57215 7 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233092
I want to extract the edge points from a text image and use ListPlot[points] to visualize those points:
I tried to used ...
asked by vito https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30288 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232960
Playing with integers I looked for a way of finding, let’s say, \(4\)-digits positive integers such that \(a,b,a+b\) had the same digits, like \[1089 + 8019 = 9108\] I am a newbie and I used this function
asked by Raffaele https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49764 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
asked by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 553 votes
answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 486 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14160
I’m trying to plot a phase portrait for the differential equation \[x'' - (1 - x^2) x' + x = 0.5 \cos (1.1 t)\,.\] The primes are derivatives with respect to \(t\). I’ve reduced this second order ODE to ...
asked by covertbob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4528 38 votes
answered by David Slater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1746 33 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=35653
In this example, how can I put the legend inside the graph? Currently, when I save the graph, only the graph is saved, not the legend.
asked by Mika Ike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6543 42 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 38 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293
I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,
\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)
where U(x) is some potential and Ei is the ...
asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 48 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...
asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 616 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 474 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704
Wolfram|Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica ...
asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting ...
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233105
Is there a way to get the equations of motion (eom) of a scalar field from a Lagrangian in a perturbed FLRW metric? I want to perturb the field as well as the metric to 1st order. What I did so far:
asked by kalle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68748 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233100
Background The box-formmating behavior is affected by the downvalues of the symbol MakeBoxes. But the formatting behavior is not exactly ...
asked by asd1dsa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72876 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=233287
To get the color at a 2D point in Graphics you can Rasterize it and look up the pixel value, but not for ...
asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231660
Since this question was not answered, I would like to ask again with some additional information. I have a trading chart saved as chart1 as follows.
asked by DLT https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54107 9 votes
answered by Lukas Lang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36508 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231695 Given
t1 = {{1, 2}, {3, 4}}; t2 = {{a, b, c}, {e, f}};
I want to add in succession elements of list 2 to list 1 to get:
asked by user57467 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57467 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231523
Although Undo has been around since version 10 (before my time) I’ve noticed that sometimes it works just fine up to the moment of the last ...
asked by Jules Manson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37721 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231588
I am trying to solve heat equation on a cylinder whose ends are thermally insulated and its circular face is exposed to convection. Therefore I have Neumann boundary condition on all faces of the ...
asked by Deep https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44615 7 votes
answered by yawnoc https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72028 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232789
I have manged to turn an image into a RawBoxes expression. How do I turn in back into something I can use in Graphics In ...
asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 6 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232809
I have the following datas:
I want to find mean age by using following formula,
Any way to do this in general in Mathematica easily.
asked by Jasmine https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73364 6 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232784
On Mathematica 12.1.1, Windows 10. When Suggestions bar is active, entering and evaluating the following crashes the Kernel.
asked by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 180 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 60 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=85139
In Wolfram Mathematica the function Fourier has the following declaration
Fourier[list]
And after a list is given to the ...
asked by user253956 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29958 27 votes
answered by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573
I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...
asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes
answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=136974
My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.
examples
asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 72 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 95 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361
’Tis the season...
And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.
What is your best code for generating ...
asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306
I have a complex expression with real positive variables only.
Mathematica Input Style:
asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 33 votes
answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 52 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231540
I have a text file which is a list of numbers and would like to pass each number in the list as input to a Mathematica function. For example, my text might contain [2, 1, 4], and I would like to pass ...
asked by Joshua Steier https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75099 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=231528
The form of the second order Runge Kutta formula is as follows(the following is from page 287 of this book):
asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=232859 I have an expression that I would like to take limits of but not in a conventional sense. Take for example, an expression like
This expression involves intermediate variables
asked by epsilonD3LT4 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75082 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230854
If I have a table of data and I want to do a specific operation on say the third column, I usually do something like this:
asked by Q.P. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27119 11 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230971
At the moment I use Length[ DeleteDuplicates[ array ] ] == 1
to check whether an
array is constant, but I’m not sure whether this is optimal. What would be the
...
asked by Gert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27889 11 votes
answered by Sjoerd Smit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43522 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230749
The following puzzle appears in The House of da Vinci II and I thought it might be interesting to tackle in Mathematica:
There are numbers marked on four rotating cylinders. These numbers must add up ...
asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230988
I’m looking for the shortest (in terms of characters) code snippet to make an n-square checkerboard. Here’s my first try (comes in at 72 characters):
asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230725
There is a 2D Pi
I successed transformed it to 3D.
asked by partida https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=15961 7 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230717
I want to replace the variable x in the result, not x in unrelated x[i]
asked by A little mouse on the pampas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230864
How to build a table that counts how many times each element in mainlist occurs in lst1, lst2, lst3, lst4 and which lst1, lst2, lst3, lst4 contains that element. For example, in mainlist, element ...
asked by PRG https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42700 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19035
I asked Mathematica to compute the following
Solve[c (1-x)^2-x^(1/4) == 0, x] and it returned this: x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 ...
asked by ronanymous https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5730 37 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 64 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
asked by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 550 votes
answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 484 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11982
I have some code that looks like
Table[ a = 1; b = {2, 3} c = i;, {i, 2} ] which gives an error: Set::write: Tag Times in c {2,3} is Protected....
asked by dearN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=204 28 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 35 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704
Wolfram|Alpha has a whole collection of parametric curves that create images of famous
people. To see them, enter WolframAlpha["person curve"]
into a Mathematica
...
asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=92931
Bug caused by paclet update and fixed by paclet update.
I updated to Windows 10 and have been running Mathematica fine on it for over a month. For some reason, it has just stopped working. I don’t ...
asked by mitcheljh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6783 80 votes
answered by ilian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=145 101 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306
I have a complex expression with real positive variables only.
Mathematica Input Style:
asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 33 votes
answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 52 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase ...
asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 15 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230846
How can I simplify the following equation with Mathematica assuming z!=0
? I have the
following code:
asked by Franz Ferdinand https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74882 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230943
Using the problem from my previous question link. For each n, that is n= \(10^3\) to \(10^6\) with a ten-fold increase, how do I use Chebyshev Bias to display the number of primes (which are in the ...
asked by complab56 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74866 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230784
This is my code:
asked by S.J.E. Huisman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74858 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230366
The Lotka-McKendrick model is a demographic model that represents the way a population changes over time due to fertility and mortality. For an age-specific population density \( u(a, t) \), and a total ...
asked by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 12 votes
answered by Chris K https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6358 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230429
I’m a newbie with Mathematica, I know it’s a basic answer, but I can’t solve the problem on my own. I have the following equation reflecting insect aggregation at low population densities (taken from ...
asked by Vefhug https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74729 10 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 17 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230622
I need to improve a pattern or switch an approach. It is best described by an example For a hierarchy/order given by a list e.g.:
order = {1, 2, 3}
and a list:
asked by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 9 votes
answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230484
Background Let’s say I want information (e.g. bulk modulus or space group) on an element
or chemical compound that isn’t available via e.g. ElementData[]
asked by Sterling https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61736 6 votes
answered by Sterling https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61736 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230383
I’m trying to solve a simple system of second order PDEs with Mathematica 11.1. Here is the system:
asked by C. B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74734 6 votes
answered by bbgodfrey https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1063 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230650
My mind is a bit cloudy and I can’t quite pinpoint the pattern here that will allow me to write an elegant piece of code to build the following symmetric matrix of for a given size ...
asked by QuantumDot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2048 5 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230613
I have a section in my notebook devoted to unit testing, since I’m not comfortable to use the built-in system. I’d like to evaluate the entire section by button click. But I get lost in the notebook ...
asked by infinitezero https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=31036 5 votes
answered by Kuba https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5478 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6669
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 56 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 34 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598
For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).
I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...
asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 43 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=15023
The basic multivariable Taylor expansion formula around a point is as follows:
\[ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac {1}{2!}(\mathbf a \cdot \nabla ) \]
asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 58 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 65 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over ...
asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 615 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 474 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222184
I am interested in benchmarking numerical integration methods and am trying to develop a wider set of difficult multivariate examples. For my particular methods, I only want to look at non-negative-...
asked by ben18785 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19278 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66969
Here is a start. I’m looking for a nice way to draw it.
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 24 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=148
Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?
asked by Cydonia7 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44 125 votes
answered by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 105 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230550
I am trying to solve the equilibrium equation \(\text {DIV } \mathbf P(\textbf {u}(x,y)) = \mathbf {f}\), where \(\mathbf P\) is the stress tensor defined by \[ \mathbf P = \mathbf F + (1-\det \mathbf F) \] asked by rmk236 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74782 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230520
I am trying to solve something like Fick’s Law using NDSolve
\[\frac {\partial \varphi }{\partial t}=\frac {\partial ^2 \varphi }{\partial r^2}+F(r,t)\] Subject to a ...
asked by UranylTrioxide https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74775 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230425
I have written the following piece of code:
asked by Mr. Mister https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74745 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230017
I am looking to recreate the following image from this reference as
using Mathematica’s Polygon documentation under "Applications" as a starting point. I want to eventually use Mathematica ...
asked by C. Fuhrman https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60593 10 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230018
I recently upgraded from Mathematica 6 to the most recent version. In my new version the Position function returns strange results that were not present in the old ...
asked by Peter https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74626 8 votes
answered by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229973
I recently upgraded from Mathematica 11 to Mathematica 12.1.0.0 . I understand there were some UI changes to accommodate high resolution monitors. I’m not sure if this issue is related to that. I am ...
asked by user3556814 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74618 8 votes
answered by Piotr Wendykier https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9239 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230060
I have a image of 1000 x 1000
pixels of which I have made 5 x 5
partitions. After that I am
looking for a way to count number of color pixels in each partition. Thanks in advance for
help.
asked by Atique Khan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59972 7 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230082
Define the following three vectors:
a = {0., 0., 0.}; b = {-0.5`, 0.4330127018922193`, 0.25`}; c = {-0.5`, 0.`, 0.`};
Note that the distance from a to c is the ...
asked by abwatson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1709 7 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230145
BarChart seems to read the uncertainty in elements the other way around. The object:
Around[5, {1, 10}]
is evaluated as . However, when you use it in a BarChart, the
uncertainties are swapped:
asked by Luis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24933 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230013
I just started working with Mathematica and am toying with pattern matching. There may be something obvious I’m missing in this, but I can’t figure it out by myself. I want to write down a function ...
asked by ppln https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69266 6 votes
answered by eyorble https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52935 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859
I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:
x1 y1 x2 y2 .....
asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 30 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 47 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895
I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes,...
asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 38 votes
answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18419
Mathematica 9.0 looks a bit fuzzy on the retina screen, how can I increase the resolution? Here another screenshot showing a direct comparison between the browser and Mathematica
asked by Tom Wellington https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2437 44 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=136974
My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.
examples
asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 71 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 95 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39003
I need to apply Van Gogh’s stroke brush effect to a random image Take the following image as an example:
Thank you so much if you could help!
asked by user10495 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10495 34 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32293
I’m trying to get the eigenvalues of a one dimensional time-independent Schrödinger equation,
\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)
where \(U(x)\) is some potential and Ei is the ...
asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 48 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180
Say I have a list x={2,4,6,8,10}
and I want to find out the positions of the elements that
are greater than 7.
asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 66 votes
answered by J. M.’s discontentment https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 63 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229962
I’m trying to use ImageCorrespondingPoints to register frames in a video sequence. Computational speed is an important consideration for the application I am ...
asked by Brady Hunt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9017 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=230052
How to code this expression in WolframAlpha. I am interested in how to code the second sum, because it contains a boolean expression: \[\sum _{i=1}^{100}{\sum _{j>n}}{x_{i}x_{j}}\]
asked by Andrey Stebenkov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74632 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229714
How can we use Mathematica to design an electronic implementation of an active filter?
asked by David Keith https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44700 19 votes
answered by David Keith https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44700 22 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229535
I would like to create a boundary mesh of the following ellipsoid, whose thickness is modulated along its long axis:
The surface parametrization I used for it is:
asked by Oscillon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13605 10 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229522
I have hundreds of Mathematica notebooks accumulated over the years, and I’d like to search over them. I’ve been using various versions of text search (grep, SilverSearcher, Spotlight), but there are ...
asked by Yaroslav Bulatov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=217 10 votes
answered by Chris Degnen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=363 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229703
Given the function \[f:v\mapsto \dfrac {v}{\|v\|},\] I would like to compute the derivative of \(f\), that is \(df(v)\). It is possible to derive it by hand, which leads to
asked by anderstood https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18767 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229853
I’ve been using Mathematica for some years, yet I’m befuddled by this statement:
GaborWavelet[6]["FourierFactor"]
It appears to give the center frequency ...
asked by Chris https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66733 7 votes
answered by Carl Woll https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45431 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229678
I have a dataset with 20 columns. For a analysis I need all columns except the columns 9 and 11. What I do is:
asked by Michiel van Mens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9590 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229502
As shown in many threads here (this, this, ...), Ticks is a valid option of BarLegend.
But it doesn’t seem to work well in this ...
asked by xiaohuamao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11125 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819
In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306
I have a complex expression with real positive variables only.
Mathematica Input Style:
asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 33 votes
answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 52 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763
When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)
asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes
answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting.
However, the result shown below is far from ...
asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 50 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 65 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=7545
I recently came across this video: Mathematically correct breakfast, which shows how a bagel can be neatly sliced into two identical linked halves. I’d like to try this with Mathematica. Here’s a ...
asked by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 62 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 76 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361
’Tis the season... And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.
What is your best code for generating ...
asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598
For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).
I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...
asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229778
I am trying to solve for what values of some variables make some expressions true; not exactly equations. For a toy example, I am trying to solve for all values of \(x\) that make \(4x\) an Integer.
asked by Matthew Crawford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51196 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229534
I am attempting to globalize the variables inside of a Manipulate expression for which my variables are also using interdependent controls. I have attempted to use
asked by Ryan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74490 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229660
this should be simple but I can’t get mathematica to simplify a radical or a set of radicals and express them in the traditional way for example by simplifying this
asked by BeTDa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72885 2 votes
answered by Daniel Huber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46318 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229164
makes it possible to call Python code from Mathematica. The Wolfram Client for Python makes it possible to call Mathematica from Python. When using ...
asked by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 8 votes
answered by Riccardo Di Virgilio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51868 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229242
I want to create an animation like this one: https://www.youtube.com/watch?v=rvzZmNW2_70 After googling I have found just below informations about this issue: https://twitter.com/bencbartlett/status/...
asked by Mustafa Kosem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74423 7 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229409
Given a list of 4-tuples as follows. data = Tuples[Range@6, 4]; I want to select any 4-tuples with two pairs of different twins, for example, as follows:
asked by Wissen Macht Frei https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229128
I need to display two y-values for a list of points. I tried doing this:
asked by Rodrigo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43431 6 votes
answered by LouisB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22158 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229239
I have a process that as part of it requires a certain probability query, specifically, given a multinomial distribution with f equiprobable categories and r trials, some specific category has a given ...
asked by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 5 votes
answered by JimB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19758 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229299
I am trying to create an image in which a rose flower image in a 3D space with axes labeled in UTF8! Labels don’t render correctly and not sure how to put the image at say the original of XYZ space.
asked by chikitin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74442 4 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229427
I have a problem with nested lists. For example, i have this list:
asked by aptmess https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58120 4 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34668
If you enter the following into Wolfram | Alpha, you get nice graphs:
graph 4 x^4 + y^2 = 2
How do you do this in Mathmatica? I realize that these are not
...
asked by Rollie https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10174 36 votes
answered by Timothy Wofford https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9391 38 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937
Salacious title, but true story.
asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes
answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19546
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The problem
asked by s.s.o https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=840 64 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 59 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=143691
Deep convolutional neural networks are very good at computer vision related tasks. Optical Character Recognition (OCR) is one important branch of computer vision.
In fact, the convolution neural ...
asked by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 87 votes
answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 98 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763
When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)
asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes
answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=36792
I need to play with a lot of powers such as 10^-3,1E-3
does not work for it. Is there any
short form for it?
asked by hhh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2000 59 votes
answered by Joe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44710 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18598
For my Calc III class, I need to find \(T(t), N(t)\), and \(B(t)\) for \(t=1, 2\), and \(-1\), given \(r(t)=\{t,t^2,t^3\}\).
I’ve got Mathematica, but I’ve never used it before and I’m not sure how to coerce ...
asked by a98 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5605 30 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229313
I am using FindClusters with the Method -> "KMedoids"
option. I am specifying a desired
number of clusters. It returns with many fewer than the desired number. Is there a way to
force it ...
asked by abwatson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1709 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229251
I wish to plot the following probability on Mathematica: \[ \pi =n\cdot \int _{-\infty }^{+\infty }\int _{-\infty }^{+\infty } \]
asked by Avocaddo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68764 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=229185
I would like to solve a system of differential equations and another euqtions conect to the system. For example:
asked by Slayz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74408 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228775
As a generalization of DeleteDuplicates, I want to delete duplicates from a list, but only after n number of duplicates. Say,
asked by azerbajdzan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53172 11 votes
answered by ciao https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11467 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228524
I have a closed curve. I am trying to enclose this closed curve with another closed curve, which looks identical in the shape of the first closed curve, but slightly bigger. How to do this?
asked by acoustics https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53981 10 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 17 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228738
I am trying to find a way (desirably simple and performance/speed optimized for larger graphs) to do the following :
Styling graph vertexes by glow-effect and its intensity depending on ...
asked by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 8 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228484
Running Quit is a core task repeated many times in any debugging/development cycle. Its efficiency is therefore important and yet in my set-up it is taking ...
asked by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 8 votes
answered by Ronald Monson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2249 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228579
Let's say I have a list {{1, 2, 3}, {4, 5}, ...}. I want to make the list look like {1, 2, 3, {4, 5}, ...}. I am doing this way:
asked by Arghya Datta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=51545 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228692
I find the following behavior using 12.0.0. (EDIT: I asked a friend to try it in 12.1.1 and he finds the same result.) Here is a system of coupled nonlinear PDEs that ...
asked by Will.Mo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49788 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228768
How to collect the common powers appearing in the following function using MATHEMATICA, such that if I input
(4 m^6)/((m - n)^2 (m + n)^4 (2m+n)^4)
then the ...
asked by Erosannin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73763 6 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819
In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting ...
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982
Here is a start.
MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 56 votes
answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 71 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34073
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 40 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 63 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=125043
Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...
asked by Sumit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8070 69 votes
answered by andre314 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5467 76 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=42359
Following is the equation: Need to solve for integer values of x,y when a,b lies between -1000 and 1000. Problem is to find the number of integer values of pair (x,y) that satisfy it.
asked by Sahil Sareen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12396 2 votes
answered by bill s https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1783 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14160
I’m trying to plot a phase portrait for the differential equation \[x'' - (1 - x^2) x' + x = 0.5 \cos (1.1 t)\,.\] The primes are derivatives with respect to \(t\). I’ve reduced this second order ODE to ...
asked by covertbob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4528 38 votes
answered by David Slater https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1746 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228496
I have documented the following issue with evaluating the Export function via J/Link: https://stackoverflow.com/questions/63390977/wolfram-mathematica-kernellink-export-function-not-working-via-jlink- ...
asked by Ceddaerrix https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74211 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228631
I am trying to put a custom arrowhead on an arrow I am drawing in a plot. My problem is that the (thick) line of the arrow is showing behind the arrow tip. So it seems like the arrowhead is aligned ...
asked by Bjoj https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36437 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228733
In the video of the link below, at 1:40 is said that the presentation can be controlled by a mobile device, how can I do that?
https://www.youtube.com/watch?v=GMHM_iUL_sU
asked by Daniel Rocha da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74279 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228295
I have just learned about the new function Splice from this answer. It turns out that this function used to have a completely different usage! (See below.) To me, this seems dangerous, to deprecate a ...
asked by march https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29734 14 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228320
Here is what I have tried first.
Thread[f["x", {"1", "2"}]] {f["x", "1"], f["x", "2"]}
But the weirdest thing happened when I ...
asked by kile https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=65814 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228363
I have a function of, say 4 arguments f[a,b,{c,e},d]
where some of the arguments are
lists. Given a list of triplets that are possible last-three-arguments to f I’d like to paste them
as arguments to ...
asked by ulvi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1714 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228088
I have a very long list of rules, and using this list of rules I want to see how some elements evolve as I successively apply the next rules on the previous rule.
Here is the simpler version of my ...
asked by Gummala Navneeth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66938 6 votes
answered by march https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29734 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228319
I’m interested in the periods of limit cycles of the Wilson-Cowan equations which have the form \[x'(t) = -x + S(ax(t) - by(t) +e)\] \[y'(t) = -y + S(cx(t) - dy(t) + f)\] where \[S(x) = 1 + \] ...
asked by Cheyne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74162 5 votes
answered by Chris K https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6358 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228423
I have a dataset consisting of points on the plane and a corresponding color. These colors divide the plane into a few distinct regions. I would like to make a plot or diagram that nicely shows this ...
asked by Cheyne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74162 5 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228278
I want to find the word "circle" and "circles" in the list.
list = {"circle" , "picircle" , "circles" }
The regex code I wrote which isn’t working:
asked by Aryan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73776 5 votes
answered by Natas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67431 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3242
For instance, is there some way I can say "let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ...
asked by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 63 votes
answered by Chip Hurst https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4346 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=109982
Here is a start.
MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 56 votes
answered by Martin Ender https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2305 71 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting some errors. Is there something wrong ...
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16108
I am not sure how to find out what all is included as curated data. For example, are the individual images of each of the 52 cards in a standard deck of playing cards included?
If not, is there a way ...
asked by JohnD https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1629 25 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=50718
When importing a data file what are the comment symbols for Mathematica? That is, given a file like this
blabla bulbul 1 2 6 54 7 ... ..
what symbol do I have to put in front of header lines so ...
asked by MaxJ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=14687 20 votes
answered by george2079 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2079 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=24169
I’m new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations.
For example in sphere’s case \(x^2+y^2+z^2=1\)
I tried to use Plot3D but it doesn’t ...
asked by German https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7145 7 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=17704
Wolfram|Alpha has a whole collection of parametric curves that create images of famous
people. To see them, enter WolframAlpha["person curve"]
into a Mathematica notebook,
or person curve into ...
asked by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228347
I have problems getting the Citation Management in Mathematica 12.0 to work. It does not work with either EndNote or BibTeX. To do a minimal example, I have the following BibTeX file (libra.bib) ...
asked by jaclea https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7911 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228257
I have a list T which contains 3 + 4*E^(2*Pi*I/3). Yet MemberQ[ T , 3 + 4*(-1)^(2/3) ] returns false. One can check for themselves with MemberQ[{3 + 4*E^(2*Pi*I/3)}, 3 + 4*(-1)^(2/3)]. It will return ...
asked by Descartes Before the Horse https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69355 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228403
I have a few image urls that I want to download async, how can we monitor progress of URLDownload? Example:
Monitor[ URLDownload[ WebImageSearch["dog", ...
asked by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227863
A functional square root of a function \(g\) is another function \(f\) such that \(g=f\circ f\). According to that article, there is a systematic approach to finding a functional square root that involves ...
asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 10 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227893
Bug introduced in 12.1 or earlier and persisting through 12.1.1 or later [CASE:4615361]
Note: A worse problem existed in 12.0 for inputs greater than 8 and of precisions less than 43.66; 12.1 fixed ...
asked by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 9 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227846
Sometimes the simplest things are the most difficult, I need to make a presentation, and I thought to do it in Mathematica, I wanted to do a demonstration too, well...this is the Rutherford’s equation
asked by Chris Schwenke https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=65367 9 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227869
@JimBelk
asked in Interpolating an Antiderivative how to find a numerical antiderivative. I
gave an answer that uses NDSolve with the default method for integrating \(y'=f(x,y)\). However for
...
asked by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 8 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227990
This is the a list of set.
data = {{"A"}, {"J"}, {"Q"}, {"G", "H"}, {"I", "O"}, {"B", "C", "E", ...
asked by partida https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=15961 6 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227996
If there are grammatical or terminological errors in the following description, please help correct:
In some problems, it is necessary to find out what minimum number of exchanges can change a list ...
asked by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 5 votes
answered by Hausdorff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73380 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227837
How do I get rid of the mesh in this contour plot?
ContourPlot[x^2 + y^2, {x, -10, 10}, {y, -10, 10}, Contours -> {1.0, 4.0, 10.5}, ContourStyle -> None, ContourShading -> ...
asked by QuantumDot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2048 5 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16881
Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:
1) Continuous GIF animations with smallest possible number ...
asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 39 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 53 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19035
I asked Mathematica to compute the following
Solve[c (1-x)^2-x^(1/4) == 0, x] and it returned this: x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 + 70 #1^4 c^4 - 56 #1^3 c^4 + 28 ...
asked by ronanymous https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5730 37 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 63 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 179 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 60 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819
In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 198 votes answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 257 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19859
I need to save data that Mathematica uses inside the Plot command. The format that I would like to have is:
x1 y1 x2 y2
i.e. basically, two columns, x and y (sorted, if possible) so that I ...
asked by molkee https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5097 29 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 62 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3561
In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?
f[x_] := (x^2 z)/((x^2 - y^2)^2 + 4 q^2 x^2) /. {y -> /15, z -> 1, q -> ...
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 56 votes
answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 76 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227756
It can be seen from the following relationship that matrix A and matrix B must be congruent matrices with each other:
A = {{1, 4, 4}, {5, 2, 2}, {3, 1, 3}}; B = EulerMatrix[{/4, 0, ...
asked by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 3 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=228028
Is it possible to get an analytical solution to the following problem? If so, how? \[a w^{(1,0)}(x,t)+b w^{(0,1)}(x,t)=p(x)+g w(x,t)\]
asked by Scott G https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=74062 1 vote
answered by Michael Seifert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27813 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=227812
Let's say we have GP[v],GM[v]: two noncommutative objects depending on the commutative variable v. << NC`; << NCAlgebra`; SetCommutative[v]; SetNonCommutative[GP, GM] NCCollect[ GM[v] ** ...
asked by Kawette https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60529 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226089 I put
{TensorProduct[{1, 0}, {0, 1}, {0, 1}, {0, 1}, {0, 1}]}/Sqrt[2]//MatrixForm and I got $$ \left( \begin{array}{cc} \left( \begin{array}{cc} \left( \begin{array}{cc} 0 & 0 \\ 0 & 0 \\
asked by Moeki https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73815 12 votes
answered by Suba Thomas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5998 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226334
Alright, so this is a question about the functional way to break a for/while loop. Since we’re on the Mathematica SE, I’m interested in the ways a Mathematica vet would handle this, however the ...
asked by dskeletov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34831 8 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226171
I am working with hexadecimal bytes but need to shift them into lists of binary bits for a few operations and then back again. For example, I would like C12B to turn into ...
asked by toothandsticks https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73837 8 votes
answered by Hausdorff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73380 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226128
V 12.1.1, starting a kernel, e.g. by entering wolframscript in the shell, takes an unexpectedly long time (~5 min, the time elapsed between pressing Enter and the showing-up of In[1] := ); but the ...
asked by https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12924 8 votes
answered by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226294
I have a list with all elements at the same level
{ {a, d}, {a, e}, {a, f}, {b, d}, {b, e}, {b, f}, {c, d}, {c, e}, {c, f}, {x, t}, {x, q} }
How can I transform this to a list of ...
asked by Martin Leung https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73880 7 votes
answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226316
Without any obvious reason Mathematica started to emit a beep after each evaluation, even when it is error free. Why is that, and how can I turn it off? I tried restarting Mathematica to no avail, and ...
asked by Jxx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68480 6 votes
answered by Ordinary users68 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226327
A Prony series is similar to a Fourier series but can have fewer terms. It takes the form \(\sum _{i=1}^{M} A_i e^{\sigma _i t} \cos \left (\omega _i t+\phi _i\right )\) Note that unlike Fourier series ...
asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4454
I’ve seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
asked by sblom https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=178 121 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 83 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19546
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The ...
asked by s.s.o https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=840 63 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 58 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5790
If we have two vectors, \(a\) and \(b\), how can I make Jacobian matrix automatically in Mathematica?
$$ a=\left( \begin{array}{c} x_1^3+2x_2^2 \\ 3x_1^4+7x_2 \end{array} \right);b=\left(
asked by George Mills https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1012 38 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 50 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=50718
When importing a data file what are the comment symbols for Mathematica? That is, given a file like this
blabla bulbul
1 2 6 54 7 ...
what symbol do I have to put in front of header lines so ...
asked by MaxJ https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=14687 20 votes
answered by george2079 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2079 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180
Say I have a list x=2,4,6,8,10 and I want to find out the positions of the elements that are greater than 7.
Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 65 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 62 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3345
How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):
RandomBlot[num_, opts___] := ...
asked by István Zachar https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=89 86 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39361
’Tis the season... And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.
What is your best code for generating ...
asked by Peltio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6745 140 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 181 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226081
I am trying to fill a vector starting from component 11 from another vector, I use this code:
Do[AppendTo[xp, x[[i + 10]]], {i, 1, 99982}]
How can I fill xp without using ‘AppendTo’?
asked by mattiav27 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8822 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226231
I am trying to solve a cubic equation using Mathematica of a rather complicated expression say \(f(r,\beta ,\theta )\) , and in terms of \(r\) the maximum degree term that appears is of degree \(3\) so I ...
asked by Wubba lubba dub dub https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70072 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=226130
I know how to use Select to generate a list of numbers which satisfy a certain condition. However, I am not sure how to do this for points (specifically 2-tuples) rather than numbers. What I am trying ...
asked by Descartes Before the Horse https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69355 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225711
When FiniteElement method is used, the differential equations will first be transformed to certain standard form (named as formal PDE in recent FEM document), and it turns out to be critical to check ...
asked by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 11 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225928
To calculate force acting on an airfoil we can use FEM with version 12 and over. Here we show an example with NACA2415. First we calculate mesh and potential flow:
ClearAll[NACA2415]; NACA2415[{m_, ...
asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 9 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225811
Yes I know there is no built in native function called SymbolQ (but JavaScript does). However could one be simulated to work for most cases? I often rely
on objectName[symbol] and makeRuleRow[symbol] ...
asked by Jules Manson https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37721 9 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225910
sample2 = "this is a test to find whether pi works for other words or not as well pi pi pi potatpi pineapple pi-neapple";
so sample2 is a string, and I want to search the word/substring ...
asked by Aryan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73776 8 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225941
Is there a way to change the coloring of the boxes that are generated by Animate or Manipulate? The color of what is gray by default.
Animate[ArrayPlot[CellularAutomaton[n, {{1}, 0}, {40, All}]], {n, ...
asked by thinkingdude https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73139 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225985
I have some data :
data={{1.01074, 0.964488}, {1.08552, 0.993067}, {1.07907, 1.01836}, {1.0477, 1.03695}, {1.07717, 1.07973}, {1.10243, 1.08195}, {1.12669, 1.09112}, {1.09405, 1.09319}, ...
asked by J.A https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58104 7 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225929
I have a list of replacements and some list they are acting on. However, some RHS of the replacements rules are identical (the LHS is not). I want to use those rules one after another (perhaps cycling ...
asked by Kvothe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45020 7 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388
I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I’d also like the x-axis label to be in the middle of the x-axis rather than ...
asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 15 votes
answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378
I’m visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something like:
Manipulate[ DensityPlot[ ...
asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 45 votes
answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=194384
In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ]
which
allowed it rapidly compose code that could solve problems simple to complex, based on my
requirements. Understand ...
asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 52 votes
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 38 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=207522
I just upgraded my macbook to 10.15 and could not open Mathematica 11. I am wondering are there any workarounds to use Mathematica 11 without upgrading to 12? Thank you!
asked by Jiang Xiang https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16218 27 votes
answered by Itai Seggev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4848 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544
Is there a way to find a limit of a multivariable function, like
\[\lim _{(x,y)\to (0,0)} f(x,y)\] with Mathematica?
When \(f\) is continuous, we can use \[\lim _{(x,y)\to (0,0)}\] ...
asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 31 votes
answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 42 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538
I want to get the following expression from Mathematica to LaTeX:
\begin{bmatrix} E_{\parallel} \\ E_{\perp} \end{bmatrix}
I have tried to use inbuilt ’symbol’ character from the special ...
asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 18 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 26 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225913
I was wondering if it is easy to see if a given expression evaluates to a real number in a given domain? Let e.g. \(f(x,y,z)\) be some function depending on three variables \(x,y,z\). I would like to know if ...
asked by CAF https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=30885 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225980
Generally the Argmax function returns one position, where a function is maximized. Is there a easy way to obtain a list of rules for all maximizer points?
asked by Daniel Rehsmann https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73792 1 vote
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225678
I just upgraded to v7.114 of AceFEM running on MacOS 10.15.5 and Mathematica 12.0.0.0. I was running v7.101 without a problem. AceGEN seems to work but all AceFEM code starts but does nothing. The ...
asked by Andrew https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73727 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225238
Problem For purely recreational purposes I would like to solve the Monty Hall problem with Mathematica using the function Probability (dedicated to the calculation of probabilities). About the Monty ...
asked by mlpo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11155 12 votes
answered by Sjoerd Smit https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43522 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225337
I’m trying to change the opacity of a line in a ListLinePlot for increasing x-value. E.g. the line should have opacity 1 at beginning and shade than down to opacity along the line. I want to take the ...
asked by piolio https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73660 10 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225360
I work with a complex dataset. The most simple form of this list looks like:
dat1 = {{a, b, c, {}}, {d, e, f, {1}}, {h, i, j, {2}}} I want to select the nested {} part. Cases[dat1, {___, {a_}} :> ...
asked by Michiel van Mens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9590 9 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225277
I want to write some code to simulate a damped oscillator that is just as fast as code written
using Numba's @njit
decorator. I’ve written the mathematica code and mine is 20-40x
slower than the ...
asked by Diffycue https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46327 9 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225540
I would expect more highly nested lists, being deeper and more complex than flatter lists, to take up more space (bytecount) and take more time and memory to operate on in general. Consider the ...
asked by Just Some Old Man https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12697 7 votes
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225186
I did a MatrixPlot of a set of values that range between 0 and 1. I got the following first plot with no problems:
As we can see from the legend, the values range between 0 and 1. Now, I am doing ...
asked by Naps https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73570 7 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225380
I’ve got an inequality of 10 non-negative parameters (arising from a 5x5
matrix) and
would like to verify whether it holds. I tried the following, which doesn’t seem to
work:
asked by Vicky https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73675 6 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895
I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes, I run into the following error:
asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 38 votes
answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573
I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...
asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes
answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11350
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over PlotLegends to have these ...
asked by Amatya https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2039 613 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 472 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16485
I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about "Power programming with Mathematica" ...
asked by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 158 votes
answered by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 233 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538
I want to get the following expression from Mathematica to LaTeX:
\begin{bmatrix} E_{\parallel} \\ E_{\perp} \end{bmatrix}
I have tried to use inbuilt ’symbol’ character from the special ...
asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 18 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 26 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19669
Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 164 votes
answered by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 234 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=4444
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
asked by Tianxiang Xiong https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1041 62 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225465
I’m trying to make a visualization of grid (representing magnetic states) and I want to include a meter that shows a variable calculated from the manipulate index
(of the form J1/J2 = (index)*0.1) so ...
asked by mike1994 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73104 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225436
All of the functions in How to create a progress bar?, the ProgressIndicator built-in and Monitoring lengthy computations estimate the completion time for implementation of operations that are ...
asked by thinkingdude https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73139 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225231
I am trying to create an uppertriangularized matrix of arbitrary size,max of the form
{{1,2,3,4,5},{0,1,2,3,4},{0,0,1,2,3},{0,0,0,1,2},{0,0,0,0,1}} using the code table = Table[mu^(j - 1) ...
asked by Z Ming Ma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70345 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224739
I am trying to use the FEMAddOns package to make a structured mesh with a hole and then extrude it. As a warm up example this worked nicely.
Needs["FEMAddOns`"] pts1 = Table[ 25. ( ...
asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 14 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225008
been going around in cirlces on this:
{1/3, 1, 0.22, 3, "v", 4} /. _?NumericQ -> "999"
Now I’m trying to replace everything that is not a number; is there a way to do this? ...
asked by CuriousDudeFromEgypt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66462 10 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224830
Imagine I want to model 2D cells moving in a tissue. Consider, as an example, Lloyd’s relaxation algorithm. Using VoronoiMesh I’m able to mimic some cell movement. Now, if I colour one of the cells in ...
asked by sam wolfe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=64001 9 votes
answered by TumbiSapichu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53229 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224907
I was working with mathematica and I need to use "Filling", however I notice that it doesn’t work when you have "small" numbers, for example if I make the following:
asked by Cruz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69573 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224987
Just check
i_: 0 | 1 // FullForm In v12.0 or earlier the output is Alternatives[Optional[Pattern[i, Blank[]], 0], 1] But in v12.1 the output becomes Optional[Pattern[i, Blank[]], Alternatives[0, ...
asked by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 9 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225071
Suppose I have the following StringReplace rule
StringReplace[st, {"a" -> "0", "OverBar[a]" -> "1", "b" -> "1",
asked by math https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72358 8 votes
answered by Suba Thomas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5998 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224874
I am trying to represent the image below in Mathematica and can’t seem to make it work. There doesn’t seem to be any constraint of type circle intersection in the documentation. I tried this:
asked by SorinS https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73427 8 votes
answered by SneezeFor16Min https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69875 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11868
Why I get the error below with this code:
Needs["VectorAnalysis`"] = 1000; g = 9.80665; = 0.001; p[x_, y_, z_, t_] = {x^2, Sqrt[y], -z, t^3}; f[x_, y_, z_, t_] = {-x^2, Sqrt[y]/2, z, t^2}; ...
asked by Aurelius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1669 10 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 462 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 279 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=14035
Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?
asked by Seyhmus Güngören https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4256 41 votes
answered by rm -rf https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 48 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180
Say I have a list x=2,4,6,8,10 and I want to find out the positions of the elements that are greater than 7.
Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 64 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 62 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=148
Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?
asked by Cydonia7 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44 125 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 105 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=208045
I’m just curious. My friend just told me that Mathematica is mostly for symbolic calculation and not efficient for Numerical computations. He told me that’s the reason most of the people don’t use ...
asked by Gummala Navneeth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66938 44 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 73 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224966
I was replacing some usages of Geometry‘ConvexHull2 with ConvexHullMesh and found one of my tests failing. It turned out the test asserted an incorrect expected result that agrees with the result of ...
asked by Vladimir Reshetnikov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7288 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224730
Obviously, Plus[a,b] is given by Mathematica but say I have a package and I want to name a function Plus[a,b]. How can I go about making a new function without overwriting the original function ...
asked by Brandon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73362 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=225023
I want to be able to use Simplify (or FullSimplify) to simplify expressions involving, for example, sums of integrals, for instance turning \[ \int _a^b f(x)\,dx + \int _b^c f(x)\,dx \] into \[ \int _a^c\] ...
asked by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224461
Bug introduced in 12.1.1
Since I upgraded to version 12.1.1 I am unable to use > (Shift+.)
. When I type Shift+
.
the cell that I am typing in converts to Python. What am I doing wrong?
Steps to ...
asked by wdacda https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27856 15 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224581
My attempt:
data = {{a, 3}, {b, 5}, {c, 2}}; output = Table[#[[1]], #[[2]]] & /@ data // Flatten {a, a, a, b, b, b, b, b, c, c}
asked by Too Fat Man No Neck https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 11 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224500
Given
t={{7, 13, 19}, {13, 25, 37}, {19, 37, 55}, {25, 49, 73}, {31, 61, 91}, {37, 73, 109}} I want to select those lists where all three numbers are primes, so I should get {{7, 13, 19}, {37, ...
asked by user57467 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57467 9 votes
answered by Pillsy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=531 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224314
I just have a simple problem. I have a list such that,
rep = { a1 -> b1, a2 -> b2, a3 -> b3}; I want to invert replace direction such that, { b1 -> a1, b2 -> a2, b3 -> a3}
asked by Saesun Kim https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=29998 8 votes
answered by PaulCommentary https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54458 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224269
I have a list of coordinates that make a near-parabolic graph, which I managed to fit and calculate the curvature. However, the curvature only outputs a equation. Is there any way to calculate the ...
asked by Char https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66040 8 votes
answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224276
There is a known expansion for the Dirac delta function in the interval \( (-1, 1) \) in terms of the Legendre polynomials as
$$\delta(x) = \sum_{k = 0}^{\infty} (-1)^k \frac{(4k + 1) (2k)!}{2^{2k + 1}
asked by Novice https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72595 7 votes
answered by yarchik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9469 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224511
I am trying to find out what methods/options are available for NDEigensystem and
descriptions of their use. Perusing the help, online Q&As
, Mathematica’s in-line autofill, etc.,
I’ve found a few, ...
asked by Eli Lansey https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9 6 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=35653
In this example, how can I put the legend inside the graph? Currently, when I save the graph, only the graph is saved, not the legend.
Expr1 = -2 p + 1 Expr2 = 2 p - 1 Expr3 = p - 1/2 Plot[{Expr1, ...
asked by Mika Ike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6543 41 votes
answered by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 35 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433
I am using this code to plot a graph, and I am trying to make the font of the legend bigger.
<<PlotLegends` ListLogLogPlot[{Sort[moby]}, PlotRange -> Full, Joined -> True,
asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26268
This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ...
asked by Murta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2266 194 votes
answered by halirutan https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=187 190 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763
When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)
asked by J.D’Almbert https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 8 votes
answered by Alexei Boulbitch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=627
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 145 votes
answered by ArgentoSapiens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=92 149 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 462 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 279 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=434
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
Sin[x]^2+Cos[x]^2==1 Sin[x]/Cos[x]==Tan[x]
asked by Prashant Bhate https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=99 30 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 37 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224477
So I have a DE which has no analytical solution and thus solved using NDSolve, involving some parameters like this:
solution=NDSolve[{b/z[t]^4+a z'[t]+z''[t]==0,z[0]==3,z'[0]==3},z,{t,0,5}]
I was ...
asked by t-smart https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53560 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224402
Given two matrices \(A\) and \(B\), their Binomial expansion is, in general, given by (see this page) \((A+B)^n = \sum \limits _{k=0, k=n[2]}^n \Bigg ( \sum \limits _{r=0}^k \binom {k}{r} A^r B^{k-r} \Bigg )\) ...
asked by Rob https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66809 1 vote
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224258
I plan to use a ZWO ASI planetary camera (USB connection) for astronomical photography and would like to control the image acquisition using Mathematica. The issue is that although I have installed ...
asked by Dave Baker https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73406 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223907
Given a list:
lis = {37.21, 37.21, 37.2, 44, 44, 44, 101, 101} What is a simple way to extract the second largest elements? In[]:= someFunction[lis] Out[]= {44, 44, 44}
asked by Conor Cosnett https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36681 14 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224062
I am going to buy a new powerful desktop that I will use to run finite element simulations using AceFEM. I found out that the new AMD Ryzen 9 3950X obtained more points in the CPU Passmark benchmark ...
asked by KratosMath https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53039 8 votes
answered by marko https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=48938 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223978
I found something interesting on this page (Generic contour smoothing with shading) that could help me improve my images. Unfortunately, they can only be used with graphics generated by the software ...
asked by LCarvalho https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=37895 8 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223899
I’m running Mathematica on a machine wtih 48 cores and 96 threads. I want to limit the
number of threads the computation can have access to. If I give LaunchKernels[1]
it
correctly launches a single ...
asked by Paolo Pani https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73287 8 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223943
I have the following convex hull.
P0={0,0,0}; P1={1,0,0}; P2={0,1,0}; P3={0,0,1}; ConvexHullMesh[{P0,P1,P2,P3}]
Now I want the region algebraically as equality of the convex hull generated, in ...
asked by Sumit Banik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71940 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223817
We want to find the zeros of a multi-dimensional function
f[x_, y_] = {x + 1/4 (-Cos[x] + Sin[y]), x - y - Sin[y]/4}
To find the zeros, we can initialize and show the iterates using FindRoot
asked by Moo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36141 7 votes
answered by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224140
In Wolfram Language, Import["file.wl"] can import external wolfram package, Is it reversible? Can I unimport some packages? In other means Unset all the Function, Variable which is Set when ...
asked by Audra Jacot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67051 6 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=87388
I need to change the position of my axes labels such that the y-axis label is in the middle and parallel to the y-axis. I’d also like the x-axis label to be in the middle of the x-axis rather than ...
asked by John_dydx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7849 15 votes
answered by Virgil https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27697 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586
I am trying to use the Export command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can’t find the file! Where is it supposed to go? Did it even work?
asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66273
I’m trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example,
u[x_] := Sqrt[2/L] * Sin[Pi * n * x / L]
and then ...
asked by Matthew Brunetti https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22304 36 votes
answered by SquareOne https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19960 22 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3561
In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?
f[x_] := (x^2 z)/((x^2 - y^2)^2 + 4 q^2 x^2) /. {y -> /15, z -> 1, q -> ...
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 54 votes
answered by Ajasja https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=745 75 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=64003
I have a list:
data = {4, 5, 7, 8, 9, 5, 3, 2, 1, 2, 13, 12}; I want to take those elements in the list which are located at equal distances, say, every third element, getting the list {7, 5, 1, ...
asked by Suro https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=20003 34 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=20100
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting some errors. Is there something wrong ...
asked by Sriram https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6075 17 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 29 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223991
I’m trying to export a large sparse matrix of dimension 1164960 by 1164960 with 17815680 elements as an .mtx file so I can import it into Python. I first the run the following code successfully.
asked by Daniel Berkowitz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27536 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223879
I have run into a Mathematica object I’ve never seen before and Googling those reveals nothing. I’m talking about VariableReplacementDump and TranscendentalDump. Here’s how I got these:
asked by Lokdal https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=23117 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=224072
Among other series I’ve been working on, I was asked to find whether \[\sum _n 1-\cos (\frac {\pi }{n})\] converged, and Mathematica’s output to
SumConvergence[1 - Cos[Pi/n], n] simply was repeating the ...
asked by Hal https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73083 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223087
Given a list of numbers in decimal form, what is the most efficient way to determine if there are any consecutive 1s in the binary forms of those numbers? My solution so far:
dim = 3; declist = ...
asked by KHAAAAAAAAN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=65587 10 votes
answered by MassDefect https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42264 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223159
While updating my answer for (189038) I noted that some PlotThemes do not work with Mesh in a meaningful way:
SeedRandom["08.01.2019"]; $plotThemes = Map[ToString] @ { Web, Monochrome, Detailed, ...
asked by gwr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=764 9 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223023
Despite having looked over various posts concerning optimizing nested For loop expressions into a functional programming equivalent I still can not figure out how to actually to do this. Such ...
asked by Stuart Poss https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35282 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222895
I create a symbolic matrix using the following:
mat = ToExpression[Table[StringJoin[{"s", ToString[i], ToString[j]}], {i, 1, d}, {j, 1, d}]]
for arbitrary \(d\). Notice that for \(d=2\), this gives
asked by Sid https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26461 8 votes
answered by Edmund https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19542 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222950
I’m looking for a way to re-express a partition given in full form, like \(\{{2, 2, 1, 1}\}\), into the shortened form \(\{2^2, 1^2\}\), i.e. given a partition with repeated entries, count the number of ...
asked by ZeroTheHero https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52937 7 votes
answered by kirma https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3056 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222964
Investigating Function[] , I found:
What is the difference between using a variable (in the case, \(u\)) and a "slot variable"? It seems anything can be done with both. Is there something that ...
asked by Billy Rubina https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=603 7 votes
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222924
I’m trying to efficiently populate elements of a very large (2^20 x 2^20)
symmetric matrix
with 1s - luckily the matrix is very sparse, <0.1the matrix has a very well defined
...
asked by KHAAAAAAAAN https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=65587 7 votes
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=32378
I’m visualizing some hydrogen like atomic orbitals. For looking at plane slices of the probability density, the DensityPlot function works well, and with something like:
Manipulate[ DensityPlot[ ...
asked by Peeter Joot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10 44 votes
answered by xslittlegrass https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1364 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=42359
Following is the equation:
Need to solve for integer values of x,y when a,b lies between -1000 and 1000. Problem is to find the number of integer values of pair (x,y) that satisfy it.
asked by Sahil Sareen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12396 2 votes
answered by bill s https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1783 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8841
I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...
asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 29 votes
answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase spectrum, as well as reconstruct the ...
asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 14 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66538
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
asked by Simpleton Jack https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22399 287 votes
answered by mikuszefski https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7608 440 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 177 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 60 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21544
Is there a way to find a limit of a multivariable function, like
\[\lim _{(x,y)\to (0,0)} f(x,y)\] with Mathematica?
When \(f\) is continuous, we can use
\[\lim _{(x,y)\to (0,0)}\] ...
asked by Dominic Michaelis https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5899 30 votes
answered by whuber https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91 41 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223212
There is a figure given that shows the relation between Forward current(y axis) and forward Voltage (x axis ) for a forward biased diode, with the given formula
asked by Haneen Hussam https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=73068 1 vote
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223025
The GetProcessMemoryInfo from psapi.dll is a helpful function that can be used to monitor the memory wolframkernel.exe used, where how much memory can be used and is actually used by wolframkernel is ...
asked by Frank https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8207 1 vote
answered by Frank https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8207 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=223155
I want to solve the following problem in Mathematica:
I used the following Mathematica code. I am unsure whether this is the correct way of entering the assumptions for the initial and boundary ...
asked by Leponzo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=60411 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222380
In version 10.1 I found a strange Plot behavior I did not anticipate. It seems that various heads including PlusMinus are treated as wrappers and stripped by Plot in a way that is not safe. This ...
asked by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 12 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222464
UPDATE
As suggested by Roman, I’ve included here all my code.
I’m using just bult-in function and compile to boost my code, but I think that it can be better. My code looks like
nof = 30; ...
asked by Magela https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68365 11 votes
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222716
I am having trouble maximizing a function which appears as a curvature of a planar curve.
{tmin, tmax} = {0, 2 Pi} f = -((6-3 Cos[t] - Cos[3 t])/((-11+6 Cos[t] + 8 Cos[2 t] - 6 Cos[3 t] + Cos[4 t]) ...
asked by A. Kato https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62063 8 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222517
I have the following data from which I get an interpolation:
SPE = Interpolation[{{0, 4.08}, {0.5, 9}, {1.5, 12}, {5, 0.158}, {10, 0.158}, {15, 0.415}, {20, 0.802}, {30, 2.64}, {40, 4.99}, {60, ...
asked by mattiav27 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8822 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222407
Question is very simple. If we have
tst = {2,3,4,6,7,9,11} result must be {{2,3,4}, {6,7}, {9}, {11}} There are similar questions, but not exact. My best solution is: myFun[arr_] := ...
asked by lesobrod https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5950 8 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222548
If I have two list such as:
list1 = {{40., 7.50551*10^-10}, {40.,7.50557*10^-10}, {40.,7.50566*10^-10}, {40.0001, 7.50578*10^-10}, {40.0001, 7.50591*10^-10},{40.0001, 7.50607*10^-10}, ...
asked by John https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72900 7 votes
answered by David Keith https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=44700 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222837
How could I get the volume of water on a region as it is filled up with water from below? Assume gravity points in some appropriate downward axis like y (or z in 3D) so the water fills upward from ...
asked by flinty https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72682 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18082
testData = Table[N@Sin[500 x], {x, 0, 100}]; ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full] Gives me Which I do not expect because the Fourier Transform is FourierTransform[Sin[500 ...
asked by C. E. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=731 14 votes
answered by KennyColnago https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3246 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2456
Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data :
asked by 500 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=172 18 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573
I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...
asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes
answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3433
I am using this code to plot a graph, and I am trying to make the font of the legend bigger.
<<PlotLegends` ListLogLogPlot[{Sort[moby]}, PlotRange -> Full, Joined -> True, ...
asked by Julia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=525 20 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=850
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
asked by niklasfi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82 95 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 92 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=34073
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
asked by user64494 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7152 40 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 63 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506
I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta\[\] function. When using this inside of a function or just the function ...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222577
Out of curiosity, I’m trying to implement a natural deduction prover in Mathematica using FindEquationalProof. So far, I’ve implemented a few of the easier rules:
axioms = { ForAll[{A, B}, ...
asked by imas145 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61387 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222571
I am trying to run this code to get the output from NDSolve for 4 dynamical equations. However, I have two issues:
(1) It is taking a very long time (can reach several hours for a given instance) ...
asked by user135626 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19550 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222504
I managed to create a definition for the "Print" style, following the instructions here. However, the result does not work in my v.12.1. On the plus side, a "Print" entry exists at the bottom of the ...
asked by Nicholas G https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=43662 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222002
I would like to clear all definitions of the form f[1,...] in such a way that f[2,...] remain unaffected.
The two methods I know to clear variables don’t seem to apply to this situation:
Pattern
asked by WillG https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59634 10 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 15 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222252
I have acquired many sets of data, which all represent a single function, but which are randomly rescaled by a constant (due to the measurement specifics). I’m looking to effectively stitch them ...
asked by ChaSta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=48457 9 votes
answered by aooiiii https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68990 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221934
Two different examples of same problem:
In: Cases[{f^2, g^3, k^p, h}, x_^n_ -> n] Out: {2,3,p} # The result misses the exponen of h, '1'
The same problem in a different context:
asked by MaxB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66077 8 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221984
Suppose I have a set of points pts, from which I generate a Voronoi diagram VD:
pts = RandomReal[{-1, 1}, {100, 2}]; VD = Show[VoronoiMesh[pts], Graphics[{Red, Point[pts]}]] Now, as per the ...
asked by TumbiSapichu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=53229 7 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222037
Using an answer to this question (Working with Dirac Gamma Matrices using FeynCalc - A simple problem), I defined
Clear[] SetAttributes[, Listable] [_] := If[ == 0, KroneckerProduct @@ ...
asked by FB20 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72314 6 votes
answered by Chanto https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35091 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222285
I have an expression of the form
expr = 3*(a.b)*(c.d)*f[x] + 5*(m.n)*(p.q)*(r.s)*f[y] and want to extract all possible subexpressions matching the pattern ((_).(_))*f[_]. Expected result (in ...
asked by Shadowray https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47416 6 votes
answered by Marius Ladegård Meyer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22099 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222105
I want to use geometric shapes in Mathematica to build complex shapes and use my raytracing algorithm on it. I have a working example where we can get the intersections from a combination of a Cone[] ...
asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 6 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819
In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 197 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 255 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=573
I would like to list all possible times in a 12-hour period, where the hour hand overlaps the minute hand completely. This is really a question about three distinct things - to be done in Mathematica ...
asked by Steve D https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=191 15 votes
answered by Verbeia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336
I am wondering how to implement the multi-peak detecting and fitting in Mathematica.
Following is an example of fitting the data using three peaks (such that the
data ~ peak1 + peak2 + peak3
).
asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 54 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 54 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586
I am trying to use the Export command to convert a list of plots into a *.gif
file, and the
command runs and executes well, but I can’t find the file! Where is it supposed to go? Did it
even work?
asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 49 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3242
For instance, is there some way I can say "let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices,
Simplify[Transpose[Transpose[A].Transpose[B]]]
" and Mathematica would simplify it
to B.A?
asked by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=6669
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
asked by stevenvh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1450 52 votes
answered by Artes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=184 33 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=2930
I have a For loop (with i as a counter), which calculates different values (y1, y2, y3,...) as a function of the variable x. How can I create a table/matrix which contains i lines, each line ...
asked by Solarboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=727 10 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221938
I have to manipulate huge expressions that are rational functions of many (30)
variables
with integer coefficients. Storing them just as a ratio of two polynomials would be
impractical. But they can ...
asked by Vladimir Reshetnikov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7288 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=222179
apparently my computer has problems when I try to perform a calculation with TensorContract.
In particular, with the second answer to my previous question Contracting indices in lists, I want to ...
asked by FB20 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72314 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221941
I’m working through MMA Cookbook by Mangano, page 54. He shows Map is a compact form of Fold function. Is using Fold function important?
myMap3[f_, l_] := Fold[Prepend[#1, f[#2]]&, {}, l]
asked by code9910743 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=59860 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221436
Sometimes, after writing code like
f[] := Module[{a}, ...] and running f[] multiple times, there will be many Temporary symbols of the form a$123 in the Global namespace. Sometimes this happens ...
asked by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 25 votes
answered by Leonid Shifrin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=81 22 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221555
Is there a way to loop through all the Functions (Elementary and Special functions) that exist in Mathematica?
I want to construct a table of some identities and maybe I can discover something ...
asked by Micha Kuczynski https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72609 12 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221609
As it is known in biological system with memory it would be suitable to use fractional derivatives to describe evolution of the system. In a current version of Mathematica 12.1 there is no special ...
asked by Alex Trounev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58388 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221373
Revisiting the problem Limit of partial sums involving inverse squares I found another
difficulty with Sum[]
Consider this sum
s[x_, n_] := Sum[ 1/(i + (n - i) x)^2, {i, 1, n}] Here we assume x ...
asked by Dr. Wolfgang Hintze https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16361 10 votes
answered by Soner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49198 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221540
NB: I am aware of the DeleteStopwords symbol.
I want to remove from a list of words the ones that are likely to be more banal. So for instance if we have
{"exegesis", "mystification", "bread", ...
asked by Diffycue https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46327 9 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221381
With Wolfram Language:
In[7]:= ExportString["foobar", "Base64"] Out[7]= "Zm9vYmFyXDo0ZTJkXDo2NTg3" With the closest command-line software I could think of echo -n 'foobar' | openssl base64 ...
asked by qazwsx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=357 9 votes
answered by Jason B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9490 17 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221767
I personally do not have an AMD CPU but since they are literally becoming quite hot these days, I thought whether the following fix (as proposed here: ...
asked by Ali Hashmi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27331 7 votes
answered by ilian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=145 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=15023
The basic multivariable Taylor expansion formula around a point is as follows:
$$ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac{1}{2!}(\mathbf a \cdot ...
asked by matheorem https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4742 55 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 61 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8895
I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes, I run into the following error:
asked by Zoe Rowa https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1713 36 votes
answered by Yi-Zen Chu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4869 17 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39003
I need to apply Van Gogh’s stroke brush effect to a random image
Take the following image as an example:
Thank you so much if you could help!
asked by user10495 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10495 33 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=26336
I am wondering how to implement the multi-peak detecting and fitting in Mathematica.
Following is an example of fitting the data using three peaks (such that the
data ~ peak1 + peak2 + peak3
).
The ...
asked by Everett You https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1389 54 votes
answered by Silvia https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=17 54 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 460 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 277 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=42359
Following is the equation:
Need to solve for integer values of x,y when a,b lies between -1000 and 1000. Problem is to find the number of integer values of pair (x,y) that satisfy it.
asked by Sahil Sareen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12396 2 votes
answered by bill s https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1783 4 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736
I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems
I would ...
asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 124 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221405
I want to plot a binary tree in Mathematica where the nodes are labeled according to a given rule. In fact, whether a node has a left child or a right child or both, will be determined by a rule. And ...
asked by Mwen Rele https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72568 1 vote
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221414
In order to let other users with Mathematica 12.x test this problem for me, I now use FileTemplate instead of Splice.
I want to splice (with FileTemplate) the following file that has been simplified ...
asked by Money Oriented Programmer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42141 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221489
I am trying to model a simple 2D steady state heat conduction problem using automatically generated Q2 elements.
The problem consists of a square domain with prescribed temperatures along the bottom ...
asked by DvanHuyssteen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69831 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221160
Why does Count not work with SparseArrays, and is there any function I can use to replace it?
What would be an efficient workaround?
Example:
a=ConstantArray[0,{10},SparseArray]; Count[a,0] (* ...
asked by Daniel https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19534 9 votes
answered by thorimur https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=63584 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=220972
Suppose I have a function with a signature like g[expr, _?(f), {1}, Heads -> False] and I want to access it as an operator by giving the first argument last. I see there are various ways of doing ...
asked by user13892 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13892 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221155
I have a number of large data sets in Excel and .dat from OMEdit Modelica that then need to import some or all of it to Mathematica for manipulation and plotting. Importing the data is easy enough ...
asked by Chris B https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=58764 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221079
Stumbled on Local variables when defining function in Mathematica in math.SE and decided to ask it here. Apologies if it is a duplicate - the only really relevant question with a detailed answer I ...
asked by https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=35000 8 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221082
I use Mathematica version 12.1 on Windows 10.
I have four equations in four unknowns.
Is there a trick to make Mathematica solve these?
I tried Solve and NSolve and it is not able to do it. ...
asked by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 8 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=220842
Overview: I have written a few mathematica packages, always using the method of writing my code in a mathematica notebook and letting mathematica autogenerate the .m package file. Currently I do not ...
asked by Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5033 8 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221255
I am doing a StreamPlot and something seems wrong with the output.
StreamPlot[{0, -(y - x)^3}, {x, -3, 3}, {y, -3, 3}] The plot is attached and I highlighted the issue in red Shouldn't the ...
asked by Moo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36141 7 votes
answered by user2432923 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61643 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=135937
Salacious title, but true story.
dmethyl1 = { {0, 0}, {.25, 1}, {.5, 7}, {1, 26}, {1.5, 40}, {2, 45}, {2.5, 45}, {3, 44}, {3.5, 44}, {4, ...
asked by Prisoners Dilema https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46025 42 votes
answered by bobthechemist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7167 23 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=29203
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase spectrum, as well as reconstruct the ...
asked by user8727 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8727 14 votes
answered by Nasser https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70 32 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=11819
In today’s news, scientists found a bright object on one of Curiosity’s photos (it’s near the bottom of the picture below). It’s a bit tricky to find - I actually spent quite some time staring at the ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 197 votes
answered by Niki Estner https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=242 255 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16485
I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about "Power programming with Mathematica" ...
asked by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 158 votes
answered by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 232 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=37266
Today, I found the Euler Project. Problem #2 is
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
1, ...
asked by xyz https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9627 34 votes
answered by rcollyer https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52 46 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19035
I asked Mathematica to compute the following
Solve[c (1-x)^2-x^(1/4) == 0, x] and it returned this: x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 + 70 #1^4 c^4 - 56 #1^3 c^4 + 28 ...
asked by ronanymous https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5730 37 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 63 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=59132
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
asked by Putterboy https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=16069 50 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 65 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221222
I would like to generate a plot with the y axis on the graph. In a "normal" numeric plot I do this using the AxesOrigin option. How to I specify the crossing point in a DateListPlot?
Here’s the MWE ...
asked by jmm https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57731 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=221284
I am trying to create a simple audio player but I am stuck at designing the seek bar. I am using the AudioStream framework.
After loading music in a variable stream, I can access its position using ...
asked by Sâu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=67944 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=220846
I have a parametric function defined by the x and y functions:
x = r*Cos[w_0*t - w_L*t] + z*Cos[w_P*t - w_L*t] y = r*Sin[w_0*t - w_L*t] + z*Sin[w_P*t - w_L*t]
I can change the variables ...
asked by Cameron_3298 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72418 1 vote
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219700
Bug introduced in 12.1.0
Could anybody help?
NotebookDirectory[] function began working wrong in 12.1 (the bug was not present in 12.0 and earlier versions).
When folder name includes Russian ...
asked by Alexander https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72011 13 votes
answered by ilian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=145 10 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=220003
Consider the following example:
Suppose I am interested in words that contain all the letter of the list characters={"e","t","l","a","b"} at least once. An example would be the word "abilities" or a ...
asked by user13892 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13892 12 votes
answered by Jason B. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9490 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219687
Is there a way to do this natively in Mathematica? I read in several places that this is possible with LibraryLink, but I don’t have a lot of experience with C and so I’m having trouble implementing ...
asked by beets https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=72007 8 votes
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219990
First some comments. This same calculation works beautifully in 2D with essentially the same code. I have copied it largely unaltered into 3D as part of a migration to 3D so that I can do more complex ...
asked by Paul Harrison https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=69377 7 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219963
I don’t understand the difference between these products:
Wolfram Script
Wolfram Engine
Would someone help me understand what these are? And how it differs from just using Mathematica in the ...
asked by QuantumDot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2048 6 votes
answered by morbo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=48686 0 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219758
I’ve found that the latest MATLAB icare() solver includes the possibility to find also the anti-stabilizing solution of the Riccati equation. I haven’t found a similar option on Mathematica. Is there ...
asked by Mirko Aveta https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36621 6 votes
answered by Suba Thomas https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5998 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=220154
A simple example
Clear["Global`*"]; data = TimeSeries[{1, 2, 1, 3, 0, 0, 0, 2, 21, 15, 21, 7, 11, 5, 10, 18, 73, 38, 103, 21, 35, 31, 46, 31, 35, 94, 71, 48, 78, 71, 74, 95, 95, 56, ...
asked by Vaggelis_Z https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5052 5 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=13277
At the moment I am trying to construct a bifurcation diagram of the iterative function \(f(x)=\) \(ax-1.1975x^3\). I’ve scoured the internet for pre-made bifurcation diagrams and found many (mostly of the ...
asked by Mel https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=3249 26 votes
answered by Mark McClure https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66969
Here is a start. I’m looking for a nice way to draw it.
Graphics[{EdgeForm[Black], White, Polygon @ {{0, 0}, {-1, 0}, Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, Polygon @ {{0, ...
asked by matrix89 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=5379 24 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 21 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66538
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
asked by Simpleton Jack https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22399 287 votes
answered by mikuszefski https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7608 440 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18419
Mathematica 9.0 looks a bit fuzzy on the retina screen, how can I increase the resolution?
Here another screenshot showing a direct comparison between the browser and Mathematica
asked by Tom Wellington https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2437 43 votes
answered by canadian_historian https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19 20 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8586
I am trying to use the Export command to convert a list of plots into a *.gif file, and the command runs and executes well, but I can’t find the file! Where is it supposed to go? Did it even work?
asked by Patrick Da Silva https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1785 37 votes
answered by Vitaliy Kaurov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13 49 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=39003
I need to apply Van Gogh’s stroke brush effect to a random image
Take the following image as an example:
Thank you so much if you could help!
asked by user10495 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=10495 33 votes
answered by Simon Woods https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=862 51 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3069 Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
asked by sjdh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=515 177 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 60 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219919
I have been fighting unsucessfully with the intricacies of creating Mathematica packages (Private, scopes , context) for a long time. I just need a simple version of Matlab scripts, to be able to ...
asked by florin https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=54979 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219883
Is there any newer book or online resource that would be good introductory text to probability with Mathematica? I have Introduction to Probability with Mathematica by Hastings but it is over 10 years ...
asked by grga https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70392 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219973
I have defined a function ConvertToMarkdown that does some long processing of a notebook: converts it to markdown, save inputs/outputs as images, generates a word cloud etc., that can take multiple ...
asked by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219629
I’m trying to get some rays to bounce in a circle. But I want to be able to control the reflections, i.e. the direction the rays bounce in the circle. I have a MWE below, and it is severely limited by ...
asked by Tomi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=36939 10 votes
answered by MassDefect https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42264 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219317
Now I can use this functionResourceFunction["DarkMode"][] to use the dark mode, but when I turn on Mathematica again, the black mode will not work. How can I set to use the black mode permanently.
asked by https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71882 9 votes
answered by M.R. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=403 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219412
I have a listed of Tupels
list = {{10, 5}, {20, 4}, {20, 3}, {10, 6}}; If there are two elements a and b for which a[[1]] <= b[[1]] && a[[2]] <= b[[2]] then I would like to delete ...
asked by fravity https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22275 8 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 7 votes
subsubsectionMathematica is unable to compute the derivative of the function \(\frac {\sin ^2(x)}x\) https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219273
Consider the function \[f: \mathbb R\to \mathbb R, x\mapsto \begin {cases}\frac {\sin ^2(x)}x, & x\neq 0, \\ 0, & x=0.\end {cases}\]
It is clear that \(f\in \mathcal C^1(\mathbb R)\) and that
asked by Maximilian Janisch https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=68670 8 votes
answered by Bob Hanlon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=9362 12 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219282
I am using Mathematica and I would like to download the dataset "Epidemic Data for Novel Coronavirus COVID-19" for basic investigation from Wolfram homepage. Can anyone give me some instructions or ...
asked by Johann Riedler https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71867 7 votes
answered by morbo https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=48686 6 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219198
I am trying to understand the numerical integration routine by using as a benchmark the function
f[x_] := -x^2 + x^4 used to define the following function g[z_] := NIntegrate[1/Sqrt[-f[x]], {x, z, ...
asked by Smerdjakov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=55615 7 votes
answered by MassDefect https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42264 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219593
Backslide introduced in 10.0, persisting through 12.1.
I am trying to solve the following differential equation and plot the result:
ClearAll["Global`*"] rin = 10^-30; sol = NDSolve[{Sqrt[x] ...
asked by mattiav27 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=8822 6 votes
answered by xzczd https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1871 2 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18393
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
asked by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 459 votes
answered by Michael E2 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4999 277 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=180
Say I have a list x={2,4,6,8,10} and I want to find out the positions of the elements that are greater than 7. Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
asked by PeterR https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=140 62 votes
answered by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 60 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=66538
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
asked by Simpleton Jack https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22399 287 votes
answered by mikuszefski https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7608 440 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=78451
I want to plot the following function:
\[\int \left (\frac {\Gamma (x+1)}{2}-\frac {\Gamma (x-1)}{2}\right ) \, dx\]
asked by Anixx https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=651 3 votes
answered by k_v https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=24727 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=21884
I have two lists of values
xx = {0.1, 0.3, 0.35, 0.57, 0.88, 1.0} yy = {1.2, 3.5, 4.5, 7.8, 9.0, 12.2}
I want to make a scatter plot (list plot) with xx as x axis and yy as y axis. The help ...
asked by Patrick Li https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2403 27 votes
answered by Eric Thewalt https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6313 38 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=16485
I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about "Power programming with Mathematica" ...
asked by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 158 votes
answered by Todd Allen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=249 232 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3306
I have a complex expression with real positive variables only.
Mathematica Input Style:
PP = -(( ( Cosh[y1 ] + Sinh[y1 ])(- Cosh[(-L + y2) ] + Sinh[(-L + y2) ])) /(s (2 Cosh[L ] ...
asked by max https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=796 31 votes
answered by nixeagle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=814 50 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219430
Running the following code takes about 30 min on my laptop (everything before the Reduce is instant) and produces a Large output that Mathematica does not display, only shows buttons Show more, Show ...
asked by Sander Heinsalu https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=6211 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219195
I am getting this error HElP....
asked by Ajit Yadav https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71840 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219616
I am trying to implement a module to determine the best value for the smoothing parameter of a smoothing spline interpolation of a given dataset. To calculate the cross-validation score of a given ...
asked by Daniele Binosi https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=25023 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218764
tl;tr; How to improve performance of regularised Interpolation?
Context
Since Version 12, Mathematica now incorporates a range of (underrated IMHO) regularisation methods to Fit and FindFit.
asked by chris https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1089 17 votes
answered by chris https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1089 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218983
This is a follow-up on How to handle discontinuity in diffusion coefficient?
Consider diffusion of \(u(t,x)\) on the domain \(x \in [0,2]\) with some simple boundary conditions such as \(u(0) = 2, u(2) =\)
asked by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 13 votes
answered by Tim Laska https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=61809 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218859
TreePlot[{ {0 -> "Mr 1", 1/10}, {0 -> "Mr 2", 2/10}, {0 -> "Mr 3", 3/10}, {0 -> "Mr 4", 4/10}, {"Mr 1" -> "A1", 2/10 }, {"Mr 1" -> "B1", 1/10 }, {"Mr 1" ...
asked by CasperYC https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=62701 13 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219033
It seems since v12.1 a new doc type, tech note, is included in the documentation.
However, I cannot find an index page for the tech notes. So how can I list all such tech note pages?
asked by sunt05 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=260 10 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219115
Given list \(L\) consisting only of \(0\)’s and \(1\)’s, we read \(L\) backwards and construct a new list \(O\) such that: (we start with \(O=\{1\}\) and then apply the two rules:)
if we encounter \(n\) ...
asked by Vepir https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=49840 9 votes
answered by Victor K. https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1351 5 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219020
Mathematica 12.1 introduced a number of amazing shaders such as StippleShading.
Is there a way to control the grain size of StippleShading?
On a standard resolution screen it looks like this:
asked by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218833
Wolfram makes the COVID-19 case data available in a form that is conveniently formatted for processing in Mathematica.
It can be accessed using:
data2 = ResourceData[ResourceUpdate["Epidemic Data ...
asked by theorist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45215 9 votes
answered by LouisB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=22158 7 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=5790
If we have two vectors, \(a\) and \(b\), how can I make Jacobian matrix automatically in Mathematica?
$$ a=\left( \begin{array}{c} x_1^3+2x_2^2 \\ 3x_1^4+7x_2 \end{array} \right);b=\left(
asked by George Mills https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1012 37 votes
answered by Jens https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=245 49 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736
I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems
I would ...
asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 124 votes answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=18
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
asked by J. M.’s technical difficulties https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=50 536 votes
answered by faysou https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66 473 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=8841
I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...
asked by Matt Groff https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=1735 29 votes
answered by Peter Breitfeld https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=307 24 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=194384
In version 2.0 of Mathematica there was a command, ReadProgrammerIntentions[ ] which allowed it rapidly compose code that could solve problems simple to complex, based on my requirements. Understand ...
asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 52 votes
answered by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 38 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=46538
I want to get the following expression from Mathematica to LaTeX:
\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \]
I have tried to use inbuilt ’symbol’ character from the special ...
asked by Steve Hatcher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=13314 18 votes
answered by Sjoerd C. de Vries https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=57 25 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=208045
I’m just curious. My friend just told me that Mathematica is mostly for symbolic calculation and not efficient for Numerical computations. He told me that’s the reason most of the people don’t use ...
asked by Gummala Navneeth https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=66938 44 votes
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 73 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219057
I need to use the following code to do some calculations. But the running speed of this code is too slow. How can I modify this code to improve the running speed?
Cb = 0.5; Ch = 5./7; = ...
asked by Please Correct GrammarMistakes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=219035
I tried to compute the following limit:
Limit[Series[ 1/(1/x^2) (Sin[y x]/(x^4))^2 - Sin[y x]/y(x^3) + 1/x^2, {x, 0, 5}], x -> 0, Assumptions -> {y > 0}] the output :
asked by Johe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71663 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218701
i need help to convert this code written in matlab about Butterworth filter:
%remove high-frequency components by 0.5-h butterworth filter; n =2; Wn =[1/30/0.5]; %30-min low-pass filter (LPF)%
asked by Iman Khaki https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71671 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218535
How can I determine if two mutable data structures (DataStructure) are truly the same? I do not mean checking if they have the same value. I mean checking if they are the same data structure, i.e. ...
asked by Szabolcs ( https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 ) 15 votes
answered by ilian ( https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=145 ) 14 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=217230
Mathematica has very high quality and extensive documentation and good getting help system (? Solve as an example; there maybe are more too). Is there all including official documentation about ...
asked by vasili111 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=11639 14 votes
answered by WReach https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=142 11 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=217226
I’m trying to make a ContourPlot3D that needs to be transparent. With transparency, however, something odd happens.
With PerformanceGoal->"Speed"
, the colors look fine.
With ...
asked by Peter Todd Williams https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70508 11 votes
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218539
When I divide this number by zero I get this for an answer. ans = 2345900/0 What is surprising is that in taking the square root, Mathematica seems to map the entire universe to some town ...
asked by MikeY https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=47314 9 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=217227
I want to draw a parametric equation with ś like the figure below: But I don't get the result I want when I run the following code. What can I do to get it? ParametricPlot[{x, śx^2}, {x, 0, 1}, ...
asked by Please Correct GrammarMistakes https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=42417 9 votes
answered by Mr.Wizard https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=121 16 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=217205
In[71]:= 0.6*0.8048780487804877` Out[71]= 0.482927 In[72]:= 0.3*0.8414634146341463` Out[72]= 0.252439 In[74]:= (0.6*0.8048780487804877`) + 0.3*0.8414634146341463` Out[74]= 0.735366
asked by htam_ujn https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70502 9 votes
answered by m0nhawk https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2342 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=217169
I have a 2D rectangular domain with -L/2 < x < L/2 and 0 < y < D0, which is divided into two parts, with a sinusoidal curve y == 1 + Cos[2 Pi x/L] separating the two. I want to solve ...
asked by Physicist https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=41581 8 votes
answered by user21 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18437 8 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=736
I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems
I would ...
asked by Thomas Rot https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=227 124 votes
answered by Simon https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34 45 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=188139
Some (older) members of this group might remember playing vinyl LP records. Recently, at the Abbey Road studio there was a spiroglyphics coloring book for sale. It looks like a nice programming ...
asked by TheDoctor https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=2263 13 votes
answered by b3m2a1 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38205 18 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=24169
I’m new to Mathematica and I need to ask how to graph a sphere, cylinder, etc.. using cartesian equations.
For example in sphere’s case \(x^2+y^2+z^2=1\)
I tried to use Plot3D but it doesn’t ...
asked by German https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=7145 7 votes
answered by Dr. belisarius https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=193 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=19669
Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
asked by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 163 votes
answered by faleichik https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=219 232 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=136974
My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.
asked by zeros https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=26849 69 votes
answered by Anton Antonov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34008 93 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=3506
I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a function or just the function ...
asked by night owl https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=116 17 votes
answered by Heike https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=46 19 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=57763
When I solve the aforementioned equation for \(W\) or \(A\) on Mathematica I get a long and ugly equation in return, namely one of the solutions for \(W\) is: (attempt to read at your own health)
asked by J.D’Almbert ( https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19257 ) 8 votes
answered by Alexei Boulbitch ( https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=788 ) 13 votes
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=217164
Code as following:
In[1]:= constants = Quantity /@ {"PlanckConstant", "BoltzmannConstant", "MolarGasConstant"}; Print[UnitSimplify[ UnitConvert[Quantity["AvogadroNumber"]*constants[[2]]]] // N];
asked by ( https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=19360 ) 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218431
I have a list of prices and a list of dates, but I have 154 more prices than dates. So I want to delete random prices to match both lists, however, every time I run the block of code I get a different ...
asked by trashparticle https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=71573 1 vote
https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=218297
I have a work flow that involves initially specifying a matrix function (or a matrix of functions), e.g. f[x_]:={{Exp[x],Sin[x]},{Cos[x],Log[x]}}
This works well for what I am using it for. I can ...
asked by user3353819 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=34650 1 vote
https://mathematica.stackexchange.com/questions/163638/how-can-i-access-nasa-images-and-apis
I ♥ NASA. You ♥ NASA. We all ♥ NASA.
So how can I use the images and things they expose in their APIs in Mathematica?
- asked by b3m2a1 (23 votes), answered by b3m2a1 (29 votes)
https://mathematica.stackexchange.com/questions/163469/access-last-variable-in-a-pure-function
# is the first argument of a pure function, #n the nth, ## are all variables and ##n all beginning with the nth variable.
Now, I would like to access the last argument. In a list, this would be ...
- asked by riddleculous (13 votes), answered by Henrik Schumacher (14 votes)
https://mathematica.stackexchange.com/questions/163498/ordered-randomsample
This feels like a basic question yet I failed to find an answer.
(*arbitrary list of unique elements, does not need to be sorted*) list = CharacterRange["a", "h"]; n = 5; RandomSample[ list, n]
asked by Kuba (11 votes), answered by Coolwater (13 votes)
Bug introduced in 8 or earlier and persisting through 11.2.0
>From Refresh docs: Refresh[expr,None] specifies that the value of expr should never automatically be refreshed. ClearAll[z] ...
asked by Kuba (8 votes)
I have some code that process very large flat files in to separate HSQL(Standalone) databases using ParallelSubmit and JDBC for each file using the strategy in this post (19542). Lately I keep ...
asked by Edmund (8 votes), answered by Edmund (5 votes)
https://mathematica.stackexchange.com/questions/163566/three-differential-equations
I have the next figure with inflow and outflow rates:
And I need to calculate the time for which the pollution will be 50% from the initial value. Assuming that all lakes have the same pollution ...
asked by Darius Ionut (8 votes), answered by Henrik Schumacher (8 votes)
I copied the title and concept for this question from here. I have
data = {{"ID", "Value"}, {1, 48}, {1, 45}, {1, 52}, {1, 43}, {1, 41}, {2, 50}, {2, 42}, {2, 51}, {2, 52}, {bb, 52}, {bb, 54}, ...
asked by ramesh (7 votes), answered by kglr (8 votes)
https://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
asked by Tianxiang Xiong (53 votes), answered by Artes (41 votes)
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
asked by J. M. (483 votes), answered by faysou (430 votes)
https://mathematica.stackexchange.com/questions/163756/why-boundingregion-does-not-work-well
Bug introduced in 10.0 and persisting through 11.2.0
I have a set of data points describing an ellipse in the plane. I want to obtain the best ellipse that fits them.
As a first attempt, I use ...
asked by José Antonio Díaz Navas (5 votes)
I was having a look at the DLMF chapter on integrals with coalescing saddles, and there are a few things that I’d like to try out with the functions it describes, including e.g. the Pearcey integral,
asked by Emilio Pisanty (2 votes)
https://mathematica.stackexchange.com/questions/163391/can-findfit-be-used-with-units
I am trying to use the units capabilities of Mathematica throughout a course that I am teaching, but am finding that it isn’t uniformly implemented across many functions. In particular, I would love ...
asked by Kevin Ausman (1 vote)
================================== Top new questions this week: ==================================
[Why is Unevaluated[#]& different from Unevaluated?] https://mathematica.stackexchange.com/questions/163291/why-is-unevaluated-different-from-unevaluated
{a, b, c} = {1, 2, 3}; Unevaluated /@ Unevaluated@{a, b, c} (* {Unevaluated[a], Unevaluated[b], Unevaluated[c]} *) Unevaluated[#]& /@ Unevaluated@{a, b, c} (* {Unevaluated[1], Unevaluated[2], ...
- asked by Roman (18 votes), answered by Szabolcs (19 votes)
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[Building a GitBook with Mathematica] https://mathematica.stackexchange.com/questions/163193/building-a-gitbook-with-mathematica
GitBook is a fun little website that will take Markdown source material and build a little book out of it.
How can I use Mathematica to build a GitBook with a minimum of effort?
- asked by b3m2a1 (14 votes), answered by b3m2a1 (18 votes)
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[How to create a vertical bullet gauge?] https://mathematica.stackexchange.com/questions/163201/how-to-create-a-vertical-bullet-gauge
Originally posted in MathematicaMeta SE, titled "I can’t understand why Mathematica has an excellent (perhaps the best!) BulletGauge command (with multiple options)", as a reflexion about the ...
- asked by Mika Ike (10 votes), answered by kglr (14 votes)
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[Specialized form of Outer[f, list, list] for symmetric f] https://mathematica.stackexchange.com/questions/163240/specialized-form-of-outerf-list-list-for-symmetric-f
Consider a function f that is symmetric with regard to its two arguments i.e. f[x,y] == f[y,x]. Using Outer one can for instance build a correspondence matrix that computes some distance measure f ...
- asked by Sascha (9 votes), answered by Henrik Schumacher (5 votes)
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[How to convert a string having nested parentheses into an expression?] https://mathematica.stackexchange.com/questions/163184/how-to-convert-a-string-having-nested-parentheses-into-an-expression
I am a Wolfram Language/Mathematica beginner and trying to convert STEP ISO10303 commands into geometrical regions. A simple command looks like
(vector(a,(b,c)),line(d,(e,f))
I tried with String ...
- asked by Markus Sonderegger (9 votes), answered by John Doty (9 votes)
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[Is there any way to speed up this code that’s Maximizing a function got from numerical integration?] https://mathematica.stackexchange.com/questions/163204/is-there-any-way-to-speed-up-this-code-thats-maximizing-a-function-got-from-num
I have this code below, which is calculating the Binding energy of an electron in a Quantum Well Wire with a hydrogenic impurity in it. Well you don’t have to care much about what kind of calculation ...
- asked by tyler_house (7 votes), answered by Michael E2 (7 votes)
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[Joining all the keys of a list of rules that point to matching values] https://mathematica.stackexchange.com/questions/163068/joining-all-the-keys-of-a-list-of-rules-that-point-to-matching-values
Suppose I have a list of rules whose keys are not of identical structure (in my case, the keys are either lists of at least one symbol or symbols alone):
rules = {{a} -> 1, {b, c} -> 1, d -> ...
- asked by user170231 (7 votes), answered by Kuba (10 votes)
================================== Greatest hits from previous weeks: ==================================
[How to calculate scalar curvature Ricci tensor and Christoffel symbols in Mathematica?] https://mathematica.stackexchange.com/questions/8895/how-to-calculate-scalar-curvature-ricci-tensor-and-christoffel-symbols-in-mathem
I am seeking a convenient and effective way to calculate such geometric quantities. I’ve used packages like TensoriaCalc, but they don’t work at all time. Sometimes, I run into the following error: ...
- asked by Zoe Rowa (29 votes), answered by Yi-Zen Chu (12 votes)
—————————-
[xkcd-style Plots] https://mathematica.stackexchange.com/questions/11350/xkcd-style-plots
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over PlotLegends to have these ...
- asked by Amatya (554 votes), answered by Simon Woods (409 votes)
================================== Can you answer these? ==================================
[Is ClearAttributes built-in functon work in current cell only?] https://mathematica.stackexchange.com/questions/163223/is-clearattributes-built-in-functon-work-in-current-cell-only
I have a question. Is ClearAttributes the built-in functon work in current cell only? This is my code:
In first cell: Set[a, 6] In second cell: ClearAttributes[Set, HoldFirst] Attributes[Set] ...
- asked by SIJA (1 vote)
—————————-
[How to convert Piecewise into KroneckerDelta form by FullSimplify?] https://mathematica.stackexchange.com/questions/163274/how-to-convert-piecewise-into-kroneckerdelta-form-by-fullsimplify
The question comes from the last example of this topic in the Wolfram documentation.
SeriesCoefficient[E^x^2, {x, 0, n}] However, my (v11.1) output is $\begin{cases} \frac1{{\sf ...
- asked by ooo (1 vote)
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[Code behind these Video Playback demos?] https://mathematica.stackexchange.com/questions/163008/code-behind-these-video-playback-demos
There are only two known examples of video playback (from a file) within a (non-cloud) notebook:
Visualizations in Graph Theory with the Wolfram Language (at time 3:32) Mathematica and CUDA, ...
- asked by user5601 (3 votes)
================================== Top new questions this week: ==================================
[What’s the default colormap (or color scheme) used in mathematica?] https://mathematica.stackexchange.com/questions/162883/whats-the-default-colormap-or-color-scheme-used-in-mathematica
For example, the colors used on this page: http://reference.wolfram.com/language/ref/ContourStyle.html
or here: https://www.wolfram.com/mathematica/new-in-10/plot-themes/default.html
or here: ...
- asked by Alex (8 votes), answered by kglr (7 votes)
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[\({\frac {\partial ^{2} u}{\partial {x}^{2}}} +{\frac {\partial ^{2} u}{\partial {y}^{2}}} =0\) with one boundary at infinity] https://mathematica.stackexchange.com/questions/162691/frac-partial2-u-partial-x2-frac-partial-2-u-partial
Is there a trick to make Mathematica solve
\[{\frac {\partial ^{2} u}{\partial {x}^{2}}} +{\frac {\partial ^{2} u}{\partial {y}^{2}}} =0\] with one boundary condition at \(\infty \)?
Boundary ...
- asked by Nasser (8 votes), answered by ZufolgeWeierstrass (13 votes)
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[How to make simple closed curve that can be smoothly morphed using locators] https://mathematica.stackexchange.com/questions/162711/how-to-make-simple-closed-curve-that-can-be-smoothly-morphed-using-locators
Given a simple closed curve in 2D with some locators on it, I would like to have be able to stretch and squish parts of the curve by moving the locators to morph the curve into another simple closed ...
- asked by Michael McCain (8 votes), answered by halirutan (12 votes)
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[Approximation with radial basis functions] https://mathematica.stackexchange.com/questions/162768/approximation-with-radial-basis-functions
I want to approximate some functions with basisfunctions, which can be easy Fourier-transformed. So I got the idea to approximate my function with Gaussian normal-distribution curves. This led me to ...
- asked by pcalc (7 votes), answered by Anton Antonov (7 votes)
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[How to Discretize the Following Region Using Reasonable Bounds?] https://mathematica.stackexchange.com/questions/162674/how-to-discretize-the-following-region-using-reasonable-bounds
I want to accurately discretize the implicit equation \(x^2+x+y^2+\sin (4xy)+\sin (3xy)=3.9\).
To get the whole discretized shape, I’m forced to use oversized bounds x,-70,80 and y,-70,80
curve = ...
- asked by Arbuja (7 votes), answered by Carl Woll (5 votes)
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[Replacement for GraphJoin] https://mathematica.stackexchange.com/questions/162900/replacement-for-graphjoin
According to MathWorld » GraphJoin, Mathematica could compute the join of two graphs with the GraphJoin command, part of Combinatorica. This command no longer works as of v10, and I cannot find a ...
- asked by Bryan Clair (5 votes), answered by kglr (6 votes)
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[How can I make a DensityPlot3D over a triangle?] https://mathematica.stackexchange.com/questions/162852/how-can-i-make-a-densityplot3d-over-a-triangle
I know that I can plot over 3D-regions like balls via
DensityPlot3D[(x^2 + y^2 + z^2)^2, {x, y, z} Ball[{0, 0, 0}, 1]]
But, not surprisingly, this breaks down for 2D-regions like triangles.
How ...
- asked by java4ever (5 votes), answered by rcollyer (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How do I clear all user defined symbols?] https://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
- asked by niklasfi (66 votes), answered by Artes (63 votes)
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[How to calculate contour integrals with Mathematica?] https://mathematica.stackexchange.com/questions/34073/how-to-calculate-contour-integrals-with-mathematica
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
- asked by user64494 (31 votes), answered by Artes (54 votes)
================================== Can you answer these? ==================================
[Apply a classifier to a column in excel and export side by side result?] https://mathematica.stackexchange.com/questions/162901/apply-a-classifier-to-a-column-in-excel-and-export-side-by-side-result
I’m relatively new to using Mathematica, and I was able to create a Classifier from a training set of about 3,000 pairs of non-numerical text strings.
I have my test set of about 20,000 records in an ...
- asked by M0RPH0RX (2 votes)
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[Solving a cumulative distribution from a first order condition] https://mathematica.stackexchange.com/questions/162825/solving-a-cumulative-distribution-from-a-first-order-condition
I could use some guidance in using Mathematica’s NDSolve. I’m attempting to numerically uncover a cumulative distribution function (CDF), \(F(p)\), with density \(f(p)\) from a first order condition, ...
- asked by J.R. (1 vote)
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[Fourier | Examples | Applications | Frequency Identification: high resolution: what trick is this?] https://mathematica.stackexchange.com/questions/162661/fourier-examples-applications-frequency-identification-high-resolution-w
My question is regarding one of the examples in the Documentation Center for the built-in symbol Fourier:
Fourier | Examples | Applications | Frequency Identification
Fourier is used to find the ...
- asked by Jack (1 vote)
================================== Top new questions this week: ==================================
[How fast is my fidget spinner spinning? A sound experiment!] https://mathematica.stackexchange.com/questions/162303/how-fast-is-my-fidget-spinner-spinning-a-sound-experiment
I would like to measure how fast my 6-bladed fidget spinner spins. To do so, after giving it a hard spin, I gently touch the spinner with a wooden stirring stick to create a buzzing sound which ...
- asked by Miladiouss (17 votes), answered by Miladiouss (10 votes)
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[Sub-packages and auto-completion] https://mathematica.stackexchange.com/questions/162386/sub-packages-and-auto-completion
Cross-posted on Wolfram Community
I have a Mathematica application that consists of two sub-packages, corresponding to the contexts foo‘ (foo.m) and foo‘b‘ (b.m). Some of the definitions in foo.m ...
- asked by Szabolcs (11 votes), answered by b3m2a1 (2 votes)
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[Why does Cases not find a match to the pattern using _. when n is a number other than 1?] https://mathematica.stackexchange.com/questions/162559/why-does-cases-not-find-a-match-to-the-pattern-using-n-when-n-is-a-number-oth
I am not good in patterns in Mathematica, and so can’t figure what I am doing wrong.
This example works, when the exponent is 1
ClearAll[y,x,n] Cases[{( y[x]/x)^1}, (y[x]/x )^(n_.) :> n]
But ...
- asked by Nasser (10 votes), answered by m_goldberg (9 votes)
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[How to make an Epilog moveable with drag and drop] https://mathematica.stackexchange.com/questions/162572/how-to-make-an-epilog-moveable-with-drag-and-drop
I would like to make an Epilog moveable. For example, the following code generates a Manipulate with a framed pane containing some notes. I would like the user to be able to move those notes anywhere ...
- asked by Michael McCain (8 votes), answered by Mike Honeychurch (9 votes)
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[Map every second element of a list] https://mathematica.stackexchange.com/questions/162334/map-every-second-element-of-a-list
I’ve loaded a CSV:
Colors = Import[ "d:\\bitbucket\\diversity\\data\\nlcd\\nlcd-colors.csv", "CSV"] {{0., " 0.00000000000 0.00000000000 0.00000000000"}, {11., " 0.27843137255 0.41960784314 ...
- asked by pnz (8 votes), answered by Kuba (13 votes)
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[Table of precedence values for all System‘ symbols] https://mathematica.stackexchange.com/questions/162474/table-of-precedence-values-for-all-system-symbols
Has anyone created a table listing the precedences for all symbols? Also, it would be nice if there were a function that for a given precedence value or interval, returned all the symbols with that ...
- asked by Carl Woll (7 votes), answered by Carl Woll (8 votes)
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[How to make a custom DynamicImage which support mouse wheel and show pixel value?] https://mathematica.stackexchange.com/questions/162311/how-to-make-a-custom-dynamicimage-which-support-mouse-wheel-and-show-pixel-value
The built-in DynamicImage just click the plus sign or minus sign to rescale the image. I have to say click is a not very good operation. Could we make the custom DynamicImage which support the mouse ...
- asked by yode (7 votes), answered by M.R. (3 votes)
================================== Greatest hits from previous weeks: ==================================
[xkcd-style Plots] https://mathematica.stackexchange.com/questions/11350/xkcd-style-plots
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over PlotLegends to have these ...
- asked by Amatya (553 votes), answered by Simon Woods (409 votes)
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[Why round to even integers?] https://mathematica.stackexchange.com/questions/2116/why-round-to-even-integers
According to the Mathematica help:
Round rounds numbers of the form x.5 toward the nearest even integer.
For example: Round[{0.5, 1.5, 2.5, 3.5, 4.5}] gives {0, 2, 2, 4, 4}
What’s the ...
- asked by wxffles (69 votes), answered by Per Alexandersson (43 votes)
================================== Can you answer these? ==================================
[How can I check that a graph is edge weighted, fast?] https://mathematica.stackexchange.com/questions/162391/how-can-i-check-that-a-graph-is-edge-weighted-fast
I need to check if a graph is edge-weighted while maintaining good performance.
This should be an easy task, but it is not. It is a good example of why it is so terribly frustrating to work with ...
- asked by Szabolcs (5 votes)
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[contour of inside of a volume] https://mathematica.stackexchange.com/questions/162306/contour-of-inside-of-a-volume
I have the following volume:
RegionPlot3D[-j^2*y^2 + j*l < 11, {l, 0, 10}, {j, 0, 10}, {y, 0, 1}]
However, I am not able to obtain a 2D graph from it (contour), which shows the region inside the ...
- asked by Darrin Cope (1 vote)
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[Finsler or Lagrange geometry package?] https://mathematica.stackexchange.com/questions/162489/finsler-or-lagrange-geometry-package
I was wondering if there exist any packages or examples of work on Finsler-Lagrange geometry. I need it to do symbolic calculations, as for example calculations of non-linear connection coefficients, ...
- asked by Athis Startis (1 vote)
================================== Top new questions this week: ==================================
[Why does Mathematica results differ from C++ results within machine precision?] https://mathematica.stackexchange.com/questions/161716/why-does-mathematica-results-differ-from-c-results-within-machine-precision
I am trying to wrap my head around floating-point precision. Performing the following numeric operation:
275./6.*1.03692775514337
in Mathematica and C++ and taking the difference of the two results ...
- asked by Knowledge (22 votes), answered by ilian (44 votes)
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[Bug with Block & Lookup: Scope Variable Leak] https://mathematica.stackexchange.com/questions/161616/bug-with-block-lookup-scope-variable-leak
After debugging a large chunk of code, I could identify this MWE.
ClearAll@test test[var_String]:= Block[{association}, association = <|"x"-> <|"key01"-> "ok"|>|>[var]; ...
- asked by Murta (22 votes), answered by Albert Retey (15 votes)
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[Why is "k" in the output of Sum[Log[k]/k^k, {k,1,Infinity}]
?]
https://mathematica.stackexchange.com/questions/161704/why-is-k-in-the-output-of-sumlogk-kk-k-1-infinity
NSum[Log[k]/k^k, {k,1,Infinity}, WorkingPrecision->50] (* 0.219947267975228664843531307905860703797097130 *) But Sum[Log[k]/k^k, {k,1,Infinity}] (* -(PolyLog^(1,0))[0,1/k] *) What does "k" in ...
- asked by Vaclav Kotesovec (13 votes)
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[Simulating molecular dynamics efficiently] https://mathematica.stackexchange.com/questions/161471/simulating-molecular-dynamics-efficiently
The following website offers a very nice molecular dynamics simulation: http://physics.weber.edu/schroeder/md/. It is pretty neat and quite a few physical phenomena can be described from that small ...
- asked by anderstood (13 votes), answered by Henrik Schumacher (16 votes)
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[Why is listable not an attribute of the Set function?] https://mathematica.stackexchange.com/questions/161428/why-is-listable-not-an-attribute-of-the-set-function
The following is a list of attributes for the Set function:
Attributes[Set]
HoldFirst, Protected, SequenceHold
Why is Listable not included?
- asked by S.V (13 votes), answered by Kuba (16 votes)
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[How to improve quality of this Plot3D] https://mathematica.stackexchange.com/questions/161771/how-to-improve-quality-of-this-plot3d
I tried driving up PlotPoints and MaxRecursion but the intersections look weird, is there some other trick I can do?
plot = Plot3D @@ {Abs[Sqrt[x] + Sqrt[y]] /. {x -> Sin[2 x], y -> Cos[2 ...
- asked by Yaroslav Bulatov (10 votes), answered by Nasser (11 votes)
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[How can I tell Mathematica to interpret 0xffff as a hexadecimal number?] https://mathematica.stackexchange.com/questions/161646/how-can-i-tell-mathematica-to-interpret-0xffff-as-a-hexadecimal-number
I am stuck. I would like Mathematica simply accept 0x as a prefix Operator for Hexadecimal Numbers. I know that 0x is interpreted as 0*x, so maybe this is just not possible. I am a programmer and am ...
- asked by Mark (9 votes), answered by Carl Woll (16 votes)
================================== Greatest hits from previous weeks: ==================================
[Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts] https://mathematica.stackexchange.com/questions/19546/image-processing-floor-plan-detecting-rooms-borders-area-and-room-names-t
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The ...
- asked by s.s.o (52 votes), answered by nikie (52 votes)
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[How to create effect like Van Gogh’s stroke brush?] https://mathematica.stackexchange.com/questions/39003/how-to-create-effect-like-van-goghs-stroke-brush
I need to apply Van Gogh’s stroke brush effect to a random image
Take the following image as an example:
Thank you so much if you could help!
- asked by user10495 (30 votes), answered by Simon Woods (42 votes)
================================== Can you answer these? ==================================
[How to export graphics to SVG in script executed through cron?] https://mathematica.stackexchange.com/questions/161756/how-to-export-graphics-to-svg-in-script-executed-through-cron
I have a Wolfram script that generates plots, and exports them by evaluating expressions of the form
Export["/path/to/some.svg", myPlot];
The script works as intended when I run it from the [Unix] ...
- asked by kjo (3 votes)
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[Is it possible to prevent LUDecompositon from pivoting?] https://mathematica.stackexchange.com/questions/161552/is-it-possible-to-prevent-ludecompositon-from-pivoting
By construction LUDecomposition performs LU-decomposition with pivoting, i.e. with row permutations (otherwise the decomposition may not exist). Is it possible to tell Mathematica not to use pivoting ...
- asked by faleichik (1 vote)
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[How Many of R’s Functionalities Are Available From Inside Mathematica?] https://mathematica.stackexchange.com/questions/161664/how-many-of-rs-functionalities-are-available-from-inside-mathematica
When R is linked to Mathematica, how many of its functionalities are available from inside of Mathematica?
- asked by Glenford Mc Ewen (2 votes)
================================== Top new questions this week: ==================================
[Sharing small code snippets] https://mathematica.stackexchange.com/questions/161269/sharing-small-code-snippets
As part of my never-ending goal of getting Mathematica code to be as easily shared as python packages I was recently thinking about how to make code easy to share.
So what’s are some good ways to ...
- asked by b3m2a1 (19 votes), answered by b3m2a1 (13 votes)
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[InverseTotient[ ]?] https://mathematica.stackexchange.com/questions/160949/inversetotient
Maple has a function InverseTotient( c ), which returns all those natural numbers \(n\) whose Euler totient function \(\phi ( n ) = c\). Is there an equivalent inverse of EulerPhi[ ] in Mathematica? If ...
- asked by Joseph O’Rourke (11 votes), answered by Michael E2 (18 votes)
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[What are the counterparts in Wolfram to left and right division of a matrix in other programming language, e.g. Julia and MATLAB?] https://mathematica.stackexchange.com/questions/161301/what-are-the-counterparts-in-wolfram-to-left-and-right-division-of-a-matrix-in-o
Sometimes, to find the inverse of a matrix is a labor-consuming task or even "disgusting", especially when the matrix is "ill". It is said, e.g. in Julia, that the left/right division operation is ...
- asked by Alexander Zeng (10 votes), answered by C. E. (12 votes)
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[How to perform Loop subdivision on a triangle mesh with Mathematica?] https://mathematica.stackexchange.com/questions/161331/how-to-perform-loop-subdivision-on-a-triangle-mesh-with-mathematica
Every now and then, the question pops up how a given geometric mesh (e.g. a MeshRegion) can be refined to produce a i.) finer and ii.) smoother mesh. For example, the following triangle mesh from the ...
- asked by Henrik Schumacher (9 votes), answered by Henrik Schumacher (11 votes)
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[How to speed up ‘RotationMatrix‘?] https://mathematica.stackexchange.com/questions/161230/how-to-speed-up-rotationmatrix
I frequently run into the situation that I have to apply RotationMatrix to a huge bunch of 3D vectors and angles for numerical computations. On the one hand, the syntax of RotationMatrix forces me to ...
- asked by Henrik Schumacher (9 votes), answered by Henrik Schumacher (15 votes)
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[How to create (Header + Main area + Settings pane) notebook layout] https://mathematica.stackexchange.com/questions/161203/how-to-create-header-main-area-settings-pane-notebook-layout
cross-posted in community.wolfram.com
The goal is something like in the picture below.
Basic? I dare you to try to implement it in a manageable, scalable and flexible way.
Requirements:
The ...
- asked by Kuba (7 votes), answered by Mike Honeychurch (1 vote)
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[MaTeX and https://mathematica.stackexchange.com/questions/161219/matex-and-phantom
My understanding of the irective is that it should preserve the sizes of all elements in the expression. But when I try this:
m1 = Inset[MaTeX["\\sqrt{\\phantom{a^2}b}", Magnification -> ...
- asked by Wynne (7 votes), answered by Nasser (12 votes)
================================== Greatest hits from previous weeks: ==================================
[Elegant operations on matrix rows and columns] https://mathematica.stackexchange.com/questions/3069/elegant-operations-on-matrix-rows-and-columns
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
- asked by sjdh (148 votes), answered by Mr.Wizard (50 votes)
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[How to create effect like Van Gogh’s stroke brush?] https://mathematica.stackexchange.com/questions/39003/how-to-create-effect-like-van-goghs-stroke-brush
I need to apply Van Gogh’s stroke brush effect to a random image
Take the following image as an example:
Thank you so much if you could help!
- asked by user10495 (30 votes), answered by Simon Woods (42 votes)
================================== Can you answer these? ==================================
[Is there any code formatting style reference?] https://mathematica.stackexchange.com/questions/161344/is-there-any-code-formatting-style-reference
Is there any code formatting style reference for Wolfram Language similar to https://www.python.org/dev/peps/pep-0008/ and https://google.github.io/styleguide/javaguide.html? I’m teaching some people ...
- asked by qazwsx (4 votes)
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[Plot spectrum Fourier Transform] https://mathematica.stackexchange.com/questions/161381/plot-spectrum-fourier-transform
i want to plot the spectrum of the following function. I hope that anybody is able to help me. I don’t know how to plot the dirac delta function. I tried it this way but it didnťt work so far. Thanks! ...
- asked by Luke (1 vote)
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[Wrapper for mathematica code with GUI] https://mathematica.stackexchange.com/questions/160966/wrapper-for-mathematica-code-with-gui
I have a code written in Mathematica. What I am trying to do is to write a wrapper (say using Python) that will take user input for the Mathematica code, run the code, and create output.
I do not ...
- asked by CuriousCoder (2 votes)
================================== Top new questions this week: ==================================
[The fastest thing since sliced cubes?] https://mathematica.stackexchange.com/questions/160527/the-fastest-thing-since-sliced-cubes
I’ve fallen down a rabbit hole recently, and need a reality check.
Suppose you have an arbitrary unit vector, \(u \in \mathbf {R}^3\), and you cut up the unit cube into slices orthogonal to \(u\) with ...
- asked by aardvark2012 (18 votes), answered by ybeltukov (7 votes)
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[Mathematica does not respect linearity of integral] https://mathematica.stackexchange.com/questions/160655/mathematica-does-not-respect-linearity-of-integral
I have the following issue, trying to evaluate an integral. Mathematica tells me
Integrate[x^2 (1 + x^2)^(1/2) + y + z, {x, y, z} Sphere[{0, 0, 0}, 1]] (* 1/2 (3 Sqrt[2] - Log[2 (2 + Sqrt[2])]) ...
- asked by Simone Melchiorre Chiarello (14 votes), answered by Itai Seggev (8 votes)
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[How to obtain the cell-adjacency graph of a mesh?] https://mathematica.stackexchange.com/questions/160443/how-to-obtain-the-cell-adjacency-graph-of-a-mesh
Given an arbitrary mesh region, how can I efficiently obtain the graph describing the adjacency structure of mesh cells?
For example, given the following mesh,
SeedRandom[123] pts = RandomReal[1, ...
- asked by Szabolcs (10 votes), answered by Henrik Schumacher (11 votes)
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[Can a symbol have both OwnValues and DownValues?] https://mathematica.stackexchange.com/questions/160740/can-a-symbol-have-both-ownvalues-and-downvalues
Mathematica Version 11.2 desktop / Windows 10 Pro 64-bit
I am trying to understand if a symbol can have both OwnValues and DownValues.
Is this acceptable or not acceptable?
As an experiment, I ...
- asked by John (10 votes), answered by m_goldberg (11 votes)
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[Differences between DSolve and NDSolve] https://mathematica.stackexchange.com/questions/160560/differences-between-dsolve-and-ndsolve
I have a question about the difference in the solution between DSolve and NDSolve.
I want to solve the Friedmann equation of
\begin {align} 3\left (\frac {\dot {a}^2}{a^2}+\frac {k}{a^2}\right )=8\pi \end {align}
- asked by user85503 (10 votes), answered by Michael E2 (10 votes)
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[How to check if a vector is an eigenvector of a matrix using mathematica?] https://mathematica.stackexchange.com/questions/160801/how-to-check-if-a-vector-is-an-eigenvector-of-a-matrix-using-mathematica
Here is a vector
\[\begin {pmatrix}i\\7i\\-2\end {pmatrix}\]
Here is a matrix
$$\begin{pmatrix}2& i&0\\-i&1&1\\0 &1&0\end{pmatrix}$$
Is there a simple way to determine ...
- asked by Conor Cosnett (8 votes), answered by Michael E2 (5 votes)
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[How do I read values from photocells connected to analog pins of Arduino Uno?] https://mathematica.stackexchange.com/questions/160761/how-do-i-read-values-from-photocells-connected-to-analog-pins-of-arduino-uno
Generally, I need to connect my Arduino Uno to Mathematica and read 3 analog values from A0, A1, A2 in real-time.
As I understand, I have 2 ways of connecting Arduino to Mathematica:
First: I have a ...
- asked by Aleksandr Berezutskii (8 votes), answered by Suba Thomas (2 votes)
================================== Greatest hits from previous weeks: ==================================
[How to manipulate 2D plots?] https://mathematica.stackexchange.com/questions/7142/how-to-manipulate-2d-plots
When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...
- asked by István Zachar (124 votes), answered by István Zachar (142 votes)
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[How to find the position of elements in a list satisfying criteria] https://mathematica.stackexchange.com/questions/180/how-to-find-the-position-of-elements-in-a-list-satisfying-criteria
Say I have a list x={2,4,6,8,10} and I want to find out the positions of the elements that are greater than 7. Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
- asked by PeterR (47 votes), answered by J. M. (46 votes)
================================== Can you answer these? ==================================
[Default options of LinearSolve] https://mathematica.stackexchange.com/questions/160693/default-options-of-linearsolve
I would like to know what is the default options of LinearSolve when using LinearSolve[A,b], where A is a sparse matrix. There are several methods available such as Cholesky and Krysol etc., see here. ...
- asked by Wilhelm (1 vote)
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[Prevent Semi-Transparent Pixels in Export] https://mathematica.stackexchange.com/questions/160578/prevent-semi-transparent-pixels-in-export
I’ve noticed that when I export plots in Mathematica without a background, a lot of the text ends being made of semi-transparent pixels. For example:
myplot = ContourPlot[Cos[x] + Cos[y], x, 0, 4 ...
- asked by ereHsaWyhsipS (1 vote)
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[Identifying the range of the voice] https://mathematica.stackexchange.com/questions/160731/identifying-the-range-of-the-voice
I’m trying to do an equalization in an audio program called Audition.
To have a good voice equalization, I need to have a frequency range of my voice.
A minimum value and a maximum frequency value.
...
- asked by LCarvalho (2 votes)
================================== Top new questions this week: ==================================
[Is it possible to construct a fullform trace function] https://mathematica.stackexchange.com/questions/160184/is-it-possible-to-construct-a-fullform-trace-function
Is it possible to construct a FullFormTrace function that takes an arbitrary expression and prints a sequence (or returns a list) of the evaluation steps in full form. For instance
...
- asked by Bob Ueland (13 votes), answered by Edmund (15 votes)
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[Integrate gives wrong result for simple function] https://mathematica.stackexchange.com/questions/160278/integrate-gives-wrong-result-for-simple-function
(probably) Bug introduced in 9.0 or earlier and persisting through 11.2
It looks like this.
NIntegrate[1/(2 + Sin[x + y]), {x, 0, 2 Pi}, {y, 0, 2 Pi}] 22.7929 Integrate[1/(2 + Sin[x + y]), {x, 0, ...
- asked by huotuichang (10 votes), answered by Nasser (8 votes)
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[Select the same elements from lists] https://mathematica.stackexchange.com/questions/160222/select-the-same-elements-from-lists
I need a special intersectant operation for List other than Set.
There maybe some duplicate elements, also need to count instead of merging as Intersection.
For example:
...
- asked by GalAster (10 votes), answered by jjc385 (11 votes)
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[Building a convenient package distribution system] https://mathematica.stackexchange.com/questions/160330/building-a-convenient-package-distribution-system
The PacletManager is nice, but it’s not really a low-effort system to work with.
Installing a package can be made pretty easy, but only if the location from which it is to be installed makes it so.
...
- asked by b3m2a1 (8 votes)
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[How to merge two lists with different dimensions] https://mathematica.stackexchange.com/questions/160159/how-to-merge-two-lists-with-different-dimensions
I have two list, just like
a={a1,a2,a3,a4}; b={b1,b2,b3,b4,b5};
I want merge them and save to excel, as they have different dimention, so I want it have the following format.
...
- asked by zongxian (7 votes), answered by Carl Woll (12 votes)
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[What is the elegant way of applying function to two lists?] https://mathematica.stackexchange.com/questions/160028/what-is-the-elegant-way-of-applying-function-to-two-lists
I am interested in finding the most concise elegant way of doing the following: We have a function fun[x1,x2] and two lists:
ls1={a1,a2,a3,a4,......} and ls2={b1,b2,b3,b4,......}
I ...
- asked by qahtah (7 votes), answered by halirutan (11 votes)
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[Legend displaying the expected number of points per unit area next to density plot] https://mathematica.stackexchange.com/questions/160193/legend-displaying-the-expected-number-of-points-per-unit-area-next-to-density-pl
I have 2d points and want to show a colored density plot of them. I also want to display a legend showing which point density (number of points per unit area) the colors in the plot represent.
Let’s ...
- asked by mrz (6 votes), answered by C. E. (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating legends for plots with multiple lines?] https://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines
So I have a graph with multiple lists, for e.g.
data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have no way to generate a legend ...
- asked by Eiyrioü von Kauyf (63 votes), answered by Jens (92 votes)
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[What does # mean in Mathematica?] https://mathematica.stackexchange.com/questions/19035/what-does-mean-in-mathematica
I asked Mathematica to compute the following
Solve[c (1-x)^2-x^(1/4) == 0, x] and it returned this: x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 + 70 #1^4 c^4 - 56 #1^3 c^4 + 28 ...
- asked by ronanymous (21 votes), answered by Dr. belisarius (46 votes)
================================== Can you answer these? ==================================
[Convergent infinite sum fails to converge in Sum[...]] https://mathematica.stackexchange.com/questions/160280/convergent-infinite-sum-fails-to-converge-in-sum
It looks like this.
Limit[Sum[1/((2 n + 1) Pi I - x), {n, -m, m}], m -> ] = -(1/2) Tanh[x/2] Sum[1/((2 n + 1) Pi I - x), {n, -, }] Sum::div: Sum does not converge.
Turning on Regularization ...
- asked by huotuichang (1 vote)
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[Stacked BarChart with Callout] https://mathematica.stackexchange.com/questions/159945/stacked-barchart-with-callout
BarChart examples include this code :
BarChart[Table[Callout[RandomReal[{0, 1}], Unique["text"]], 2, 8], BarSpacing -> 2, ChartLayout -> "Stacked"]
Its result should be :
But I can’t ...
- asked by qwerty (2 votes)
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[Possible to add a Heading for the columns in HDF5 format?] https://mathematica.stackexchange.com/questions/159978/possible-to-add-a-heading-for-the-columns-in-hdf5-format
A similar post was found here, but it’s not using MMA.
A small test to export HDF5 file,
Export["test.h5", { "summary_Shoe" -> anssummary, "summary_Tie" -> anssummaryTie}]
Woks fine.
But ...
- asked by Chen Stats Yu (3 votes)
================================== Top new questions this week: ==================================
[Drawing Clifford Attractors in Mathematica] https://mathematica.stackexchange.com/questions/159668/drawing-clifford-attractors-in-mathematica
I came upon the "Clifford Attractor" today, which are equations of the form: \[x_{n+1}=\sin (a\ y_n) + c \cos (x_n)\] \[y_{n+1}=\sin (b\ x_n) + d \cos (y_n)\]
They create some incredible images by ...
- asked by TreFox (24 votes), answered by Szabolcs (32 votes)
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[Mismatch between Mathematica and COMSOL in 3D FEM problem] https://mathematica.stackexchange.com/questions/159506/mismatch-between-mathematica-and-comsol-in-3d-fem-problem
I would like to solve an advection-diffusion problem on a torus domain. There are three Dirichlet conditions: One at the inlet (concentration \(c=0\)), one at the outlet (\(c=0.5\)) and one at the wall ...
- asked by Alexander Erlich (16 votes)
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[Unexpected behaviors in built-in functions] https://mathematica.stackexchange.com/questions/159895/unexpected-behaviors-in-built-in-functions
Existence of this topic is discussed in this mathematica.meta post.
I’m sure I am not the only non-beginner in WL who from time to time finds themselves not being able to predict an outcome of a ...
- asked by Kuba (14 votes), answered by Kuba (6 votes)
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[How to create a faded image using an existing image file] https://mathematica.stackexchange.com/questions/159662/how-to-create-a-faded-image-using-an-existing-image-file
The question is simple:
How can I take an image of a perfect stamp (load an image file) such as
and make it look old, worn, and faded, with missing arbitrary small bits, like the following stamp
...
- asked by Vaggelis_Z (12 votes), answered by nikie (27 votes)
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[Building a Noisy Function] https://mathematica.stackexchange.com/questions/159614/building-a-noisy-function
Here’s a nice function with a nice plot:
f[t_] := Exp[-Abs[t]] Sin[t]; Plot[f[t], {t, -10, 10}, PlotRange -> All]
What I would like to do is to make it noisy... to add something to f[t] so ...
- asked by bill s (10 votes), answered by David G. Stork (9 votes)
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[Inaccurate (non-smooth) boundary of the mesh generated by ToElementMesh] https://mathematica.stackexchange.com/questions/159775/inaccurate-non-smooth-boundary-of-the-mesh-generated-by-toelementmesh
I try to generate a mesh over a region, which has a wavy boundary at its bottom and needs very fine mesh around the bottom.
However, the generated mesh boundary is not as smooth as the specified one. ...
- asked by Wilhelm (8 votes), answered by user21 (4 votes)
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[remove transparency of background Image] https://mathematica.stackexchange.com/questions/159837/remove-transparency-of-background-image
I have the following image:
As you can see the background is kind of white-ish. Now my question is: How can I remove this transperancy of the background image ?
- asked by totyped (8 votes), answered by Coolwater (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating Mathematica packages] https://mathematica.stackexchange.com/questions/29324/creating-mathematica-packages
I’m building a package to help me write packages and their documentation. In this post I explained how to make a package and its documentation. In the answer I provided I describe how to build a very ...
- asked by jmlopez (91 votes), answered by Leonid Shifrin (122 votes)
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[Difference between != and =!=] https://mathematica.stackexchange.com/questions/153694/difference-between-and
I (think I) understand the difference between == (semantic) and === (syntactic). So when comparing != and =!= I was expecting a similar difference. So can anyone explain why the third line in this ...
- asked by GambitSquared (6 votes), answered by John Joseph M. Carrasco (12 votes)
================================== Can you answer these? ==================================
[On comparable hardware, is Mathematica known to perform better in one operating system over the others?] https://mathematica.stackexchange.com/questions/159699/on-comparable-hardware-is-mathematica-known-to-perform-better-in-one-operating
Have any benchmarks been published by Wolfram Research to compare the performance of Mathematica in the major operating systems (Windows 10, Linux, MacOS)? If not, has anyone here performed such ...
- asked by Shredderroy (7 votes)
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[Adjusting opacity in map overlays] https://mathematica.stackexchange.com/questions/159843/adjusting-opacity-in-map-overlays
I am currently working with rainfall data from hurricane Harvey in order to better understand how to allocate resources in the event of another disaster. I want to accomplish a few things given this ...
- asked by Harrison Whorf (3 votes)
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[how to count or extract Cases out of list of association that matches pattern] https://mathematica.stackexchange.com/questions/159783/how-to-count-or-extract-cases-out-of-list-of-association-that-matches-pattern
I have list of associations
lr1 = {<|a -> {0,0}, b -> "TRUE"|>, <|b -> "FALSE", a -> {0,1}|>, <|a -> {1,0}, b -> "FALSE"|>, <|b -> "TRUE", a -> ...
- asked by Dragutin (4 votes)
================================== Top new questions this week: ==================================
[Automatic edX Pdf Handout creator] https://mathematica.stackexchange.com/questions/159065/automatic-edx-pdf-handout-creator
I am trying to make an automatic handout creator for my courses on edX. It took me a long time to do it...
(If you don’t know edX: https://www.edx.org/
I wrote a program that adds to each slide ...
- asked by totyped (14 votes), answered by M. Stern (4 votes)
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[The area of a unit disk is \(2\pi \)? (NIntegrate over a numerical region)] https://mathematica.stackexchange.com/questions/159194/the-area-of-a-unit-disk-is-2-pi-nintegrate-over-a-numerical-region
EDIT: The example below concerns the construction of a numerical region from a general boolean-valued function. The question of how to properly construct such a region has been answered below (by M. ...
- asked by Will.Mo (13 votes), answered by m_goldberg (12 votes)
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[How many Capitals are closer to me than my own?] https://mathematica.stackexchange.com/questions/159041/how-many-capitals-are-closer-to-me-than-my-own
A recent question in chat about "When you are in Aachen, Germany, five other countries capitals are closer than Berlin." triggered me to try to write something to find the cities automatically for ...
- asked by pH13 - Yet another Philipp (9 votes), answered by J. M. (4 votes)
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[How to SortBy Last and in Reverse order?] https://mathematica.stackexchange.com/questions/159295/how-to-sortby-last-and-in-reverse-order
I am looking at the two functions SortBy and ReverseSort.
SortBy[{{1, 2, 3}, {2, 3, 1}, {3, 1, 2}, {2, 2}}, Last] {{2, 3, 1}, {2, 2}, {3, 1, 2}, {1, 2, 3}}
How do I sort this by the ...
- asked by Chen Stats Yu (7 votes), answered by J. M. (7 votes)
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[CatalanNumber[-1] formula on functions.wolfram.com unequals result from Mathematica] https://mathematica.stackexchange.com/questions/159143/catalannumber-1-formula-on-functions-wolfram-com-unequals-result-from-mathemat
The formula for CatalanNumber[-1] on this functions.wolfram.com page gives: -(1/2) whereas CatalanNumber[-1] directly evaluated gives? -1
- asked by axelclk (7 votes), answered by J. M. (8 votes)
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[DiscretizeGraphics issues with transformations] https://mathematica.stackexchange.com/questions/159035/discretizegraphics-issues-with-transformations
I noticed DiscretizeGraphics does not work correctly with transformed Graphics such as
Graphics[Rotate[Rectangle[], 30ř]]
Both using Rotate and GeometricTransformation together with ...
- asked by Sascha (7 votes), answered by aardvark2012 (5 votes)
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[How to locate a stream line starting from a saddle point?] https://mathematica.stackexchange.com/questions/159093/how-to-locate-a-stream-line-starting-from-a-saddle-point
I read in a table of gradient vectors and plot using the ListStreamPlot. I want to locate and color the line that represents the "boundary" of the flux. A flux line that 1)starts from a saddle point ...
- asked by Jun Liu (6 votes)
================================== Greatest hits from previous weeks: ==================================
[What are the most common pitfalls awaiting new users?] https://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by Dr. belisarius (407 votes), answered by Michael E2 (238 votes)
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[Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts] https://mathematica.stackexchange.com/questions/19546/image-processing-floor-plan-detecting-rooms-borders-area-and-room-names-t
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The ...
- asked by s.s.o (52 votes), answered by nikie (52 votes)
================================== Can you answer these? ==================================
[Editing pdf files with Mathematica] https://mathematica.stackexchange.com/questions/159074/editing-pdf-files-with-mathematica
As an example, consider this pdf file.
Would it be possible to edit the pdf, such as removing a logo, the page numbering and even frames, and save the result as a pdf? I would like to keep the pdf ...
- asked by anderstood (4 votes)
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[A question concerning a generalization of HypergeometricPFQ] https://mathematica.stackexchange.com/questions/159242/a-question-concerning-a-generalization-of-hypergeometricpfq
I have been trying to find explicit formulas for the real and imaginary parts of the Wolfram function EllipticK. An interesting formula for the real part of EllipticK evaluated at a complex number is ...
- asked by John M. Campbell (1 vote)
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[Export cdf does not work in MathKernel command line] https://mathematica.stackexchange.com/questions/159210/export-cdf-does-not-work-in-mathkernel-command-line
I am using Mathematica through command line MathKernel. I am not trying to draw any graphics in the console. But I should be able to export things a CDF. Why can’t I export a CDF through command line ...
- asked by Neel Basu (2 votes)
================================== Top new questions this week: ==================================
[Implementing a planetary terrain generation algorithm] https://mathematica.stackexchange.com/questions/158843/implementing-a-planetary-terrain-generation-algorithm
From this (now deleted) question I found this site where the author discusses a simple technique for random terrain generation on a sphere.
The method discussed is as follows:
start with a ...
- asked by b3m2a1 (18 votes), answered by b3m2a1 (19 votes)
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[Performance of Select] https://mathematica.stackexchange.com/questions/158583/performance-of-select
I have a data set of about 4*10^6 3d-coordinates.
From this volume I am sequentially selecting coordinates along one axis and manipulating this subset.
My question: can the Select function be ...
- asked by mrz (15 votes), answered by kglr (23 votes)
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[Create a simple split tree] https://mathematica.stackexchange.com/questions/158858/create-a-simple-split-tree
I am trying to create a simple split tree.
The growth should be only upwards, the vertical element length constant (1), the size of the horizontal bars should be halved in each iteration and the ...
- asked by Niki (12 votes), answered by m_goldberg (10 votes)
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[Easy printing of executable code] https://mathematica.stackexchange.com/questions/158901/easy-printing-of-executable-code
I’m working on a package that has functions that call other existing and packaged functions. I’d like a way to output what some of those key calls are, so users can see what’s happening under the ...
- asked by Chris K (9 votes), answered by Szabolcs (10 votes)
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[Two bouncing balls in 1 dimension, issues with two different methods?] https://mathematica.stackexchange.com/questions/158857/two-bouncing-balls-in-1-dimension-issues-with-two-different-methods
I’m trying to simulate 2 balls with the same mass and diameter bouncing one on top of another under gravity, see the illustration below (not ideal, but this is the best result I’ve got so far, the ...
- asked by Yuriy S (8 votes), answered by b3m2a1 (7 votes)
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[Receive macOS notification when evaluation finishes] https://mathematica.stackexchange.com/questions/158898/receive-macos-notification-when-evaluation-finishes
Is Mathematica able to communicate with macOS’s native Notification Center in order to notify me if an evaluation finishes in any of my open notebooks?
I’m looking for a solution similar to this one ...
- asked by Casimir (8 votes), answered by Szabolcs (12 votes)
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[Why does repeated export of JPG-Images consume all memory?] https://mathematica.stackexchange.com/questions/158690/why-does-repeated-export-of-jpg-images-consume-all-memory
I was looking in the history of asked questions for similar questions, but none of the alike questions answered my problem sufficiently. So I ask nevertheless.
My system memory is leaked by simple ...
- asked by sacratus (8 votes)
================================== Greatest hits from previous weeks: ==================================
[Is it possible to draw this figure using Mathematica?] https://mathematica.stackexchange.com/questions/110848/is-it-possible-to-draw-this-figure-using-mathematica
The figure is
See the how-to video or a speeded-up GIF.
I believe it should be possible to draw this figure programmatically using some Random function, but I’m rather new to Mathematica, so I ...
- asked by AccidentalFourierTransform (62 votes), answered by M.R. (87 votes)
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[Elegant operations on matrix rows and columns] https://mathematica.stackexchange.com/questions/3069/elegant-operations-on-matrix-rows-and-columns
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
- asked by sjdh (147 votes), answered by Mr.Wizard (50 votes)
================================== Can you answer these? ==================================
[Number Formatting Functions Do Not Evaluate with ExportString] https://mathematica.stackexchange.com/questions/158694/number-formatting-functions-do-not-evaluate-with-exportstring
I need to export in a particular text file format and tried NumberForm, PaddedForm, AccountingForm, and DecimalForm to see which would work best. To my surprise only NumberForm evaluates when ...
- asked by Edmund (3 votes)
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[DSolve Throw::nocatch: Uncaught Throw[$Failed,balancefail] returned to top level. error in 11.2] https://mathematica.stackexchange.com/questions/158817/dsolve-thrownocatch-uncaught-throwfailed-balancefail-returned-to-top-level
Reported also to WRI. [CASE:3965533]
I am in the process of updating Kamke differentional equations tests for 11.2 when encountered a new error I have not seen before on one of the Kamke ODE’s ...
- asked by Nasser (3 votes)
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[Solve for several constants using a set of initial conditions] https://mathematica.stackexchange.com/questions/158783/solve-for-several-constants-using-a-set-of-initial-conditions
I have a set of differential equations that I am trying to solve for chemical reaction rate constants. So far I can get DSolve to solve the ODEs with initial conditions which provides the chemical ...
- asked by razzle_dazzle_84 (1 vote)
================================== Top new questions this week: ==================================
[Strange behavior of Table] https://mathematica.stackexchange.com/questions/158186/strange-behavior-of-table
Whenever I run the code
a = 0; code := (a++); Table[code; a, {1000}]
I get a list of 1000 zeros. However, if I replace 1000 with 100, then a get a list equal to Range[100]. Is this a bug or am I ...
- asked by Antonio De Juárez (12 votes), answered by Szabolcs (21 votes)
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[Large increase in integrate result leaf size after version 9. Looking for common cause] https://mathematica.stackexchange.com/questions/158059/large-increase-in-integrate-result-leaf-size-after-version-9-looking-for-common
reported to WRI. [CASE:3960295]
I run the CAS integration tests which contains 15000 integrals over number of Mathematica versions.
I found that the average leaf size of the anti-derivatives ...
- asked by Nasser (12 votes), answered by Itai Seggev (8 votes)
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[Convert Real packed array of pairs to Complex packed array] https://mathematica.stackexchange.com/questions/158082/convert-real-packed-array-of-pairs-to-complex-packed-array
I have a Real packed array arr. It may have arbitrary depth but Last@Dimensions[arr] == 2. For example, arr = N@Partition[Partition[Range[24], {2}], 3]
I want to convert it to a Complex packed ...
- asked by Szabolcs (12 votes), answered by Carl Woll (9 votes)
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[Conversion of Matrix of Characters to a Matrix of Zeros and Ones based on Column Frequency] https://mathematica.stackexchange.com/questions/158465/conversion-of-matrix-of-characters-to-a-matrix-of-zeros-and-ones-based-on-column
I have a matrix of characters that I wish to convert to a matrix of 0’ s and 1’ s. Although the matrix is large[17, 4301], I subsample this for purposes of my question. The matrix is:
m = {{"T", ...
- asked by Stuart Poss (11 votes), answered by Nasser (4 votes)
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[What’s the fastest way to take Mean of a Tensor in given slot?] https://mathematica.stackexchange.com/questions/158345/whats-the-fastest-way-to-take-mean-of-a-tensor-in-given-slot
One should expect that the implementation of the built-in function Mean was quick. However, as I recently observed, this is not true at all, in particular for matrices. Just compare Mean to the ...
- asked by Henrik Schumacher (9 votes), answered by Carl Woll (6 votes)
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[Animating a Potential Function (eigenfunctions of Laplace’s equation)] https://mathematica.stackexchange.com/questions/158412/animating-a-potential-function-eigenfunctions-of-laplaces-equation
I have written the following DynamicModule. The idea is that you can change the boundary, calculate the eigenfunctions and then animate them. Here is the code:
DynamicModule[{pts, bdr = {{0, 0}, {1, ...
- asked by Hugh (9 votes), answered by Kuba (8 votes)
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[How to implement a free version of WebImageSearch?] https://mathematica.stackexchange.com/questions/158134/how-to-implement-a-free-version-of-webimagesearch
I really don’t like functions that I have to pay for, if they can be implemented for free.
Is there a way to get around this pay-wall for WebImageSearch? Perhaps using some other free api or service? ...
- asked by M.R. (9 votes), answered by b3m2a1 (11 votes)
================================== Greatest hits from previous weeks: ==================================
[How to express trigonometric equation in terms of of given trigonometric function?] https://mathematica.stackexchange.com/questions/434/how-to-express-trigonometric-equation-in-terms-of-of-given-trigonometric-functio
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
Sin[x]^2+Cos[x]^2==1 Sin[x]/Cos[x]==Tan[x] ...
- asked by Prashant Bhate (27 votes), answered by Simon (34 votes)
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[Learn Mathematica (Wolfram) Language in one day] https://mathematica.stackexchange.com/questions/138366/learn-mathematica-wolfram-language-in-one-day
Currently I am trying to learn Python. Searching for relevant material I came across
X in Y minutes
and books with titles such as Learn Python in one day, in 24 hours, etc.
Similar material exists ...
- asked by dimitris (26 votes), answered by masterxilo (11 votes)
================================== Can you answer these? ==================================
[How to draw a generic 3D closed shape to be analyzed in AceFEM?] https://mathematica.stackexchange.com/questions/158446/how-to-draw-a-generic-3d-closed-shape-to-be-analyzed-in-acefem
I would like to draw a 3D shape to test my AceGen procedure. I will insert the AceFEM part of my code. In this example, I have performed the analysis on a hexahedron element.
- asked by M.Rock (2 votes)
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[Kernel crash with KeySelect and repeated keys on list of rules] https://mathematica.stackexchange.com/questions/158421/kernel-crash-with-keyselect-and-repeated-keys-on-list-of-rules
After running
KeySelect[{"a" -> 0, "a" -> 1}, True &]
my kernel either hangs forever (possibly with the eventual warning that "the kernel is not responding to a Dynamic evaluation") or ...
- asked by masterxilo (2 votes)
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[How to remove circled noise from image] https://mathematica.stackexchange.com/questions/158123/how-to-remove-circled-noise-from-image
Consider a simplified example:
noise
noise = Table[ RandomVariate[ NormalDistribution[1, 0.2]] Sin[Sqrt[x^2 + y^2]]^8, {x, -16, 16 - 16/512, 32/512}, {y, -16, 16 - 16/512, 32/512}];
...
- asked by xslittlegrass (3 votes)
================================== Top new questions this week: ==================================
[Is building an event-based parser possible/reasonable in Mathematica (WL)?] https://mathematica.stackexchange.com/questions/157834/is-building-an-event-based-parser-possible-reasonable-in-mathematica-wl
Too long? Go to Problems section
Background
I like to learn by doing small, sometimes artificial, projects. Among other things I had ’parsers’, and ’stream methods / streams in MMA’ on my to learn ...
- asked by Kuba (11 votes)
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[Test if a list is a constant integer multiple of another list] https://mathematica.stackexchange.com/questions/157783/test-if-a-list-is-a-constant-integer-multiple-of-another-list
I have a list of lists, and I want to eliminate all the lists that are constant integer multiples of another list. My initial approach was to divide the lists using nested tables.
ex1 = {{1, 1, 1}, ...
- asked by Lokdal (10 votes), answered by Mr.Wizard (9 votes)
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[Cannot Reproduce Answer to 99576] https://mathematica.stackexchange.com/questions/157889/cannot-reproduce-answer-to-99576
Bug introduced between versions 10.1 and 10.4, and persisting through 11.2. Reported to Wolfram, Inc as CASE:3958778.
Using either 11.2 or 10.4 on Windows 10 (64 bit), I am unable to reproduce the ...
- asked by bbgodfrey (9 votes)
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[Does ‘SeedRandom‘ give the same set of random numbers across operating systems?] https://mathematica.stackexchange.com/questions/157621/does-seedrandom-give-the-same-set-of-random-numbers-across-operating-systems
If I use
SeedRandom[12345] RandomReal[{0,1},100]
I get the same random numbers on two versions of Mathematica: 10.4.1.0 on Windows 10 and 11.1.1.0 on Windows 7.
But does the same seed get the ...
- asked by JimB (9 votes), answered by halirutan (8 votes)
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[Fill the data of an Association based on a list] https://mathematica.stackexchange.com/questions/157852/fill-the-data-of-an-association-based-on-a-list
Consider the following the list and association.
list1 = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10}; asc = <|1 -> a, 4 -> b, 7 -> c, 10 -> d|>;
I would like to create an association which ...
- asked by Anjan Kumar (7 votes), answered by Kuba (5 votes)
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[How to extract data points from two graphics and find the intersections between them?] https://mathematica.stackexchange.com/questions/157787/how-to-extract-data-points-from-two-graphics-and-find-the-intersections-between
I am working on a mathematical problem called "Buffon’s Needle". Here is the setup I made:
point[v_, u_] := Normalize[v - u] + u experiment50 = Show[ Graphics[ Table[{ RGBColor[0, 0, 0], ...
- asked by Anna Morales Melgares (7 votes), answered by kglr (7 votes)
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[How to thread over ragged list while skipping empty sub-lists?] https://mathematica.stackexchange.com/questions/157635/how-to-thread-over-ragged-list-while-skipping-empty-sub-lists
I have a very large ragged list result that is a list of list of pairs where sometimes the sub-list contains the empty list.
res = {{{20, 1}, {200, 2}}, {{}}, {{175, 1}}};
In the above minimal ...
- asked by Edmund (7 votes), answered by kglr (9 votes)
================================== Greatest hits from previous weeks: ==================================
[LaTeXand Mathematica] https://mathematica.stackexchange.com/questions/736/latex-and-mathematica
I quite often would like to draw graphics in my LaTeXdocuments using Mathematica. I have encountered three problems. I would like to know if there are any workarounds to these problems
I would ...
- asked by Thomas Rot (108 votes), answered by Simon (40 votes)
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[Code that generates a mandala] https://mathematica.stackexchange.com/questions/136974/code-that-generates-a-mandala
My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.
examples
- asked by zeros (48 votes), answered by Anton Antonov (71 votes)
================================== Can you answer these? ==================================
[Export BatchNormalizationLayer as MXNet] https://mathematica.stackexchange.com/questions/157856/export-batchnormalizationlayer-as-mxnet
I just tried to import a net from mathemtica into pythons using MXNet. It works fine with the following manual.
However, as soon as I try to add a BatchNormalizationLayer to my net MXNets bind() ...
- asked by MaxJ (3 votes)
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[ListPlot point colors by list of colorfunctions] https://mathematica.stackexchange.com/questions/157963/listplot-point-colors-by-list-of-colorfunctions
I would like to display the positions of a collection of particles as a function of time (animated) and color code them based on their velocities. For example, consider 10 particles moving in a 2D ...
- asked by SeanM (1 vote)
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[Why are Label Pixelated?] https://mathematica.stackexchange.com/questions/157693/why-are-label-pixelated
It seems that Mathematica implements the processing of labels quite different for different plot-functions.
The good -> Plot[]: l1 = GraphPlot[Table[i -> 1, {i, 0, 1}]] TPlot = Plot[{Cos[x], ...
- asked by Freeman (2 votes)
================================== Top new questions this week: ==================================
[How can I determine the type of a packed array?] https://mathematica.stackexchange.com/questions/157484/how-can-i-determine-the-type-of-a-packed-array
Packed arrays can be of type Integer, Real or Complex. Knowing that an array arr is packed, how can I efficiently determine its type?
- asked by Szabolcs (15 votes), answered by Szabolcs (17 votes)
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[Deleting sublists from lists] https://mathematica.stackexchange.com/questions/157267/deleting-sublists-from-lists
I have a list consisting of symbols and integers. I would like to delete the integers from the list only if a symbol precedes and follows each integer:
testList={a,b,3,c,4,5,d,e,f,1,g,4}
becomes:
...
- asked by Suite401 (12 votes), answered by jjc385 (13 votes)
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[Summation bug in 11.2] https://mathematica.stackexchange.com/questions/157290/summation-bug-in-11-2
If I sum all the positive-numbered Fourier coefficients of \(\cos (x)\), I get the correct answer. If I sum the negative-numbered ones, I get a wrong answer. Splitting the sum into two parts somehow ...
- asked by level1807 (10 votes), answered by Michael E2 (14 votes)
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[Calculating the size of objects in the picture] https://mathematica.stackexchange.com/questions/157374/calculating-the-size-of-objects-in-the-picture
I’m new to Wolfram Mathematica. I have an initial image:
My goal is to find a radius of the water drop, like so:
With that in mind, I’ve changed the initial photo:
resultImage = ...
- asked by Elias (9 votes), answered by b3m2a1 (7 votes)
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[Overlapping graphic primitives] https://mathematica.stackexchange.com/questions/157489/overlapping-graphic-primitives
I am trying to make a figure in Mathematica using some graphic primitives:
rod[l_, r_] := GraphicsGroup[{Opacity[.1], {Disk[{-l/2 + r, 0}, r, {\[Pi]/2 , 3 \[Pi]/2}]}, {Disk[{l/2 - r, 0}, r, ...
- asked by Ruud3.1415 (7 votes), answered by kglr (3 votes)
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[How can I implement my own documentation search function?] https://mathematica.stackexchange.com/questions/157303/how-can-i-implement-my-own-documentation-search-function
The current documentation search doesn’t allow for very sophisticate searching, can I write my own function to search through the docs?
- asked by b3m2a1 (7 votes), answered by b3m2a1 (8 votes)
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[Can I implement something like the old documentation help browser?] https://mathematica.stackexchange.com/questions/157317/can-i-implement-something-like-the-old-documentation-help-browser
Old versions of Mathematica had a help browser that was more click through and structured. How can I reimplement something like that for the new (since v6) docs?
- asked by b3m2a1 (6 votes), answered by b3m2a1 (10 votes)
================================== Greatest hits from previous weeks: ==================================
[What are the most common pitfalls awaiting new users?] https://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by Dr. belisarius (405 votes), answered by Michael E2 (235 votes)
—————————-
[How do I clear all user defined symbols?] https://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
- asked by niklasfi (58 votes), answered by Artes (56 votes)
================================== Can you answer these? ==================================
[Memoization of built in function] https://mathematica.stackexchange.com/questions/157429/memoization-of-built-in-function
What is the best way to let mathematica memoize built-in function like e.g.
SphericalHarmonicY[l,m,th,ph] One possibility would be for sure: sphericalHarmonicY[l_,m_,th_,ph_]:= ...
- asked by Mr Puh (3 votes)
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[Can’t import Gluon into mma] https://mathematica.stackexchange.com/questions/157466/cant-import-gluon-into-mma
This is a simple DNN from Fast, portable neural networks with Gluon HybridBlocks:
This is json file and params file of Gluon(MXNet)
import mxnet as mx from mxnet.gluon import nn print("mxnet ...
- asked by partida (4 votes)
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[NIntegrate and definite Integrate give different results] https://mathematica.stackexchange.com/questions/157300/nintegrate-and-definite-integrate-give-different-results
Suppose the function
f[x_,q_]=(15876 Exp[-0.527076 q^2] (x^2-2 x+2) SphericalBesselJ[1,5 q]^2 (q^2-8100 x^2))/(3425*Pi*q^5*x);
I need to perform the integration over q in the domain ...
- asked by John Taylor (1 vote)
================================== Top new questions this week: ==================================
[Frown for a sex change, or, how do I unbork the "FacialGender" classifier in 11.2?] https://mathematica.stackexchange.com/questions/156847/frown-for-a-sex-change-or-how-do-i-unbork-the-facialgender-classifier-in-11
The limits of machine learning. I thought the new "FacialGender" option for Classifier would be an amusing thing to explore.
So far, so good. But that’s me with bed-head. So let’s try a picture ...
- asked by Verbeia (17 votes), answered by Searke (2 votes)
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[Improve the mesh smoothing procedure] https://mathematica.stackexchange.com/questions/156611/improve-the-mesh-smoothing-procedure
My question is inspired by this answer about meshing with quadrilateral elements.
The following functions are my (naive) try of implementing the Laplacian smoothing. I find interior nodes in the mesh ...
- asked by Pinti (11 votes), answered by user21 (10 votes)
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[Possible bug in RegionUnion or related functions?] https://mathematica.stackexchange.com/questions/157031/possible-bug-in-regionunion-or-related-functions
Functions for derived geometric regions (RegionUnion and related) have been significantly updated in MMA 11.2 and now this simple example doesn’t work any more as expected. Could this be a bug or I am ...
- asked by Pinti (8 votes), answered by Szabolcs (5 votes)
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[Dataset - append row with a value which depends on two other rows] https://mathematica.stackexchange.com/questions/156980/dataset-append-row-with-a-value-which-depends-on-two-other-rows
I have go through the forum but did not see this question. Hope I don’t miss it.
I want to add a new colum "C" to a dataset with existing columns named "A" and "B". The value of "C" shall be the ...
- asked by Porty (7 votes), answered by WReach (6 votes)
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[How to tell Mathematica to do this with decimal part of real number?] https://mathematica.stackexchange.com/questions/156823/how-to-tell-mathematica-to-do-this-with-decimal-part-of-real-number
My apologies if this was asked here before.
My friend and I want to do this:
Suppose that we have some real number \(a. a_1 a_2...a_n...\) where \(a_i\) are digits in the set \(\{1,2,3,4,5,6,7,8,9,0\}\) ...
- asked by Antoine de Paladin (7 votes), answered by Edmund (6 votes)
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[FullForm of b/c and c/b with different order] https://mathematica.stackexchange.com/questions/156757/fullform-of-b-c-and-c-b-with-different-order
I am studying Mathematica myself and doing some exercises for improvement.
Question: Try to guess the internal forms of b/c and c/b. Verify your answer using FullForm.
Here is what I got by ...
- asked by anhnha (7 votes), answered by Mr.Wizard (6 votes)
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[Generate random walk on a graph] https://mathematica.stackexchange.com/questions/156626/generate-random-walk-on-a-graph
I have a graph with 100 nodes and 200 edges. How can I generate a random walk in it and animate it?
- asked by nasha amalina (7 votes), answered by rhermans (13 votes)
================================== Greatest hits from previous weeks: ==================================
[How to find the position of elements in a list satisfying criteria] https://mathematica.stackexchange.com/questions/180/how-to-find-the-position-of-elements-in-a-list-satisfying-criteria
Say I have a list x={2,4,6,8,10} and I want to find out the positions of the elements that are greater than 7. Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
- asked by PeterR (47 votes), answered by J. M. (45 votes)
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[How to calculate contour integrals with Mathematica?] https://mathematica.stackexchange.com/questions/34073/how-to-calculate-contour-integrals-with-mathematica
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
- asked by user64494 (30 votes), answered by Artes (53 votes)
================================== Can you answer these? ==================================
[How to decode Ascii85 format (AKA base85)?] https://mathematica.stackexchange.com/questions/156667/how-to-decode-ascii85-format-aka-base85
The ASCII85 encoding is a binary string encoding where every four bytes are encoded with five ASCII letters, using 85 different types of characters.
Unfortunately, it’s not in $CharacterEncodings:
...
- asked by M.R. (2 votes)
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[FIR filter and the relation between Sample rate and cut-off frequency] https://mathematica.stackexchange.com/questions/156685/fir-filter-and-the-relation-between-sample-rate-and-cut-off-frequency
I have problem to unterstand the logic of the cut-off frequency of the FIR filter. Suppose my sample rate is 2MHz and I want to design a lowpass filter with a cut-off frequency 100Hz. What will be ...
- asked by shabir barzanjeh (2 votes)
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[FindCluster only finds cluster "with a little help"] https://mathematica.stackexchange.com/questions/156984/findcluster-only-finds-cluster-with-a-little-help
Currently I made some slides to illustrate clustering. As an example I made a point set of two clusters:
{clusters, graph} = Block[{c1, c2, cluster1, cluster2}, c1 = {1, 2}; cluster1 = (# + ...
- asked by mgamer (4 votes)
================================== Top new questions this week: ==================================
[Finite element mesh not resolving features] https://mathematica.stackexchange.com/questions/156174/finite-element-mesh-not-resolving-features
I am trying to make a finite element mesh in 2D. The features are not found by ToElementMesh. This is a shelf bracket with nails. I build the region using RegionDifference and RegionUnion and the ...
- asked by Hugh (11 votes), answered by Young (9 votes)
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[Are the mail settings as given in preferences still programmatically accessible in V 11.2] https://mathematica.stackexchange.com/questions/156183/are-the-mail-settings-as-given-in-preferences-still-programmatically-accessible
In versions before 11.2 (and after 9) one could get the current settings as defined in the preferences (Internet & Email -> Mail Settings) with Options[SendMail]. As the options for SendMail have ...
- asked by Albert Retey (11 votes), answered by rhermans (9 votes)
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[Implement fractional Laplacian] https://mathematica.stackexchange.com/questions/156420/implement-fractional-laplacian
What is a way to implement the Fractional Laplacian with Mathematica?
How can we apply such implementation to numerically solve the problem
$$(-\Delta)^su = 1 \text{ in } B_1(0), \\ u = 0 \text{ in ...
- asked by Jay (9 votes), answered by Henrik Schumacher (14 votes)
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[Blur, GaussianFilter and ImageConvolve doesn’t work on some images] https://mathematica.stackexchange.com/questions/156210/blur-gaussianfilter-and-imageconvolve-doesnt-work-on-some-images
In versions 8.0.4 and 9.0.1 applying Blur to an image gives expected result:
img = Import["http://i.stack.imgur.com/UsJTa.png"] blurred = Blur[img, 5] ColorSeparate[blurred]
But ...
- asked by Alexey Popkov (9 votes), answered by Alexey Popkov (11 votes)
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[Error and uncertainty propagation: Is using Precision/Accuracy a sound strategy?] https://mathematica.stackexchange.com/questions/156481/error-and-uncertainty-propagation-is-using-precision-accuracy-a-sound-strategy
Questions
What are the available resources to deal with experimental error and uncertainty propagation in Mathematica? Given that Mathematica already uses linearized model of error propagation on ...
- asked by rhermans (8 votes)
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[Unexpected behavior using ‘ReplaceAll[]‘ for nested lists] https://mathematica.stackexchange.com/questions/156538/unexpected-behavior-using-replaceall-for-nested-lists
ReplaceAll[] might lead to unexpected behavior (at least it surprised me). I use ReplaceAll[] to convert a list (basically data cleanup). For the command: {{1, "2"}, {2, "3"}} /. {x_, _ } :> {x, ...
- asked by Dennis (7 votes), answered by Szabolcs (9 votes)
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[What are the possible Method option values for plotting functions?] https://mathematica.stackexchange.com/questions/156475/what-are-the-possible-method-option-values-for-plotting-functions
Many plotting functions have a Method options with descriptions like this:
Plot: "the method to use for refining curves" RegionPlot: "the method to use for refining regions" ContourPlot: "the method ...
- asked by Szabolcs (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How to perform a multi-peak fitting?] https://mathematica.stackexchange.com/questions/26336/how-to-perform-a-multi-peak-fitting
I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data ~ peak1 + peak2 + peak3).
The ...
- asked by Everett You (46 votes), answered by Silvia (47 votes)
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[How do I clear all user defined symbols?] https://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
- asked by niklasfi (55 votes), answered by Artes (54 votes)
================================== Can you answer these? ==================================
[Possible Symbolic Integration Bug] https://mathematica.stackexchange.com/questions/156215/possible-symbolic-integration-bug
Bug introduced between 5 and 8 and persisting through 11.2
I think I may have found a bug, and want to verify is this reproducible in other versions and platforms and not a mistake of mine.
I ...
- asked by yyli (5 votes)
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[Finding the slowest decay to a value for a 2D function] https://mathematica.stackexchange.com/questions/156338/finding-the-slowest-decay-to-a-value-for-a-2d-function
I have a function acf2[x,y] that describes the auto-correlation function of a simulated real surface, with a peak at the origin (acf2[0,0] = 1), and need to find the maximum distance from the origin ...
- asked by L.Todhunter (1 vote)
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[Can Mathematica run javascript on a website?] https://mathematica.stackexchange.com/questions/156377/can-mathematica-run-javascript-on-a-website
One way of running Javascript on a website is to use for instance Greasemonkey. By any chance, would it be possible to execute Javascript commands from Mathematica?
- asked by anderstood (1 vote)
================================== Top new questions this week: ==================================
[Pop-up appeared and then disappeared during first documentation search in 11.2] https://mathematica.stackexchange.com/questions/155717/pop-up-appeared-and-then-disappeared-during-first-documentation-search-in-11-2
After installing Mathematica 11.2, the first time I searched for something in the help center a pop-up appeared and then disappeared. It didn’t appear on a subsequent search, even if I restarted ...
- asked by Itai Seggev (23 votes), answered by Itai Seggev (26 votes)
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[ExternalEvaluate for Python fails with Import::nopythonevals] https://mathematica.stackexchange.com/questions/155821/externalevaluate-for-python-fails-with-importnopythonevals
I tried using ExternalEvaluate on OS X with Anaconda Python, and every ExternalEvaluate call failed with the Import::nopythonevals message. This happened even though an external evaluator was ...
- asked by Szabolcs (15 votes), answered by Szabolcs (12 votes)
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[Visualizing a holomorphic bijection between the unit disc and a domain] https://mathematica.stackexchange.com/questions/155954/visualizing-a-holomorphic-bijection-between-the-unit-disc-and-a-domain
One can construct a holomorphic bijection between the (open) unit disc \(D=\{z\in {\bf C}: |z|<1\}\), and a domain \(D\setminus \overline {B_{1/2}(-1/2)}\) where \(B_r(z_0)\) denotes the ball of radius \(r\) ...
- asked by Jack (12 votes), answered by Michael E2 (13 votes)
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[How to create search indices for custom documentation pages?] https://mathematica.stackexchange.com/questions/155932/how-to-create-search-indices-for-custom-documentation-pages
I have a package that uses custom documentation pages that are not generated with Wolfram Workbench.
How can I create search indices for these pages?
Requirements:
Searching should work in ...
- asked by Szabolcs (10 votes), answered by Szabolcs (1 vote)
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[Compile M11.1-compatible LibraryLink libraries using M11.2] https://mathematica.stackexchange.com/questions/155940/compile-m11-1-compatible-librarylink-libraries-using-m11-2
WolframLibraryVersion, defined in WolframLibrary.h, was bumped from 3 to 4 in Mathematica 11.2. This causes libraries compiled with M11.2 to fail to load in earlier versions.
Is it possible to ...
- asked by Szabolcs (9 votes)
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[How to insert dimensions in graphics?] https://mathematica.stackexchange.com/questions/155677/how-to-insert-dimensions-in-graphics
I’m creating figures (a T beam section) using the Graphics function. Like this:
a = Graphics[Polygon[{{0, 80}, {0, 85}, {100, 85}, {100, 80}}]]; b = Graphics[Polygon[{{47.5, 80}, {52.5, 80}, {52.5, ...
- asked by Diogo (9 votes), answered by wxffles (10 votes)
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[Mathematica 11.2 Import Statement Produces Errors & Truncates CSV Data Created in 11.1] https://mathematica.stackexchange.com/questions/155908/mathematica-11-2-import-statement-produces-errors-truncates-csv-data-created-i
Bug introduced in 11.2.0
TL;DR Issue 1 (bug): Import of CSV files with column specification fails when "HeaderLines" or "SkipLines" option is used: Import["ExampleData/financialtimeseries.csv", ...
- asked by Joseph Karpinski (8 votes), answered by Itai Seggev (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc] https://mathematica.stackexchange.com/questions/66273/how-to-tell-mathematica-that-certain-variables-are-real-imaginary-integer-value
I’m trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example,
u[x_] := Sqrt[2/L] * Sin[Pi * n * x / L]
and then ...
- asked by Matthew Brunetti (17 votes), answered by SquareOne (11 votes)
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[How do I clear all user defined symbols?] https://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
- asked by niklasfi (55 votes), answered by Artes (54 votes)
================================== Can you answer these? ==================================
[Covariant derivative given Christoffel symbols] https://mathematica.stackexchange.com/questions/155871/covariant-derivative-given-christoffel-symbols
I’ve been trying to take covariant derivative of various quantities along various surfaces in Mathematica, but I keep running into issues, frequently I get a tensor with the wrong dimension. Using the ...
- asked by Noahb32 (1 vote)
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[How to pass in-memory images through ExternalEvaluate?] https://mathematica.stackexchange.com/questions/156051/how-to-pass-in-memory-images-through-externalevaluate
Version 11.2 has a new import/export format PythonExpression.
Unfortunately, it doesn’t work out-of-the-box with images:
And using the ImageData directly is too slow:
Anyhow, I have some image ...
- asked by M.R. (4 votes)
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[GeneralizedLinearModelFit IRwLS] https://mathematica.stackexchange.com/questions/155692/generalizedlinearmodelfit-irwls
I’m interested in Mathematica’s capabilities with regard to robust fitting vs. outliers. In the Statistical Model Analysis Tutorial under the Generalized Linear Models section heading, there is this ...
- asked by Chris Chiasson (1 vote)
================================== Top new questions this week: ==================================
[Framework behind Graph plots. DynamicNamespace and friends] https://mathematica.stackexchange.com/questions/155237/framework-behind-graph-plots-dynamicnamespace-and-friends
As shown in DynamicLocation usage, we can use it to quickly create very nice functionality, that it to refer to graphics’ primitives relative coordinates without calculations of boundary etc.
As ...
- asked by Kuba (15 votes), answered by Kuba (12 votes)
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[DynamicLocation usage] https://mathematica.stackexchange.com/questions/155157/dynamiclocation-usage
Background
DynamicLocation can be very useful:
LocatorPane[Dynamic@x, Graphics[ { EdgeForm @ Thick, FaceForm @ None, Rectangle[BoxID -> "box"] , Arrow[{Dynamic[x], ...
- asked by Kuba (14 votes), answered by b3m2a1 (9 votes)
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[How can I use GitHub as a paclet server?] https://mathematica.stackexchange.com/questions/155123/how-can-i-use-github-as-a-paclet-server
I want to use GitHub as a paclet server, but this fails:
PacletInstall[ "ServiceConnection_StackExchange", "Site" -> "https:/github.com/b3m2a1/PacletServer" ] PacletSiteUpdate::err: An error ...
- asked by b3m2a1 (13 votes), answered by b3m2a1 (16 votes)
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[Permanently extending the behaviour of functions (like decorators)] https://mathematica.stackexchange.com/questions/155567/permanently-extending-the-behaviour-of-functions-like-decorators
Suppose I have a function, e.g.
f[x_] := x^2 It works like this: f[5] (* 25 *)
I would like to permanently modify it so that calling f[5] will perform some action before and after the evaluation ...
- asked by Szabolcs (11 votes), answered by Leonid Shifrin (9 votes)
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[Is Tooltip broken in MMA 11.1.1?] https://mathematica.stackexchange.com/questions/155434/is-tooltip-broken-in-mma-11-1-1
Bug introduced in 11.1.0 and persisting through 11.1.1
I have just discovered that Tooltip works differently from as described in the documentation, at least in my version of MMA (11.1.1.0, Windows ...
- asked by Oleg Soloviev (9 votes)
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[Install paclets into $BaseDirectory on multi-user system] https://mathematica.stackexchange.com/questions/155122/install-paclets-into-basedirectory-on-multi-user-system
PacletInstall will install paclets into the $UserBaseDirectory by default. How can we install them in $BaseDirectory so that all users on the system will have access? Is this currently possible?
...
- asked by Szabolcs (9 votes), answered by halirutan (5 votes)
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[How can I reproduce the result of PrincipalComponents] https://mathematica.stackexchange.com/questions/155467/how-can-i-reproduce-the-result-of-principalcomponents
matrix = N[{{1, 2}, {2, 3}, {4, 10}}] {{1., 2.}, {2., 3.}, {4., 10.}} res1 = PrincipalComponents[matrix, Method -> "Correlation"] {{1.10388, 0.130549}, {0.478746, -0.170139}, {-1.58262, ...
- asked by HyperGroups (8 votes), answered by J. M. (13 votes)
================================== Greatest hits from previous weeks: ==================================
[Labeling individual curves in Mathematica] https://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (52 votes), answered by Artes (40 votes)
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[What does # mean in Mathematica?] https://mathematica.stackexchange.com/questions/19035/what-does-mean-in-mathematica
I asked Mathematica to compute the following
Solve[c (1-x)^2-x^(1/4) == 0, x] and it returned this: x = Root[#1^8 c^4 - 8 #1^7 c^4 + 28 #1^6 c^4 - 56 #1^5 c^4 + 70 #1^4 c^4 - 56 #1^3 c^4 + 28 ...
- asked by ronanymous (20 votes), answered by Dr. belisarius (43 votes)
================================== Can you answer these? ==================================
[Question about RandomSeed option in AdaptiveMonteCarlo NIntegrate method] https://mathematica.stackexchange.com/questions/155249/question-about-randomseed-option-in-adaptivemontecarlo-nintegrate-method
I’ve been familiarising myself with the different options available in the AdaptiveMonteCarlo method for NIntegrate but one of the things that I can’t really understand is what the numbers correspond ...
- asked by user35305 (1 vote)
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[Delete duplicates in a list compiled of different lists and also delete] https://mathematica.stackexchange.com/questions/155261/delete-duplicates-in-a-list-compiled-of-different-lists-and-also-delete
I've got three lists: Lst1 has 100 different values for "r". Lst2 has 100 different values for "a". And Lst3=Pi*Lst1^2*Lst2. In Lst3 I've got duplicates and I want to get rid of them, but I also want ...
- asked by Cornelis (1 vote)
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[How to implement LinkLaunch-like functionality with timeout?] https://mathematica.stackexchange.com/questions/155493/how-to-implement-linklaunch-like-functionality-with-timeout
tl;dr: What is the best way (and correct sequence of operations) to connect two programs using MathLink while anticipating failures / timeouts?
Launch program and connect, with timeout
I have a ...
- asked by Szabolcs (4 votes)
================================== Top new questions this week: ==================================
[Finding \(n^{\text {th}}\) largest/smallest element] https://mathematica.stackexchange.com/questions/154944/finding-n-textth-largest-smallest-element
Ordering can quickly find the position of the largest/smallest element in a list, but finding the position of the \(n^{\text {th}}\) largest/smallest element is much slower:
data = RandomReal[10, 10^7];
...
- asked by Carl Woll (13 votes), answered by Carl Woll (12 votes)
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[Fast pairwise SameQ test of an ordered list] https://mathematica.stackexchange.com/questions/155017/fast-pairwise-sameq-test-of-an-ordered-list
I have an ordered list of \(N\) numbers, and I want to find out whether adjacent numbers are SameQ or not, returning a list of 0s and 1s of length \(N-1\). One approach is something like:
...
- asked by Carl Woll (11 votes), answered by jkuczm (8 votes)
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[Given an ordered set S, find the points in S corresponding to another list] https://mathematica.stackexchange.com/questions/154893/given-an-ordered-set-s-find-the-points-in-s-corresponding-to-another-list
Given a sorted list of numbers \(S\), I want to create a function that accepts a list of numbers \(L\) and for each number \(l \in L\) it returns the index of the largest number \(s \in S\) such that ...
- asked by Carl Woll (11 votes), answered by nikie (13 votes)
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[Geolocate multiple IP addresses] https://mathematica.stackexchange.com/questions/155076/geolocate-multiple-ip-addresses
I would like to geolocate a few hundred IP addresses (as part of analysing server logs). What is the best way to do this using Mathematica?
Does Mathematica have any builtin functionality for this?
...
- asked by Szabolcs (9 votes), answered by Szabolcs (9 votes)
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[How to connect two images] https://mathematica.stackexchange.com/questions/155093/how-to-connect-two-images
I have talk about how to catenate two images whose have same part totally in my this post.
But in this case two images have similar information, not totally same.
img1 = Import @ ...
- asked by yode (9 votes), answered by Kuba (8 votes)
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[Filter elements in descending order] https://mathematica.stackexchange.com/questions/154761/filter-elements-in-descending-order
I want to solve the following problem efficiently:
Given a list of pairs (value, data), I want to remove all the pairs so that the resulting list has the value property of its elements sorted. That ...
- asked by José D. (9 votes), answered by Mathe172 (9 votes)
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[Changing numbers inside list to a list] https://mathematica.stackexchange.com/questions/154911/changing-numbers-inside-list-to-a-list
I have a list wich contains numbers and other lists, and what I want is to change every number x to x,0.
So if the function I’m seeking is called f, then
a = {1,Pi,2+3I,{1,2},{3,4},-2} f[a] ...
- asked by Garmekain (8 votes), answered by John Joseph M. Carrasco (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Is it possible to draw this figure using Mathematica?] https://mathematica.stackexchange.com/questions/110848/is-it-possible-to-draw-this-figure-using-mathematica
The figure is
See the how-to video or a speeded-up GIF.
I believe it should be possible to draw this figure programmatically using some Random function, but I’m rather new to Mathematica, so I ...
- asked by AccidentalFourierTransform (62 votes), answered by M.R. (86 votes)
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[Can Mathematica do symbolic linear algebra?] https://mathematica.stackexchange.com/questions/3242/can-mathematica-do-symbolic-linear-algebra
For instance, is there some way I can say "let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ...
- asked by nikie (47 votes), answered by helen (25 votes)
================================== Can you answer these? ==================================
[Strange result for an improper integral \(\int _{0}^{1}\frac {x^{-1/2}}{e^{x}-1} \sin \left (\frac {1}{x}\right )dx\)] https://mathematica.stackexchange.com/questions/155066/strange-result-for-an-improper-integral-int-01-fracx-1-2ex-1-s
The improper integral \[\int _{0}^{1}\frac {x^{-1/2}}{e^{x}-1} \sin \left (\frac {1}{x}\right )dx\] is convergent conditionally.
(Applying Dirichlet Test, \[\frac {x^{-1/2}}{e^{x}-1}\] ...
- asked by user250236 (1 vote)
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[Perplexing simplification of RotationMatrix] https://mathematica.stackexchange.com/questions/154793/perplexing-simplification-of-rotationmatrix
The result of
FullSimplify[RotationMatrix[, {Cos[], Sin[], 0}], > 0].{0, 0, 1}
in Mathematica 11 is
{Sign[Sec[]]^2 Sin[] Sin[], -Cos[] Sin[], Cos[]}
instead of the nicer result ...
- asked by theindigamer (1 vote)
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[collecting terms with different order] https://mathematica.stackexchange.com/questions/154849/collecting-terms-with-different-order
I am using homotopy perturbation method to solve nonlinear ODE.
The first step is to introduce P parameter and collect different order of P.
The code is like this:
Collect[(1 - p) ((((1 + ...
- asked by sajad.sharhani (1 vote)
================================== Top new questions this week: ==================================
[Inserting some zeros in a list by a rule of positions] https://mathematica.stackexchange.com/questions/154551/inserting-some-zeros-in-a-list-by-a-rule-of-positions
I have a list:
mainlist={0.23, 0.34, 0.8, 0.0, -0.2, 0.4, -0.1};
I have to extend the above list to another one finalresult with Length=17. But in finalresult the elements of the mainlist must be ...
- asked by Inzo Babaria (12 votes), answered by John Joseph M. Carrasco (14 votes)
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[How to use Streaming package in v11.1?] https://mathematica.stackexchange.com/questions/154439/how-to-use-streaming-package-in-v11-1
I am trying to use the streaming package for lazy list operations demonstrated in this post. But I found that the package was significantly changed in version 11. After some observations, I found that ...
- asked by happy fish (11 votes), answered by Leonid Shifrin (9 votes)
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[Interior of discretized region] https://mathematica.stackexchange.com/questions/154544/interior-of-discretized-region
I have some domain of interest:
r = 0.3; dom = ImplicitRegion[(x - 1/2)^2 + (y - 1/2)^2 >= r^2, {{x, 0, 1}, {y, 0, 1}}];
Now I can extract mesh of the whole domain or just boundary:
...
- asked by user16320 (9 votes), answered by C. E. (10 votes)
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[Orientation of boundary domain normals] https://mathematica.stackexchange.com/questions/154656/orientation-of-boundary-domain-normals
I would like to use BoundaryNormals provided by the ElementMesh object. To demonstrate my problem I will take my favorite domain:
dom = ImplicitRegion[(x - 1/2)^2 + (y - 1/2)^2 >= (1/4)^2, {{x, 0, ...
- asked by user16320 (8 votes), answered by user16320 (4 votes)
—————————-
[Best Practices for Creating CDF e-textbook] https://mathematica.stackexchange.com/questions/154550/best-practices-for-creating-cdf-e-textbook
I attended a talk given by Eric Schulz a few years ago. It was similar to his talk "Sharing Wisdom Gained from Publishing a CDF Ebook" given here. I am Math instructor and have been creating ...
- asked by Michael McCain (8 votes)
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[Markdown parser in Mathematica] https://mathematica.stackexchange.com/questions/154634/markdown-parser-in-mathematica
Is there already a markdown to XML parser implemented in Mathematica? I wrote a one for my pelican rewrite, but realized I should have asked here first. Mine is almost certainly faulty in a few major ...
- asked by b3m2a1 (7 votes), answered by b3m2a1 (3 votes)
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[ListContourPlot with hatched regions] https://mathematica.stackexchange.com/questions/154481/listcontourplot-with-hatched-regions
I’m using ListContourPlot on a table of data, and I’d like to hash the regions rather than colour them, so the plot works in black and white.
data = Flatten[Table[{x, y, Cos[x] + Cos[y]}, {x, 0, 3, ...
- asked by KraZug (7 votes), answered by John Joseph M. Carrasco (8 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating legends for plots with multiple lines?] https://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines
So I have a graph with multiple lists, for e.g.
data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have no way to generate a legend ...
- asked by Eiyrioü von Kauyf (61 votes), answered by Jens (91 votes)
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[Learn Mathematica (Wolfram) Language in one day] https://mathematica.stackexchange.com/questions/138366/learn-mathematica-wolfram-language-in-one-day
Currently I am trying to learn Python. Searching for relevant material I came across
X in Y minutes
and books with titles such as Learn Python in one day, in 24 hours, etc.
Similar material exists ...
- asked by dimitris (26 votes), answered by masterxilo (11 votes)
================================== Can you answer these? ==================================
[NetTrain with External GPU?] https://mathematica.stackexchange.com/questions/154380/nettrain-with-external-gpu
I’d like to use the new Neural Networks functionalities in v11 on my Macbook Pro, unfortunately, most macs do not have the supported Nvidia cards. However, there is the option for using an external ...
- asked by M.R. (3 votes)
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[Solution (numerical or symbolic) of functional equations?] https://mathematica.stackexchange.com/questions/154515/solution-numerical-or-symbolic-of-functional-equations
Can I solve functional equations with Mathematica? How?
For example, I am trying to solve:
\[\frac {F(x)}{F(1)} = 2F\left (\frac {(1+x)^2}{4a}\right )-F(x/a)\]
for specific values of \(a\). Can ...
- asked by becko (1 vote)
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[Amplitude of a transfer function] https://mathematica.stackexchange.com/questions/154489/amplitude-of-a-transfer-function
I’m looking to calculate the amplitude of a transfer function which is defined in a symbolic way :
T=(1 + 2 I r )/(1 - r^2 + 2 I r ) I try this, i doesn't work Assuming[{ > 0, r > 0}, ...
- asked by Bendesarts (1 vote)
================================== Top new questions this week: ==================================
[Mathematica vs. Comsol for finite element analysis?] https://mathematica.stackexchange.com/questions/154254/mathematica-vs-comsol-for-finite-element-analysis
Being relatively new to finite element analysis, I was wondering how expert users assess Mathematica’s capabilities in solving PDEs via the finite element method compared to other commercial tools ...
- asked by Alexander Erlich (13 votes), answered by Alexei Boulbitch (7 votes)
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[Mathematica Syntax Coloring in GitHub README] https://mathematica.stackexchange.com/questions/153836/mathematica-syntax-coloring-in-github-readme
GitHub doesn’t auto-detect and color Mathematica code in its markdown. Can we make it do so?
This may be trivial, but many README files don’t seem to have it.
- asked by b3m2a1 (10 votes), answered by b3m2a1 (13 votes)
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[HoldPattern vs Unevaluated] https://mathematica.stackexchange.com/questions/153844/holdpattern-vs-unevaluated
For learning purposes I created this code:
{g, 3*(10 + g)} /. HoldPattern[Plus[t__]] :> (Plus[t] /. g -> h)
I am learning about HoldPattern. As I understand it HoldPattern makes sure that the ...
- asked by GambitSquared (8 votes), answered by Mr.Wizard (9 votes)
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[Who is to blame: parsing UTF8 encoded JSON HTTPResponse fails] https://mathematica.stackexchange.com/questions/154245/who-is-to-blame-parsing-utf8-encoded-json-httpresponse-fails
Background
V11.1.1 I’m using URLRead to fetch some data,
can’t show everything but headers contain:
"content-type->application/json; charset=utf-8"
and body (returned from URLRead) contains ...
- asked by Kuba (7 votes), answered by Alexey Popkov (5 votes)
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[Number elements in a list] https://mathematica.stackexchange.com/questions/153951/number-elements-in-a-list
I’m trying to learn more about list replacement without using Table. I have a list like this:
list = {{{"a", "b", "c"}, {"d", "e", "f"}, {"g", "h", "i"}}}
Now, I want to modify the list elements, ...
- asked by holistic (7 votes), answered by MarcoB (9 votes)
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[Fill a sphere above an arbitrary curve] https://mathematica.stackexchange.com/questions/153994/fill-a-sphere-above-an-arbitrary-curve
I have a function which generates a curve on the surface of a unit sphere, parameterised by the azimuthal angle. How can I plot a sphere with two different colour above and below this curve?
f[t_] := ...
- asked by Tom (6 votes), answered by Kuba (9 votes)
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[is it possible to change/customize some conversions done by TeXForm?] https://mathematica.stackexchange.com/questions/153876/is-it-possible-to-change-customize-some-conversions-done-by-texform
I use TeXForm to convert output of some computation to Latex. I’d like to ask if there is a way to override/change/customize some of these conversions, related to just the name Mathematica assigns to ...
- asked by Nasser (6 votes), answered by jkuczm (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How to manipulate 2D plots?] https://mathematica.stackexchange.com/questions/7142/how-to-manipulate-2d-plots
When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...
- asked by István Zachar (122 votes), answered by István Zachar (137 votes)
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[Mathematica erroneously says this integral does not converge] https://mathematica.stackexchange.com/questions/144965/mathematica-erroneously-says-this-integral-does-not-converge
Mathematica (as of v. 11.1.0) does not recognize that this special case of Frullani’s integral converges:
Integrate[(ArcTan[a*x] - ArcTan[b*x])/x, {x, 0, Infinity}] (* Integrate::idiv: Integral of ...
- asked by Pillsy (14 votes), answered by Michael E2 (20 votes)
================================== Can you answer these? ==================================
[Is there a good explanation of the output of FeatureExtract anywhere?] https://mathematica.stackexchange.com/questions/154044/is-there-a-good-explanation-of-the-output-of-featureextract-anywhere
I have been looking at the official documentation of FeatureExtract, and I’m having a bit of difficulty interpreting the output–or understanding the reasons for some of the choices that were made. ...
- asked by Shredderroy (1 vote)
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[How to work out sums symbolically?] https://mathematica.stackexchange.com/questions/153820/how-to-work-out-sums-symbolically
Intro
Consider these two equal expressions of the variance
\[\frac {\sum _{i=1}^n x(i)^2}{n}-\frac {\left (\sum _{i=1}^n x(i)\right ){}^2}{n^2}\]
and
$$\frac{\sum _{i=1}^n \left(x(i)-\frac{\sum ...
- asked by Remi.b (1 vote)
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[Expectation value of standard deviation] https://mathematica.stackexchange.com/questions/153848/expectation-value-of-standard-deviation
I was trying to calculate the expectation value of the standard deviation, if I only take two data points into account. My code is the following:
n[x_] = PDF[NormalDistribution[, ], x]; 2[x1_, ...
- asked by Glostas (1 vote)
================================== Top new questions this week: ==================================
[How to remove a paclet downloaded from Wolfram Research Server?] https://mathematica.stackexchange.com/questions/153752/how-to-remove-a-paclet-downloaded-from-wolfram-research-server
How can I remove a paclet that was automatically downloaded when I used a function for the first time (i.e. NetChain)?
I believe the download was faulty, preventing me from using any of the ...
- asked by mpourrah (8 votes), answered by Itai Seggev (10 votes)
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[Best way to expand vocabulary of Mathematica functions?] https://mathematica.stackexchange.com/questions/153469/best-way-to-expand-vocabulary-of-mathematica-functions
I’m enjoying slowly learning Mathematica but noticing one skill I’m lacking is a comprehensive vocabulary of Mathematica functions. I was wondering if members would mind sharing some strategies they ...
- asked by BBirdsell (8 votes), answered by Nasser (9 votes)
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[high pass filter without losing detail] https://mathematica.stackexchange.com/questions/153414/high-pass-filter-without-losing-detail
I have troubles doing a simple high pass filtering...
Downloading the test data https://pastebin.com/74J8t2YV as "test.dat", you can see that overimposed on the signal there are some low frequencies ...
- asked by alessandro (8 votes), answered by xzczd (7 votes)
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[Accesing keys based on position in an association] https://mathematica.stackexchange.com/questions/153689/accesing-keys-based-on-position-in-an-association
I would like to have the following simple function "GetKey[]" on a very large association.
(* The actual Association is very large, this is just small example *) assoc = <|{1,1} -> 2, {1,2} ...
- asked by Iconoclast (7 votes), answered by Carl Woll (9 votes)
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[How to calculate CellularAutomaton rule numbers in higher dimensions?] https://mathematica.stackexchange.com/questions/153388/how-to-calculate-cellularautomaton-rule-numbers-in-higher-dimensions
Where can I find documentation of the rule number convention for CellularAutomaton for higher than 1 dimension?
I understand the convention for elementary 1D automata, but I don’t understand even ...
- asked by Mark S. (7 votes), answered by Vitaliy Kaurov (6 votes)
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[Clicking on any Line of Code causes Plotted Points to Vanish] https://mathematica.stackexchange.com/questions/153368/clicking-on-any-line-of-code-causes-plotted-points-to-vanish
Bug detected in 11.1, apparently related but not identical to bug in 10.4. Reported to Worfram, Inc as CASE:3926732
$Version (* "11.1.1 for Microsoft Windows (64-bit) (April 18, 2017)" *) p1 = ...
- asked by bbgodfrey (7 votes), answered by John Joseph M. Carrasco (3 votes)
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[Puzzled about the behavior of NDSolve (ODE’s involving Integrals)] https://mathematica.stackexchange.com/questions/153624/puzzled-about-the-behavior-of-ndsolve-odes-involving-integrals
Any idea why NDSolve can easily handle the first of these examples, but not the 2nd? I have a system of ODE’s involving integrals without closed-form solutions, and keep getting the 2nd error message. ...
- asked by Andrea Wilson (6 votes), answered by Michael E2 (5 votes)
================================== Greatest hits from previous weeks: ==================================
[Labeling individual curves in Mathematica] https://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (52 votes), answered by Artes (40 votes)
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[Is there an open source implementation of Mathematica-the-language?] https://mathematica.stackexchange.com/questions/4454/is-there-an-open-source-implementation-of-mathematica-the-language
I’ve seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
- asked by sblom (88 votes), answered by Simon (68 votes)
================================== Can you answer these? ==================================
[Analysis of the periodic data by the maximum entropy method] https://mathematica.stackexchange.com/questions/153487/analysis-of-the-periodic-data-by-the-maximum-entropy-method
I am trying to get the frequency spectrum of a periodic data. Since the data set is short, the outcome of the frequency peaks are not sharp enough, which prevents me for further analysis. I know the ...
- asked by Phyman (1 vote)
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[Plotting InterpolationFunction over Quantities] https://mathematica.stackexchange.com/questions/153458/plotting-interpolationfunction-over-quantities
What’s the proper syntax to plot Interpolation functions defined over Quantities?
points = {{0, 0}, {1, 1}, {2, 3}, {3, 4}, {4, 3}, {5, 0}}; Change domain to Quantities: points2 = points // ...
- asked by alancalvitti (2 votes)
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[Fastest form of a function] https://mathematica.stackexchange.com/questions/153602/fastest-form-of-a-function
I’m trying to find the fastest form for a function. I have a few approaches with test results.The function I’m working with is the 3rd derivative of the incomplete beta function with respect to its ...
- asked by FalafelPita (1 vote)
================================== Top new questions this week: ==================================
[Why can’t I inject expressions in Compile using (only) With] https://mathematica.stackexchange.com/questions/153064/why-cant-i-inject-expressions-in-compile-using-only-with
Generally speaking, With can be used to inject into arbitrarily held expressions, for example:
With[{args = 2}, Hold @ Hold @ HoldComplete[args] ] (* Out[1]= Hold[Hold[HoldComplete[2]]] *) ...
- asked by glS (14 votes), answered by Leonid Shifrin (15 votes)
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[Why Mathematica can not factorize polynomials over algebraic fields?] https://mathematica.stackexchange.com/questions/152949/why-mathematica-can-not-factorize-polynomials-over-algebraic-fields
I noticed that a factorization over algebraic fields is useless in Mathematica. Here is the example over the field containing I*Sqrt[3]:
Pol=4 (3 I Sqrt[3] (-12 + 6 x - 4 x^2 + x^3) y^3 z + 9 (12 - ...
- asked by Aus Man (14 votes), answered by chyaong (11 votes)
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[RegionMeasure is wrong for simple 1D Path] https://mathematica.stackexchange.com/questions/153323/regionmeasure-is-wrong-for-simple-1d-path
Bug introduced in 11.1
Take the simple path defined by a line through a set of points
pts = {{0, 0}, {0, 1.5}, {0.05, 1.5}, {0.05, 0.5}, {0.1, 0.5}, {0.1, 1.5}, {0.15, 1.5}, {0.15, 0.5}, {0.2, ...
- asked by Sascha (13 votes), answered by Michael E2 (8 votes)
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[Why am I seeing what looks like a violation of operator precedence?] https://mathematica.stackexchange.com/questions/153258/why-am-i-seeing-what-looks-like-a-violation-of-operator-precedence
Why is it that when I evaluate
2*2.848529281693615`+3*-0.5155083247776808` I get (* -2.93688 *) which is wrong. 2*2.848529281693615` + (3*-0.5155083247776808`) (* 4.15053 *)
Any help would be ...
- asked by An old man in the sea. (9 votes), answered by C. E. (9 votes)
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[Need a gentle introduction to stylesheet writing] https://mathematica.stackexchange.com/questions/153102/need-a-gentle-introduction-to-stylesheet-writing
I have searched Mathematica.SE for stylesheet and found a lot of useful information on specific issues but no general introduction. There were 746 hits, and it is very time consuming for anyone to ...
- asked by m_goldberg (9 votes), answered by m_goldberg (7 votes)
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[Unexpected behavior when directly assigning to DownValues] https://mathematica.stackexchange.com/questions/152999/unexpected-behavior-when-directly-assigning-to-downvalues
I’m encountering some unexpected behavior when assigning to DownValues. When I assign two definitions for test[1] as below, Mathematica stores both definitions:
DownValues[test] = ...
- asked by tom (9 votes), answered by b3m2a1 (6 votes)
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[Except @ OptionsPattern[] affects OptionValue] https://mathematica.stackexchange.com/questions/152984/except-optionspattern-affects-optionvalue
The background
This example works as expected, small function with a special case rule:
foo // ClearAll foo // Options = {"bar" -> 1}; foo[x_, y : Except[_Rule], patt : OptionsPattern[] ...
- asked by Kuba (9 votes), answered by Mr.Wizard (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Mathematica 10.0.x freezes in Initializing kernels] https://mathematica.stackexchange.com/questions/92931/mathematica-10-0-x-freezes-in-initializing-kernels
Bug caused by paclet update and fixed by paclet update.
I updated to Windows 10 and have been running Mathematica fine on it for over a month. For some reason, it has just stopped working. I don’t ...
- asked by mitcheljh (73 votes), answered by ilian (95 votes)
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[Exporting graphics to PDF - huge file] https://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[], r Sin[], r^2}, {r, 0, ...
- asked by Matthew Leingang (94 votes), answered by Heike (80 votes)
================================== Can you answer these? ==================================
[Operator on a multivariable function in a sum] https://mathematica.stackexchange.com/questions/153092/operator-on-a-multivariable-function-in-a-sum
I need to define an operator that does as follow for any function \(h_m\).
$\qquad O[h_m](k,M,b,l_{max})=\sum_{l\neq (0,m)}^{l_{max}}il \left (h_l(k,M,b,l_{max}) b_{m-l}(k)- c_l\partial_k ...
- asked by Michael_J (1 vote)
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[Direct input in Chinese, Korean or Japanese] https://mathematica.stackexchange.com/questions/153042/direct-input-in-chinese-korean-or-japanese
Sometimes I need to create a document in Japanese: I know Mathematica supports typing in Japanese. However it doesn’t seem to support direct (inline) input in Japanese.
Whenever I need to convert a ...
- asked by Tadashi Kikuno (5 votes)
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[Parametric Plot of Faces] https://mathematica.stackexchange.com/questions/152909/parametric-plot-of-faces
In How do I draw a pair of buttocks? there is a discussion how to draw a human backside. It shows an example of Manipulate to ParametricPlot3D this part of a body.
In this discussion they were ...
- asked by Adalbert HanSSen (1 vote)
================================== Top new questions this week: ==================================
[String operation 1000X slower for special characters] https://mathematica.stackexchange.com/questions/152293/string-operation-1000x-slower-for-special-characters
It seems that the string operation is very slow if we have special characters in the string. Consider this example,
str = StringJoin@ RandomChoice[Join[Alphabet[], ToString /@ Range[0, 9]], ...
- asked by xslittlegrass (12 votes), answered by Alexey Popkov (12 votes)
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[Making a website with Mathematica] https://mathematica.stackexchange.com/questions/152663/making-a-website-with-mathematica
I know many people here have various websites associated with them and I’m guessing do at least some of the development of that stuff in Mathematica.
I recently fell down that rabbit hole myself, ...
- asked by b3m2a1 (11 votes), answered by C. E. (9 votes)
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[Convert association with list key to nested assocations] https://mathematica.stackexchange.com/questions/152676/convert-association-with-list-key-to-nested-assocations
I have an association that maps x, y pairs to values, for example:
<|{0, 0} -> "a", {-1, -4} -> "b", {-1, 1} -> "c", {-1, 0} -> "d", {1, 0} -> "e"|>
I want to convert this ...
- asked by 2012rcampion (9 votes), answered by MarcoB (8 votes)
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[Matching (y/x)^u
terms wherever the appear in an expression]
https://mathematica.stackexchange.com/questions/152559/matching-y-xu-terms-wherever-the-appear-in-an-expression
Mathematica keeps rewriting expressions, so it is hard to figure what pattern to use.
I am trying to replace all occurrences of \(\frac {y}{x}\) by \(t\), but Mathematica re-writes ...
- asked by Nasser (9 votes), answered by aardvark2012 (4 votes)
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[Bulletproofing packages against SetOptions of built-ins] https://mathematica.stackexchange.com/questions/152472/bulletproofing-packages-against-setoptions-of-built-ins
Packages are (obviously) written in terms of built-in Mathematica functions. But many (if not, most) of these functions have options, like Expand, Solve, Compile
While a package is active, the user ...
- asked by QuantumDot (9 votes), answered by Leonid Shifrin (12 votes)
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[How can I offset a curve from the given data points?] https://mathematica.stackexchange.com/questions/152298/how-can-i-offset-a-curve-from-the-given-data-points
I am new to Mathematica programming.
I have a question related to my work with this software.
I have the data points below:
{{128.011, 86.7748}, {128.011, 86.7748}, {128.167, 86.7663}, {128.19, ...
- asked by Mukidi Lee (8 votes), answered by J. M. (12 votes)
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[Export[..., "tsv"] drops minus signs from Dataset [horrific bug?]] https://mathematica.stackexchange.com/questions/152355/export-tsv-drops-minus-signs-from-dataset-horrific-bug
Toy example:
First, create a Dataset:
data = Dataset[{<|"x" -> 1, "y" -> -2|>, <|"x" -> -3, "y" -> 4|>}]
Next, export it as a TSV file:
...
- asked by kjo (8 votes), answered by Rolf Mertig (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Entering numbers in Scientific Notation?] https://mathematica.stackexchange.com/questions/36792/entering-numbers-in-scientific-notation
I need to play with a lot of powers such as 10^-3. 1E-3
does not work for it. Is there any
short form for it?
- asked by hhh (32 votes), answered by Rahul (43 votes)
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[Creating legends for plots with multiple lines?] https://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines
So I have a graph with multiple lists, for e.g.
data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have no way to generate a legend ...
- asked by Eiyrioü von Kauyf (60 votes), answered by Jens (90 votes)
================================== Can you answer these? ==================================
[Obstacle problem for the heat equation] https://mathematica.stackexchange.com/questions/152491/obstacle-problem-for-the-heat-equation
Consider the problem
$$\begin{cases} \max\{\Delta u -\partial_t u, \varphi - u \} = 0 & \text{ in } (0,T)\times \mathbb{R}^n \\ u(0,\cdot) = \varphi(0,\cdot) & \text{ in } \mathbb{R}^n. ...
- asked by Hiro (3 votes)
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[DateListPlot of multiple time series with data values and legend appearing as the cursor moves over ploted lines] https://mathematica.stackexchange.com/questions/152405/datelistplot-of-multiple-time-series-with-data-values-and-legend-appearing-as-th
This is very similar to my previous question. I want to use "DateListPlot" to visualize multiple time series (n) and see data values and legend as I move the cursor over plotted lines. To begin with, ...
- asked by ramesh (2 votes)
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[Using FindMinimum for a table of functions] https://mathematica.stackexchange.com/questions/152595/using-findminimum-for-a-table-of-functions
I am relatively new to Mathematica and am having trouble with my code running quite
slowly. What I am attempting to do is find the minimum value of a function (a chi^2
) of one
fit variable, but this ...
- asked by nsbd88 (1 vote)
================================== Top new questions this week: ==================================
[Reduce Code Length] https://mathematica.stackexchange.com/questions/152003/reduce-code-length
I have the following that works good, and computes in one shot,but the code is so long. Can someone please help me to reduce the size of this?
...
- asked by Bill W. (9 votes), answered by Ali Hashmi (7 votes)
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[Best way to handle nested Maps?] https://mathematica.stackexchange.com/questions/151742/best-way-to-handle-nested-maps
I often find myself working with lists of lists of data, gathering data, performing computations, and producing a variety of different sorts of output. Intuitively, it seems like this should be done ...
- asked by Michael Stern (9 votes), answered by eldo (6 votes)
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[Color gradient varying in a path] https://mathematica.stackexchange.com/questions/151980/color-gradient-varying-in-a-path
The code below is to create something like a logo. I want to apply a color gradient over the polygons of the pattern, but they vary along the path. The image that I want to approach is this:
ang = ...
- asked by LCarvalho (8 votes), answered by KennyColnago (9 votes)
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[Offset Partition with only one remainder element] https://mathematica.stackexchange.com/questions/152152/offset-partition-with-only-one-remainder-element
I would like to use a combination of options of Partition in a way that I can’t seem to find in the documentation.
Given example input {a,b,c,d,e,f,g}, I would like output ...
- asked by George Moore (7 votes), answered by kglr (4 votes)
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[Slot #
corresponding to subset of a list in select]
https://mathematica.stackexchange.com/questions/152082/slot-corresponding-to-subset-of-a-list-in-select
Is it possible to use # in the select function preserving the structure of the list? Here an example of what I mean. Let's say I want to select all the pairs where the first element is 1: data1 = ...
- asked by Fraccalo (7 votes), answered by kglr (7 votes)
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[Any faster approach than Outer for my computation] https://mathematica.stackexchange.com/questions/151892/any-faster-approach-than-outer-for-my-computation
Outer is slowing down considerably when the first argument is Abs[#1 - #2]/Max[#1, #2]& Outer[List, Range[5000], Range[5000]]; // AbsoluteTiming (* {0.120091, Null} *) Outer[Abs[#1 - ...
- asked by Ali Hashmi (6 votes), answered by nikie (9 votes)
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[How to generate password] https://mathematica.stackexchange.com/questions/151864/how-to-generate-password
I would like to generate a random password of a defined length which can easily be typed in with a standard keyboard.
As a start I tried the following:
SeedRandom["pass"]; ...
- asked by mrz (6 votes), answered by yohbs (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Why should I avoid the For loop in Mathematica?] https://mathematica.stackexchange.com/questions/134609/why-should-i-avoid-the-for-loop-in-mathematica
Some people advise against the use of For loops in Mathematica. Why? Should I heed this advice? What is wrong with For? What should I use instead?
- asked by Szabolcs (52 votes), answered by Szabolcs (62 votes)
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[Why round to even integers?] https://mathematica.stackexchange.com/questions/2116/why-round-to-even-integers
According to the Mathematica help:
Round rounds numbers of the form x.5 toward the nearest even integer.
For example:
Round[{0.5, 1.5, 2.5, 3.5, 4.5}] gives {0, 2, 2, 4, 4}
- asked by wxffles (64 votes), answered by Per Alexandersson (42 votes)
================================== Can you answer these? ==================================
[How can I exclude factors containing a certain symbol form matching my pattern] https://mathematica.stackexchange.com/questions/151971/how-can-i-exclude-factors-containing-a-certain-symbol-form-matching-my-pattern
Ok, I give up. I can’t figure how to tell Mathematica to do replacement using a pattern except for some special case. Easier to explain with small example.
I want to change pattern Exp[any_. c] to c ...
- asked by Nasser (3 votes)
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[Graphics3D with explicit ViewAngle inside Manipulate disappears for a moment when starting rotation] https://mathematica.stackexchange.com/questions/151978/graphics3d-with-explicit-viewangle-inside-manipulate-disappears-for-a-moment-whe
Given the following:
Manipulate[ ContourPlot3D[ x^4 + y^4 + z^4 - (x^2 + y^2 + z^2)^2 + 3 (x^2 + y^2 + z^2) == 3 c, {x, -3, 3}, {y, -3, 3}, {z, -3, 3}, ...
- asked by Mark (1 vote)
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[MTensor from existing memory?] https://mathematica.stackexchange.com/questions/151780/mtensor-from-existing-memory
I am wondering whether it’s possible to return a tensor from my C++ code using LibraryLink without copying the memory (because it’s large). So, instead of
libData->MTensor_new(..., &T0); ...
- asked by mrupp (2 votes)
================================== Top new questions this week: ==================================
[Is there concise code for the list operation I want to perform?] https://mathematica.stackexchange.com/questions/151550/is-there-concise-code-for-the-list-operation-i-want-to-perform
Is there any concise syntax for the following partitioning of a list. Given 1, 2, 3, 4, I want to get the output as shown below. I have tried various function such as Partition and others, but I ...
- asked by vikas (10 votes), answered by kglr (16 votes)
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[Animate Koch curve generation and include a transition effect] https://mathematica.stackexchange.com/questions/151621/animate-koch-curve-generation-and-include-a-transition-effect
Recently, I saw two kinds of animation of Koch curve iteration generation.
I don’t know how to make this effect, now I can only do this
Clear[koch]; koch[{A_, B_}] := Partition[ {A, (2 A ...
- asked by mathe (10 votes), answered by Kuba (14 votes)
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[How to find the sum for each individual row in a binary matrix until the first zero is reached from left to right.] https://mathematica.stackexchange.com/questions/151396/how-to-find-the-sum-for-each-individual-row-in-a-binary-matrix-until-the-first-z
I have a 150 by 300 binary matrix. I would like to sum the 1’s for each individual row
(from left to right) until the first zero is encountered. For example, if a given row is
1 1 1 1 1 1 0 0 0 1 0 0 ...
- asked by Tiffany Visgaitis (7 votes), answered by eldo (8 votes)
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[Replace element in array by checking condition in another list] https://mathematica.stackexchange.com/questions/151293/replace-element-in-array-by-checking-condition-in-another-list
Im trying to escape doing double loops given the large number of items in the arrays.
I have two list with a format like this:
list1={{1,2,0},{1,3,0},{4,6,0},{2,3,0}} (*Third element of each item is ...
- asked by Giovanni Baez (7 votes), answered by Carl Woll (8 votes)
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[Geometry computations add-on for Mathematica?] https://mathematica.stackexchange.com/questions/151304/geometry-computations-add-on-for-mathematica
I came across the problem of calculating the circumcenters of triangles symbolically within another algorithm (as well as possibly doing other similar geometry computations). I was hoping Mathematica ...
- asked by Grayscale (7 votes), answered by C. E. (10 votes)
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[Trace of the points of intersection of two moving curves] https://mathematica.stackexchange.com/questions/151325/trace-of-the-points-of-intersection-of-two-moving-curves
I would like to trace the points of intersection between the polar curves
r == Cos[n + k t] and r == t Csc[] as t goes from -1 to 1. (n and k are constants, and y, r, and relate in the ...
- asked by 404UserNotFound (6 votes), answered by Carl Woll (11 votes)
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[How to delete the parameter of a Neural Network?] https://mathematica.stackexchange.com/questions/151591/how-to-delete-the-parameter-of-a-neural-network
Mathematica Neural Networks based on MXNet. And there is lots of model in MXNet(MXNet Model Zoo).
For example,I follow a tutorial An introduction to the MXNet APIpart 4, It uses Inception v3(net ...
- asked by partida (5 votes), answered by xslittlegrass (3 votes)
================================== Greatest hits from previous weeks: ==================================
[Why should I avoid the For loop in Mathematica?] https://mathematica.stackexchange.com/questions/134609/why-should-i-avoid-the-for-loop-in-mathematica
Some people advise against the use of For loops in Mathematica. Why? Should I heed this advice? What is wrong with For? What should I use instead?
- asked by Szabolcs (52 votes), answered by Szabolcs (62 votes)
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[Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts] https://mathematica.stackexchange.com/questions/19546/image-processing-floor-plan-detecting-rooms-borders-area-and-room-names-t
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The ...
- asked by s.s.o (52 votes), answered by nikie (52 votes)
================================== Can you answer these? ==================================
[Unexpected Behavior of Parametric Sensitivity in ParametricNDSolveValue] https://mathematica.stackexchange.com/questions/151294/unexpected-behavior-of-parametric-sensitivity-in-parametricndsolvevalue
While exploring alternative methods of solving 33538, I encountered difficulties with the parametric sensitivity capability of ParametricNDSolveValue. (Useful background on parametric sensitivity is ...
- asked by bbgodfrey (2 votes)
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[FindShortestTour suddenly runs far slower for large numbers of points] https://mathematica.stackexchange.com/questions/151513/findshortesttour-suddenly-runs-far-slower-for-large-numbers-of-points
I was doing a benchmark of FindShortestTour and I noticed something really weird. Around 10000 points, FindShortestTour suddenly takes 6 times as long without explanation:
times = Table[ pts = ...
- asked by Jorge Perez (2 votes)
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[Manual CellGroups: problem with closing nested CellGroupData] https://mathematica.stackexchange.com/questions/151336/manual-cellgroups-problem-with-closing-nested-cellgroupdata
Background
CellGroupData second argument allows to specify which cells are visible. I faced problems though.
This example works well, the second group is not visible:
Notebook[{ Cell @ ...
- asked by Kuba (1 vote)
================================== Top new questions this week: ==================================
[Replace elements that do not match a pattern] https://mathematica.stackexchange.com/questions/149736/replace-elements-that-do-not-match-a-pattern
I have the following matrix
mat={{0,a,b},{c,0,d},{0,0,e}}
I would like to replace the zero elements of it with 1 and the remaining with zero. The first step would be
mat/.{0->1}
However I ...
- asked by Galuoises (12 votes), answered by eldo (7 votes)
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[Image segmentation by pixel value] https://mathematica.stackexchange.com/questions/149966/image-segmentation-by-pixel-value
I’m looking for a way to segment a grayscale image (or a 2D array) by its pixel values. We look at two neighboring pixels, if their values are close within a certain threshold, then we say they are ...
- asked by xslittlegrass (11 votes), answered by nikie (11 votes)
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[Can trees be made into graphs?] https://mathematica.stackexchange.com/questions/151155/can-trees-be-made-into-graphs
When one has the output of a function like TreeForm, for instance:
Can this be turned into a Graph object? I would like to be able to apply functions like VertexList, VertexDegree, AdjacencyList, ...
- asked by M. Brandt (8 votes), answered by C. E. (5 votes)
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[Layout tips to keep UI responsive] https://mathematica.stackexchange.com/questions/149835/layout-tips-to-keep-ui-responsive
Bug introduced in V10.4 or earlier and persisting through V11.1.1
CASE:3914402 Here is an example of a problem I have. Gutted version of something much bigger: handler2 = Framed[#, ...
- asked by Kuba (8 votes), answered by Kuba (1 vote)
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[How to use LaTeXin Mathematica text] https://mathematica.stackexchange.com/questions/151102/how-to-use-latex-in-mathematica-text
I would like to formulate a question in a notebook for my students using LaTeX(or MathML) to typeset functions and matrices. I specifically want a language other than Mathematica as students ...
- asked by user49947 (7 votes), answered by Nasser (6 votes)
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[getting zero for special positions in a matrix] https://mathematica.stackexchange.com/questions/149767/getting-zero-for-special-positions-in-a-matrix
There are a list
list={{1, 2, 3, 2, 3}, {3, 1, 1, 2, 3}, {3, 2, 1, 3, 2}, {1, 2, 1, 1, 1}}; I wish to have all elements be zero except the first and the fourth in each row: desired: list={{1, 0, ...
- asked by Irreversible (7 votes), answered by tomd (7 votes)
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[To Work with Barchart or DiscretePlot?] https://mathematica.stackexchange.com/questions/149960/to-work-with-barchart-or-discreteplot
I would like to create a graph similar to this below using some slightly dotted bar style like the one shown in the figure ...
And I’m trying to open a space between bars 6 and 8, but I’m failing.
...
- asked by LCarvalho (7 votes), answered by kglr (6 votes)
================================== Greatest hits from previous weeks: ==================================
[How to manipulate 2D plots?] https://mathematica.stackexchange.com/questions/7142/how-to-manipulate-2d-plots
When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...
- asked by István Zachar (117 votes), answered by István Zachar (134 votes)
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[Learn Mathematica (Wolfram) Language in one day] https://mathematica.stackexchange.com/questions/138366/learn-mathematica-wolfram-language-in-one-day
Currently I am trying to learn Python. Searching for relevant material I came across
X in Y minutes
and books with titles such as Learn Python in one day, in 24 hours, etc.
Similar material exists ...
- asked by dimitris (25 votes), answered by masterxilo (9 votes)
================================== Can you answer these? ==================================
[Sorting a list of rules] https://mathematica.stackexchange.com/questions/149862/sorting-a-list-of-rules
When we give several definitions for a function f, the DownValues of f are automatically sorted with respect to the domain defined by the pattern:
f[x_]:=2; f[x_?Positive] := 3; f[1]=4; ...
- asked by Fred Simons (3 votes)
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[Plotting orbits of trajectories of bodies sharing the earth’s orbit in coordinates centered at the barycenter of the solar system] https://mathematica.stackexchange.com/questions/151069/plotting-orbits-of-trajectories-of-bodies-sharing-the-earths-orbit-in-coordinat
I am attempting to try and plot the trajectories of a trio of satellites that are orbiting with the earth-moon system around the solar system’s barycenter. Originally, I had the satellites in orbit ...
- asked by SSoltero (1 vote)
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[Mathematica not releasing RAM] https://mathematica.stackexchange.com/questions/151127/mathematica-not-releasing-ram
The following code is supposed to sequentially read data from a large CSV file and put it row by row into an SQL server. Although I thought RAM consumption should be constant the system keeps asking ...
- asked by user13892 (2 votes)
================================== Top new questions this week: ==================================
================================== Top new questions this week: ==================================
[Is there a simple and fast way to delete dependent lines of a matrix] https://mathematica.stackexchange.com/questions/149281/is-there-a-simple-and-fast-way-to-delete-dependent-lines-of-a-matrix
I am building a matrix, but some of the lines are dependant. I would like to only keep independant lines (so erase all lines that depend from another).
I could compute the nullspace of the transpose ...
- asked by StarBucK (10 votes), answered by george2079 (10 votes)
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[Vertex coloring for bi-connected graphs] https://mathematica.stackexchange.com/questions/149247/vertex-coloring-for-bi-connected-graphs
In graph theory, a bi-connected component is a maximal bi-connected subgraph of a graph \(g\)–i.e., a connected subgraph that would remain connected if any one of its vertexes were to be removed. An ...
- asked by David G. Stork (10 votes), answered by kglr (9 votes)
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[Compile and uncompilable function bug?] https://mathematica.stackexchange.com/questions/149343/compile-and-uncompilable-function-bug
I think I found a bug, but I still have MMA version 11.0.1 installed. Can somebody please check if this persists in the latest version?
When I compile this function:
cf = Compile[{{n, _Integer}}, ...
- asked by JEM_Mosig (10 votes), answered by Michael E2 (12 votes)
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[How to make the result of InputForm balance the bracket] https://mathematica.stackexchange.com/questions/149558/how-to-make-the-result-of-inputform-balance-the-bracket
I always use InputForm to check the result object,such as Dataset or Graphics or other objects.But if you are in the result of InputForm,you cannot use the Front-End function of balance the bracket. ...
- asked by yode (9 votes), answered by Carl Woll (6 votes)
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[KeyValuePattern in matching and replacement in nested associations] https://mathematica.stackexchange.com/questions/149402/keyvaluepattern-in-matching-and-replacement-in-nested-associations
This case revealed I am missing something in pattern matching and evaluation in case of match, or I can’t grasp it due to the busy week I have. Either way, I find this problem interesting for wider ...
- asked by Kuba (9 votes), answered by Mr.Wizard (5 votes)
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[Align two images with respect to sperm head] https://mathematica.stackexchange.com/questions/149280/align-two-images-with-respect-to-sperm-head
My biologist friend has to align sperm images according to their heads. He usually does that manually by rotating each image. The problem is that there are so many images and it takes a lot of time. ...
- asked by Anjan Kumar (9 votes), answered by nikie (7 votes)
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[A more convenient Fourier series] https://mathematica.stackexchange.com/questions/149468/a-more-convenient-fourier-series
Personally, I feel the design of FourierSeries/FourierSinSeries/FourierCosSeries/FourierTrigSeries not convenient enough because:
They can’t give general formula of series as output, one must set a ...
- asked by xzczd (7 votes), answered by xzczd (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Why should I avoid the For loop in Mathematica?] https://mathematica.stackexchange.com/questions/134609/why-should-i-avoid-the-for-loop-in-mathematica
Some people advise against the use of For loops in Mathematica. Why? Should I heed this advice? What is wrong with For? What should I use instead?
- asked by Szabolcs (51 votes), answered by Szabolcs (61 votes)
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[My Girlfriend is going to prison...Save her with Math] https://mathematica.stackexchange.com/questions/135937/my-girlfriend-is-going-to-prison-save-her-with-math
Salacious title, but true story.
dmethyl1 = { {0, 0}, {.25, 1}, {.5, 7}, {1, 26}, {1.5, 40}, {2, 45}, {2.5, 45}, {3, 44}, {3.5, 44}, {4, ...
- asked by Prisoners Dilema (39 votes), answered by bobthechemist (24 votes)
================================== Can you answer these? ==================================
[Serious regression in Integrate in 11.1.1? Division by zero generated] https://mathematica.stackexchange.com/questions/149495/serious-regression-in-integrate-in-11-1-1-division-by-zero-generated
What is going on here? In version 11.1.1 on windows 7
Using Version 11.0.1 also on windows 7
Source code
ClearAll[x, n, c, a ,b] Integrate[(a + b*(c*x^n)^(2/n))^3, x]
Why does ...
- asked by Nasser (7 votes)
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[Hiding inputs with specific function] https://mathematica.stackexchange.com/questions/149298/hiding-inputs-with-specific-function
I believe this question could be a duplication, but I did some searches with the term "hide the input cell", but none answered me. Only inputs with this function.
I have several input cells using the ...
- asked by LCarvalho (3 votes)
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[Gravitational Lensing Simulation, Coordinate and Rendering Issues] https://mathematica.stackexchange.com/questions/149447/gravitational-lensing-simulation-coordinate-and-rendering-issues
I am trying to replicate this gravitational simulation online application called LensToy using Mathematica instead. I have two issues.
First, unlike LensToy, my rendering is extremely slow and drives ...
- asked by mpourrah (2 votes)
================================== Top new questions this week: ==================================
[Display 10^n
as power] https://mathematica.stackexchange.com/questions/148794/display-10n-as-power
How can I tell MMA to display input of the form 10^n
as \(10^n\) and not e.g. as 1000 for \(n = 3\) or the
rational \(\frac {1}{1000}\) for \(n = -3\).
This would help to keep tables compact when some ...
- asked by Casimir (13 votes), answered by eldo (10 votes)
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[How to remove unknown zero-width character from string?] https://mathematica.stackexchange.com/questions/148899/how-to-remove-unknown-zero-width-character-from-string
I have text that contains a zero-width character that I am not able to remove. A minimum example is in str below where the character is at the start of the text.
str = "4-6"; res = ToExpression /@ ...
- asked by Edmund (12 votes), answered by Carl Woll (10 votes)
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[Series sum approximation] https://mathematica.stackexchange.com/questions/149090/series-sum-approximation
Since there is no closed formula, as far as I know, to find the sum of
\[\sum _{n=2}^{\infty } \frac {(-1)^n}{\sqrt {\log (n)}}\]
I used //N to find an approximation and Mathematica gave me ...
- asked by Raffaele (11 votes), answered by TeM (18 votes)
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[How to extract first 9 rows from every block of 22 rows?] https://mathematica.stackexchange.com/questions/149026/how-to-extract-first-9-rows-from-every-block-of-22-rows
I’m working with a list of lists (a large table).
How would I extract the first 9 rows from every 22 rows of this list?
Essentially, I’d like to drop rows 10 to 22, and then 32 to 44, and so on, ...
- asked by musicmaker (11 votes), answered by C. E. (11 votes)
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[Confusion about HoldFirst attribute of Set] https://mathematica.stackexchange.com/questions/148956/confusion-about-holdfirst-attribute-of-set
Set has the attribute HoldFirst. Expectedly the following does not work, i.e. it does not assign the OwnValue of 3 to x:
In[1]:= {x, y}[[1]] = 3 During evaluation of In[1]:= Set::setps: {x,y} in the ...
- asked by kalix (8 votes), answered by Kuba (10 votes)
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[What algorithm is Mathematica using to find the smallest eigenvalue so quickly?] https://mathematica.stackexchange.com/questions/148759/what-algorithm-is-mathematica-using-to-find-the-smallest-eigenvalue-so-quickly
My question is what kind of black magic is Mathematica doing to obtain the correct answer so quickly compared to other programming languages?
Details:
I’ve written a Mathematica notebook to find the ...
- asked by Daniel Walsh (8 votes)
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[Simplify expression with Sqrt] https://mathematica.stackexchange.com/questions/149186/simplify-expression-with-sqrt
Hi folks I have a simple Simplify[] question
the following expression simplifies nice:
Sqrt[4 (a + b) - 4 c] // Simplify 2 Sqrt[a + b - c] the next one refuses Sqrt[4 (a + b) - 4 (c + d)] // ...
- asked by Robert Nowak (6 votes), answered by Shadowray (5 votes)
================================== Greatest hits from previous weeks: ==================================
[Calculate the 2D Fourier transform of an Image] https://mathematica.stackexchange.com/questions/29203/calculate-the-2d-fourier-transform-of-an-image
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase spectrum, as well as reconstruct the ...
- asked by user8727 (5 votes), answered by Nasser (27 votes)
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[Entering numbers in Scientific Notation?] https://mathematica.stackexchange.com/questions/36792/entering-numbers-in-scientific-notation
I need to play with a lot of powers such as 10^-3. 1E-3 does not work for it. Is there any short form for it?
- asked by hhh (32 votes), answered by Rahul (43 votes)
================================== Can you answer these? ==================================
[Cross-section of graph] https://mathematica.stackexchange.com/questions/148902/cross-section-of-graph
I am trying to use the following code to plot the cross-section of the graph z=x^2+y^2 and x=t. I use Manipulate to vary t. h = z - x^2 - y^2; g = x; Manipulate[ Show[ ContourPlot3D[{h == 0, g == ...
- asked by henryforever14 (1 vote)
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[How to embed Mathematica or Wolfram Alpha results in a website] https://mathematica.stackexchange.com/questions/149063/how-to-embed-mathematica-or-wolfram-alpha-results-in-a-website
Is it possible to dynamically embed responses into a blog post?
So the user would see:
There are 390900 plant species in the world.
With pseudo code:
There are #{worlfram(number of plant species)} ...
- asked by Mr. Demetrius Michael (1 vote)
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[Package MathWorld] https://mathematica.stackexchange.com/questions/148837/package-mathworld
I’m looking for MathWorld packages, but I can not find anywhere. I found an question that came very close but did not help me.
I got lost on the site and did not find anything.
I need to use the ...
- asked by LCarvalho (4 votes)
================================== Top new questions this week: ==================================
[Good references for parallel programming in Mathematica] https://mathematica.stackexchange.com/questions/148489/good-references-for-parallel-programming-in-mathematica
There are plenty of good references for all sorts of Mathematica programming:
This forum is a great example for specific questions/"getting things done". Books like those by R.Maeder (esp. the now ...
- asked by Gaius (17 votes)
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[Dot not well-defined: are there better examples?] https://mathematica.stackexchange.com/questions/148465/dot-not-well-defined-are-there-better-examples
Dot is not "well-defined" in Mathematica - we cannot simultaneously have it being associative and working with 1D and 2D arrays. For example, the order we substitute for variables should not change ...
- asked by mikado (10 votes), answered by Shadowray (9 votes)
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[Internal‘Bag memory usage] https://mathematica.stackexchange.com/questions/148594/internalbag-memory-usage
1. How does Internal‘Bag handle memory inside a compiled function? (examples below)
2. Is there a way to explicitly free up memory used by Internal‘Bag without exiting the function?
Preface: The ...
- asked by aardvark2012 (9 votes)
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[Preventing an unwanted vertical line from appearing my plot] https://mathematica.stackexchange.com/questions/148502/preventing-an-unwanted-vertical-line-from-appearing-my-plot
How can I eliminate (remove) the unwanted vertical line x = 1 when I make the plot shown below.
p3 = Plot[ {0.5/(-0.1 x + 0.1), 0.04/(-0.004 x + 0.004), 1.359/(-0.08 x + 0.08), ...
- asked by Irreversible (9 votes), answered by m_goldberg (1 vote)
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[Integer to Alpha Representation] https://mathematica.stackexchange.com/questions/148446/integer-to-alpha-representation
I wanted a nice way to convert natural numbers to alphabetic representations like:
1->"A", 2->"B", ... 26->"Z", 27->"AA, ... 26*2->"AZ", 26*2+1->"BA", ...
And I knew this was ...
- asked by b3m2a1 (8 votes), answered by Carl Woll (6 votes)
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[How to display numbers as multiples of a square root] https://mathematica.stackexchange.com/questions/148551/how-to-display-numbers-as-multiples-of-a-square-root
The extension field \(\mathbb {Q}(\sqrt {2} + \sqrt {3})\) can be represented by a \(4\) - dimensional vector space over \(\mathbb {Q}\) with basis \(\{1, \sqrt {2}, \sqrt {3}, \sqrt {6}\} \).
I made a matrix ...
- asked by nilo de roock (8 votes), answered by Carl Woll (7 votes)
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[Visually permute rows of a matrix via mouse dragging] https://mathematica.stackexchange.com/questions/148448/visually-permute-rows-of-a-matrix-via-mouse-dragging
I’m looking for a way to permute the rows of a matrix visually via mouse dragging, for example by clicking and dragging on a row in the MatrixPlot corresponding to the matrix.
What would be the best ...
- asked by glS (8 votes), answered by glS (10 votes)
================================== Greatest hits from previous weeks: ==================================
[How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc] https://mathematica.stackexchange.com/questions/66273/how-to-tell-mathematica-that-certain-variables-are-real-imaginary-integer-value
I’m trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example,
u[x_] := Sqrt[2/L] * Sin[Pi * n * x / L]
and then ...
- asked by Matthew Brunetti (17 votes), answered by SquareOne (11 votes)
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[Entering numbers in Scientific Notation?] https://mathematica.stackexchange.com/questions/36792/entering-numbers-in-scientific-notation
I need to play with a lot of powers such as 10^-3. 1E-3 does not work for it. Is there any short form for it?
- asked by hhh (32 votes), answered by Rahul (43 votes)
================================== Can you answer these? ==================================
[Which method should I use for a numerical triple Integration?] https://mathematica.stackexchange.com/questions/148629/which-method-should-i-use-for-a-numerical-triple-integration
Which method should I use for this numerical integration? Does it converge?
My constants are:
P = 10.5; m = 48.2; c = 1; = 0.01; V0 = 10; EE = 2.3; II = 1.; k = 68.9*10^3; My Integration is ...
- asked by Edmond Muho (2 votes)
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[possible memory problem with WatershedComponents] https://mathematica.stackexchange.com/questions/148318/possible-memory-problem-with-watershedcomponents
This could be regarded as a follow-up question to a previous post of mine (link).
When I use the WatershedComponents function on a large image (about 6000 x 10000 pixels) Mathematica comes up with an ...
- asked by Kardashev3 (4 votes)
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[Swedish characters in Databin] https://mathematica.stackexchange.com/questions/148550/swedish-characters-in-databin
I want to store strings with Swedish characters like å, ä and ö in a Databin, but get the following result:
bin = CreateDatabin[]; DatabinUpload[bin, {"a", "ä"}]; Values[bin] {a,"a""}
Does anyone ...
- asked by Sverker (5 votes)
================================== Top new questions this week: ==================================
[Same region, different meshes] https://mathematica.stackexchange.com/questions/148210/same-region-different-meshes
I’m playing around with ToElementMesh and I noticed the following behaviour that puzzles me. Consider the two regions
<< NDSolve`FEM` 1 = Polygon[{{-1/2, -1}, {-1/2, 1}, {1/2, 1}, {1/2, ...
- asked by Massimo Ortolano (11 votes), answered by user21 (9 votes)
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[Rearrange the list in a specific way] https://mathematica.stackexchange.com/questions/147876/rearrange-the-list-in-a-specific-way
Suppose I have a list like {"e", "c", "a", "d", "b"} and list of rules {1 -> 5, 2 -> 3, 3 -> 1, 4 -> 4, 5 -> 2}. The second list says that for example element on position 1 shoud be on ...
- asked by David Baghdasaryan (11 votes), answered by Shadowray (16 votes)
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[Self contained APIFunction. Collecting definitions] https://mathematica.stackexchange.com/questions/148207/self-contained-apifunction-collecting-definitions
Cross posted on community.wolfram.com
Background
After failed attempt (1) to create a complex API, by nicely linking my APIFunction to a cloud based package, I decided to go with the flow and trust ...
- asked by Kuba (10 votes), answered by Leonid Shifrin (4 votes)
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[Substitute some 1s with 0s in random list] https://mathematica.stackexchange.com/questions/148134/substitute-some-1s-with-0s-in-random-list
How is it better to substitute list of random combination of 1 and 0 (binary image) so that only first (or central) instance of 1 left in each group.
list = 0,1,1,0,0,1,0,1,1,1,0 should be ...
- asked by io_tuta (9 votes), answered by Carl Woll (10 votes)
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[Pattern matching Association in rules] https://mathematica.stackexchange.com/questions/148074/pattern-matching-association-in-rules
I would appreciate an explanation of how Associations behave in pattern matching, especially when matching rules, and using HoldPattern.
Consider the following:
assocRuleList = {<||> :> ...
- asked by ZeitPolizei (9 votes), answered by WReach (7 votes)
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[How to combine Neural Network and Audio like Classify?] https://mathematica.stackexchange.com/questions/148158/how-to-combine-neural-network-and-audio-like-classify
I want to combine Audio object and Neural Network ,first thing I remember is Classify
windInstrument = ExampleData[{"Sound", #}] & /@ {"AltoFlute", "AltoSaxophone", "BassClarinet", "BassFlute", ...
- asked by partida (8 votes)
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[ROT13 and upside-down text (flip text)] https://mathematica.stackexchange.com/questions/147829/rot13-and-upside-down-text-flip-text
How can we transform text in order to achieve ROT13 and flip text using Wolfram Mathematica?
1. ROT13
2. Flip text
- asked by rhermans (8 votes), answered by rhermans (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Mathematica 10.0.x freezes in Initializing kernels] https://mathematica.stackexchange.com/questions/92931/mathematica-10-0-x-freezes-in-initializing-kernels
Bug caused by paclet update and fixed by paclet update.
I updated to Windows 10 and have been running Mathematica fine on it for over a month. For some reason, it has just stopped working. I don’t ...
- asked by mitcheljh (73 votes), answered by ilian (94 votes)
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[1 Plot, 2 Scale/Axis] https://mathematica.stackexchange.com/questions/627/1-plot-2-scale-axis
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
- asked by 500 (115 votes), answered by ArgentoSapiens (110 votes)
================================== Can you answer these? ==================================
[How to improve the creation of tables of code and comments] https://mathematica.stackexchange.com/questions/148160/how-to-improve-the-creation-of-tables-of-code-and-comments
While writing a response to a certain MSE question I made a function that tabulates code and comments. (See the definition below.)
Here is an example:
code = " FoldList[(* reduction function *) ...
- asked by Anton Antonov (5 votes)
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[Export as HTML: Image of text is squished] https://mathematica.stackexchange.com/questions/147819/export-as-html-image-of-text-is-squished
When exporting a notebook to HTML, the notebook’s cells render as images, but the text is often squished. For example, this notebook:
... renders as
If I manually line-break the code, the ...
- asked by ConvexMartian (3 votes)
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[How to implement the same function use *Layer function?] https://mathematica.stackexchange.com/questions/148181/how-to-implement-the-same-function-use-layer-function
Reading YOLO method to detect object in the image(paper),I want to train this tiny-VOLO v1 on Mathematica,but the special loss function is very difficult to write.
Total loss is:
For brief,I use ...
- asked by partida (5 votes)
================================== Top new questions this week: ==================================
[List of symbols without built-in meaning] https://mathematica.stackexchange.com/questions/147328/list-of-symbols-without-built-in-meaning
Is there a list of all symbols with special display forms but no built-in meaning? That is, operators that are described in the tutorial Operators without Built-in Meanings?
- asked by Carl Woll (17 votes), answered by Carl Woll (17 votes)
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[Does Mathematica support deep links?] https://mathematica.stackexchange.com/questions/147374/does-mathematica-support-deep-links
So GitHub sent me on quite the journey, after it opened its desktop app from my browser.
Copying the link I found something looking like: "github-mac://...".
I spent the next like 15 minutes trying ...
- asked by b3m2a1 (12 votes), answered by b3m2a1 (12 votes)
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[How and why to use monadic programming in Mathematica?] https://mathematica.stackexchange.com/questions/147679/how-and-why-to-use-monadic-programming-in-mathematica
This is a methodological question with two parts:
How to use monadic programming in Mathematica?
and Why use monadic programming in Mathematica?
In my opinion the questions are inter-related – ...
- asked by Anton Antonov (10 votes)
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[Google Drive API connection: (or how can I build a service connection to an OAuth2 service?)] https://mathematica.stackexchange.com/questions/147451/google-drive-api-connection-or-how-can-i-build-a-service-connection-to-an-oaut
From here I know how to build a a basic service connection.
And that’s fine in simple authentication cases but how do I do this for OAuth services?
Even more specifically, how can I do this for ...
- asked by b3m2a1 (10 votes), answered by b3m2a1 (9 votes)
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[Performance of Nest vs. Do] https://mathematica.stackexchange.com/questions/147545/performance-of-nest-vs-do
When I am iterating the logistic function using a pure function, comparing Do and Nest:
x = 0.1; Do[x = 3 x (1 - x), 300] // RepeatedTiming Nest[3 # (1 - #) &, .1, 300] // RepeatedTiming
- asked by Stitch (9 votes), answered by Karsten 7. (9 votes)
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[Huge arrows in 3D graphics] https://mathematica.stackexchange.com/questions/147586/huge-arrows-in-3d-graphics
Hi. Consider the following code:
f1 = Plot3D[-Exp[-x^2-y^2],{x,-5,5},{y,-5,5},PlotRange->All] f2 = Graphics3D[Table[{Arrowheads[.01],Arrow[{{2Cos[i],2Sin[i],0},{2.5Cos[i], ...
- asked by AccidentalFourierTransform (9 votes), answered by Jens (9 votes)
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[Clean package update for API/FormFunctions on Wolfram Cloud] https://mathematica.stackexchange.com/questions/147330/clean-package-update-for-api-formfunctions-on-wolfram-cloud
Cross posted on community.wolfram.com (new comments)
TLDR
There is a pool of kernels/sessions available for each user, you don’t have control over the pool only over specific kernel you currently ...
- asked by Kuba (7 votes), answered by b3m2a1 (7 votes)
================================== Greatest hits from previous weeks: ==================================
[My Girlfriend is going to prison...Save her with Math] https://mathematica.stackexchange.com/questions/135937/my-girlfriend-is-going-to-prison-save-her-with-math
Salacious title, but true story.
dmethyl1 = { {0, 0}, {.25, 1}, {.5, 7}, {1, 26}, {1.5, 40}, {2, 45}, {2.5, 45}, {3, 44}, {3.5, 44}, {4, ...
- asked by Prisoners Dilema (37 votes), answered by bobthechemist (24 votes)
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[Creating legends for plots with multiple lines?] https://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines
So I have a graph with multiple lists, for e.g.
data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have no way to generate a legend ...
- asked by Eiyrioü von Kauyf (60 votes), answered by Jens (89 votes)
================================== Can you answer these? ==================================
[URLFetch parameters interfere with POST] https://mathematica.stackexchange.com/questions/147526/urlfetch-parameters-interfere-with-post
(orig: URLFetch Multipart POST fails to post Body?)
Update 2:
So after much weeping and gnashing of teeth our Lord and Savior Mathematica deemed me worthy of figuring out (some of) what the hell was ...
- asked by b3m2a1 (1 vote)
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[What is the best method for solving \(D(a,b,r,t)\) under a 5-minute computation time?] https://mathematica.stackexchange.com/questions/147520/what-is-the-best-method-for-solving-da-b-r-t-under-a-5-minute-computation-ti
Consider set \(\left \{\left . T(c,d)\right |c,d\in \mathbb {Z}\right \}\), a subset of rational numbers, where \(T(c,d)\) is a function.
I want to compute \(D(a,b,r,t)\)
...
- asked by Arbuja (1 vote)
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[Loop construction with multiple expressions for solving differential equation] https://mathematica.stackexchange.com/questions/147523/loop-construction-with-multiple-expressions-for-solving-differential-equation
I want to solve the following ODE.
\(H'' + \frac {2}{r}H'-\frac {\partial V_{eff}(H,r)}{\partial H}=0\)
with the following conditions
\(\frac {dH}{dr}(r=0)=0\) and \(H(r= \infty )=0\)
Regardless of the ...
- asked by Konstantinos (2 votes)
================================== Top new questions this week: ==================================
[Estimate the "Blurry" distribution of an image] https://mathematica.stackexchange.com/questions/146989/estimate-the-blurry-distribution-of-an-image
I’m trying to analyze an image obtained by scanning electron microscope(SEM) where different parts of the same image has has different blurring radius. My goal is to determine how blurry different ...
- asked by Wjx (17 votes), answered by Shadowray (20 votes)
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[Nest list with two functions] https://mathematica.stackexchange.com/questions/147055/nest-list-with-two-functions
Is it possible to use the NestList command with two functions, one at every even step and apply the other at every odd step. If this is possible could someone share an example ?
- asked by David (12 votes), answered by Shadowray (14 votes)
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[Exporting structured data to HDF5] https://mathematica.stackexchange.com/questions/146859/exporting-structured-data-to-hdf5
Sadly the documentation is lacking any useful examples on how to Export more complex data in HDF5. There is only
Export["file.h5",{expr1,...},{"Datasets", {"dataset1",...}}] creates an HDF5 file, ...
- asked by Sascha (10 votes), answered by Sascha (5 votes)
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[Using Mathematica to create an H-Tree] https://mathematica.stackexchange.com/questions/146797/using-mathematica-to-create-an-h-tree
Can folks show me several methods I can use to draw the following fractal H-Tree?
I did use Free-Form input, as:
= h-fractal
And got this image, which is three iterations, but no idea how it was ...
- asked by David (10 votes), answered by J. M. (10 votes)
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[Combining # & pure functions with post-fix notation
]
https://mathematica.stackexchange.com/questions/147132/combining-pure-functions-with-post-fix-notation
I can’t find the link anymore but there was a talk at a Wolfram conference (referencing v7 I think) where the authors highlight that stringing together functions like this:
Range[100] // ...
- asked by Joe (9 votes), answered by Szabolcs (7 votes)
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[Hosting a curated data function / server in Google Drive] https://mathematica.stackexchange.com/questions/146832/hosting-a-curated-data-function-server-in-google-drive
I want to make a curated data function, but I have no good place to store the paclets.
Per the pricing page I only get:
And that’s really not enough to host all of my data plus give me room to do ...
- asked by MB1965 (9 votes), answered by MB1965 (8 votes)
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[Interpolate the noisy data] https://mathematica.stackexchange.com/questions/146688/interpolate-the-noisy-data
I have some noisy data
data = Uncompress[FromCharacterCode[ Flatten[ImageData[Import["http://i.stack.imgur.com/RZcpj.png"],"Byte"]]]]
Plot looks like this
There is noise in certain region, ...
- asked by Saesun Kim (9 votes), answered by bill s (8 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating Mathematica packages] https://mathematica.stackexchange.com/questions/29324/creating-mathematica-packages
I’m building a package to help me write packages and their documentation. In this post I explained how to make a package and its documentation. In the answer I provided I describe how to build a very ...
- asked by jmlopez (89 votes), answered by Leonid Shifrin (114 votes)
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[How can I plot the direction field for a differential equation?] https://mathematica.stackexchange.com/questions/8841/how-can-i-plot-the-direction-field-for-a-differential-equation
I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...
- asked by Matt Groff (20 votes), answered by Peter Breitfeld (17 votes)
================================== Can you answer these? ==================================
[How to replace all instances of a number throughout my entire cell] https://mathematica.stackexchange.com/questions/146971/how-to-replace-all-instances-of-a-number-throughout-my-entire-cell
I have a cell where for several instances throughout I label certain functions, strings, and ranges using a similar pattern so as to follow through with integration calculations, list forming, and ...
- asked by yalev (3 votes)
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[Error occurred while connecting to remote kernel.Can’t use dynamic] https://mathematica.stackexchange.com/questions/146823/error-occurred-while-connecting-to-remote-kernel-cant-use-dynamic
When Open Mathematica using remote kernel,it throws LinkConnect error. But normal command can evaluate.Like Range@5,$Version... But Can't use dynamic.It throws An unknown box name. So if I want to ...
- asked by partida (4 votes)
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[Partition an Image automatically Based on Borders] https://mathematica.stackexchange.com/questions/146837/partition-an-image-automatically-based-on-borders
I would like to be able to train a model to recognize the borders in a newspaper image and then partition those into separate Images. Images similar to this would be the input Image
And then ...
- asked by Avadhut Bhosarekar (2 votes)
================================== Top new questions this week: ==================================
[PerformanceGoal option ignored in V11.1] https://mathematica.stackexchange.com/questions/146214/performancegoal-option-ignored-in-v11-1
Bug introduced in 11.1
[CASE:3892079] was created
[...] I have reproduced this problem with PerformanceGoal in version 11.1 and reported the issue to our developers [...]
Take this code:
...
- asked by Kuba (14 votes), answered by Kuba (15 votes)
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[Can I build my own curated data function?] https://mathematica.stackexchange.com/questions/146220/can-i-build-my-own-curated-data-function
I love the huge curated datasets, but they don’t cover everything. I have my own huge dataset which is too much to distribute as an EntityStore so is there a way to build my own analog of, say, ...
- asked by MB1965 (13 votes), answered by MB1965 (16 votes)
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[Support for low-complexity (compressible) lists] https://mathematica.stackexchange.com/questions/146244/support-for-low-complexity-compressible-lists
By "low-complexity list" I mean a list like the following:
lcl = {17, 17, 17, 17, 17, 21, 21, 21, 21, 21, 21, 21, 21, 11, 11, 11, 11, 11, 11, 11}
It contains 20 elements, but only 3 ...
- asked by kjo (10 votes), answered by Mr.Wizard (6 votes)
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[Automating documentation generation] https://mathematica.stackexchange.com/questions/146670/automating-documentation-generation
Outside of kernel symbols Mathematica provides access to lots of usage info, e.g. DownValues, Options, Messages, etc.
Most languages, if given this sort of info, would be able to provide an automatic ...
- asked by MB1965 (9 votes), answered by MB1965 (10 votes)
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[Trace of -1 expression] https://mathematica.stackexchange.com/questions/146506/trace-of-1-expression
I’m trying to understand Trace. Usually it doesn’t repeat but it adds -1,-1 for his simple expression after having a correct result.
-{1}//Trace {-1, {-1}, {-1, -1}, {-1}} Why -{1}//Trace is ...
- asked by io_tuta (9 votes), answered by Michael E2 (7 votes)
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[How to import a Tensorflow model?] https://mathematica.stackexchange.com/questions/146216/how-to-import-a-tensorflow-model
I’ve trained a network in Tensorflow and have the checkpoint files, I’d like to if anyone has written a parser or importer to pull the evaluation graph and/or weights into Mathematica?
- asked by user5601 (9 votes)
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[intersection between two 2D arrays with labeled data is slow] https://mathematica.stackexchange.com/questions/146558/intersection-between-two-2d-arrays-with-labeled-data-is-slow
Here is how to Generate data
the function is below with two images to generate data
img1 img2 segmentImage[binarizedMask_?ImageQ] := Module[{seg, areas, indexMaxarea, maxArea}, seg = ...
- asked by Ali Hashmi (8 votes), answered by Carl Woll (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Exporting graphics to PDF - huge file] https://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[], r Sin[], r^2}, {r, 0, ...
- asked by Matthew Leingang (92 votes), answered by Heike (80 votes)
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[Generating a Sierpinski carpet] https://mathematica.stackexchange.com/questions/22052/generating-a-sierpinski-carpet
I am trying to draw a Sierpinski_carpet. I have code that works, but I think there is a more elegant way to do than my way. Maybe I couls use Tuples or Permutations or some similar function to ...
- asked by chyaong (46 votes), answered by Mr.Wizard (75 votes)
================================== Can you answer these? ==================================
[Exporting graphics with VertexColors problem] https://mathematica.stackexchange.com/questions/146306/exporting-graphics-with-vertexcolors-problem
I’ve generated a graphics which exhibit gradient color in rectangle and export it as:
SetDirectory[NotebookDirectory[]]; Export["./test.pdf", Graphics[{Polygon[{{-4, 5/3}, {-4, 0}, {4, 0}, {4, ...
- asked by RoderickLee (3 votes)
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[How to imitate the opacity plot in EditColorFunction] https://mathematica.stackexchange.com/questions/146623/how-to-imitate-the-opacity-plot-in-editcolorfunction
I wish to imitate the opacity plot as shown below:
Edit2: (ref: https://www.wolfram.com/mathematica/new-in-9/3d-volumetric-image-processing/edit-color-function-palette-for-image3d.html)
Here is ...
- asked by Majis (3 votes)
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[Possible bug in Export with CharacterEncoding -> "PrintableASCII"] https://mathematica.stackexchange.com/questions/146294/possible-bug-in-export-with-characterencoding-printableascii
In the Documentation we read (emphasis is mine):
By default, the Wolfram System uses the character encoding "PrintableASCII" when saving notebooks and packages. This means that when special ...
- asked by Alexey Popkov (4 votes)
================================== Top new questions this week: ==================================
[Mathematica stuck in "running" for every calculation I attempt, kernel error] https://mathematica.stackexchange.com/questions/146005/mathematica-stuck-in-running-for-every-calculation-i-attempt-kernel-error
Bug caused by paclet update and fixed by paclet update.
I downloaded Mathematica this morning to do an implicit polar plot. I attempt to run the code
Manipulate[ ContourPlot[ Evaluate@With[{r = ...
- asked by 0celouvskyopoulo7 (26 votes), answered by ilian (16 votes)
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[How to split data into clusters based on fitting to function] https://mathematica.stackexchange.com/questions/146079/how-to-split-data-into-clusters-based-on-fitting-to-function
I have data which looks somewhat like this:
On the picture, you can see that the data can be described by 2 linear functions - if you manage to split it into 2 groups, each can easily be fitted ...
- asked by Arsen Zahray (10 votes), answered by rhermans (11 votes)
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[Inserting cones at intersection points two curves] https://mathematica.stackexchange.com/questions/145874/inserting-cones-at-intersection-points-two-curves
I am plotting the null geodesics for a Schwarzschild surface in Schwarzschild coordinates and would light to insert small future light-cones at the points of intersection to emphasize the tipping over ...
- asked by Soof_fie (9 votes), answered by rhermans (3 votes)
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[How to define a function inside a Compile?] https://mathematica.stackexchange.com/questions/145931/how-to-define-a-function-inside-a-compile
I want to compile a variety of commands, including a function. I need to map this function, inside the compilation, and I can’t include the function without facing errors such as ...
- asked by user5253864 (9 votes), answered by xzczd (10 votes)
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[How to automatically do a computation, Quit[], restart and do a new computation] https://mathematica.stackexchange.com/questions/145852/how-to-automatically-do-a-computation-quit-restart-and-do-a-new-computation
Related questions have been asked before (eg Where does a package have to be loaded?, http://stackoverflow.com/questions/6152023/quit-kernel-in-mathematica-by-a-command-not-using-evaluation-menu
- asked by Gaius (9 votes), answered by Shadowray (6 votes)
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[1D transient heat equation problem with controller] https://mathematica.stackexchange.com/questions/145799/1d-transient-heat-equation-problem-with-controller
I would appreciate some help with following issue:
I am trying to solve a 1D transient heat equation problem with a control loop in order to compensate a time variable boundary condition at one ...
- asked by daklems (9 votes), answered by user21 (6 votes)
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[Clarify when to use Style vs Directive vs List] https://mathematica.stackexchange.com/questions/145856/clarify-when-to-use-style-vs-directive-vs-list
I am confused about when to use a simple list of style options, the Directive function or the Style function.
As shown below, for simple situations at least, they seem entirely equivalent which ...
- asked by Joe (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to manipulate 2D plots?] https://mathematica.stackexchange.com/questions/7142/how-to-manipulate-2d-plots
When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...
- asked by István Zachar (115 votes), answered by István Zachar (131 votes)
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[Where can I find examples of good Mathematica programming practice?] https://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (463 votes), answered by faysou (411 votes)
================================== Can you answer these? ==================================
[Unexpected behavior of a variable] https://mathematica.stackexchange.com/questions/145661/unexpected-behavior-of-a-variable
I am confused with a strange phenomenon that I observe and do not understand.
Look, here is a simple code making a random walk:
Clear[list]; list = Accumulate[RandomInteger[{-1, 1}, {10, 2}]]
- asked by Alexei Boulbitch (2 votes)
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[How can I disable system updates only?] https://mathematica.stackexchange.com/questions/146133/how-can-i-disable-system-updates-only
Suppose I’m quite happy with my current Mathematica installation and wish to keep the system in its current form just reliably working.
Since there were already at least two cases[1,2] when a lot of ...
- asked by Alexey Popkov (7 votes)
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[Import/export manipulate state in file] https://mathematica.stackexchange.com/questions/146017/import-export-manipulate-state-in-file
Is it possible to export the state of Manipulate with big number of parameters in file and then restore the parameters of Manipulate from this file?
- asked by (3 votes)
================================== Top new questions this week: ==================================
[Count works differently depending on how an association was created] https://mathematica.stackexchange.com/questions/144813/count-works-differently-depending-on-how-an-association-was-created
Bug introduced in 10.4 and persisting through 11.1.1
I create two associations, that are supposed to be exactly the same. And then I want to count the elements at the second level. And I get ...
- asked by Stitch (19 votes), answered by WReach (12 votes)
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[Why is Plus so much slower than Total?] https://mathematica.stackexchange.com/questions/145019/why-is-plus-so-much-slower-than-total
Why is Plus so much slower than total for summing lists?
list = RandomReal[1, 10000000]; AbsoluteTiming[Plus @@ list] AbsoluteTiming[Total[list]] Output: {1.67408, 5.00073*10^6} {0.00570379, ...
- asked by Jorge Perez (14 votes), answered by Shadowray (17 votes)
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[Delete duplicates from list of lists as if on a necklace] https://mathematica.stackexchange.com/questions/144696/delete-duplicates-from-list-of-lists-as-if-on-a-necklace
Given a list of lists of integers, all of the same length, I want to regard two elements as equivalent if one is the rotated and/or reflected version of another (that is, if the two lists are the same ...
- asked by rogerl (13 votes), answered by Shadowray (13 votes)
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[Exchanging numpy arrays between Python and Mathematica?] https://mathematica.stackexchange.com/questions/144770/exchanging-numpy-arrays-between-python-and-mathematica
I've been using np.savetxt(location, result, delimiter=',') in Python followed by Import[location,"CSV"] in Mathematica. Some of my files are around 1GB, opening seems a bit slow, what else do people ...
- asked by Yaroslav Bulatov (12 votes), answered by xslittlegrass (16 votes)
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[How to plot planar graphs in a visually pleasing way?] https://mathematica.stackexchange.com/questions/144594/how-to-plot-planar-graphs-in-a-visually-pleasing-way
Cross posted to Wolfram Community
Mathematica has a layout algorithm to plot planar graphs without edge crossings. This typically produces an ugly triangular layout where some vertices and edges ...
- asked by Szabolcs (11 votes), answered by Szabolcs (6 votes)
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[Where are my Cloud Credits going?] https://mathematica.stackexchange.com/questions/144859/where-are-my-cloud-credits-going
In less than a month I've used 5k cloud credits (half of my quota) and all I did was deploying a bunch of static notebooks with CloudDeploy[CurrentNotebook[],permissions->Public] (more ...
- asked by Yaroslav Bulatov (10 votes)
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[Mathematica erroneously says this integral does not converge] https://mathematica.stackexchange.com/questions/144965/mathematica-erroneously-says-this-integral-does-not-converge
Mathematica (as of v. 11.1.0) does not recognize that this special case of Frullani’s integral converges:
Integrate[(ArcTan[a*x] - ArcTan[b*x])/x, {x, 0, Infinity}] (* Integrate::idiv: Integral of ...
- asked by Pillsy (10 votes), answered by Michael E2 (16 votes)
================================== Greatest hits from previous weeks: ==================================
[Generating a Sierpinski carpet] https://mathematica.stackexchange.com/questions/22052/generating-a-sierpinski-carpet
I am trying to draw a Sierpinski_carpet. I have code that works, but I think there is a more elegant way to do than my way. Maybe I couls use Tuples or Permutations or some similar function to ...
- asked by chyaong (46 votes), answered by Mr.Wizard (75 votes)
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[Alternatives to procedural loops and iterating over lists in Mathematica] https://mathematica.stackexchange.com/questions/7924/alternatives-to-procedural-loops-and-iterating-over-lists-in-mathematica
While there are some cases where a For loop might be reasonable, it’s a general mantra one I subscribe to myself that "if you are using a For loop in Mathematica, you are probably doing it wrong". ...
- asked by Mr.Wizard (154 votes), answered by Mr.Wizard (104 votes)
================================== Can you answer these? ==================================
[How to get parent key in Query on Association/Dataset?] https://mathematica.stackexchange.com/questions/144995/how-to-get-parent-key-in-query-on-association-dataset
Is there a general and terse method to obtain the parent key of the current "position" in a Query of an Association/Dataset?
Say I have the following Association.
assoc = <|"A" -> ...
- asked by Edmund (3 votes)
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[Can anyone help me decipher these few lines? Also, converting this code for a 2x2 matrix input to a 3x3 matrix input?] https://mathematica.stackexchange.com/questions/145049/can-anyone-help-me-decipher-these-few-lines-also-converting-this-code-for-a-2x
Here’s the code. I’m completely new to Mathematica so bear with me.
clear[ug]; ug[{{a11_, a12_}, {a21_, a22_}}] := Module[{A, f, b1, b2, y1, y2, U, P1, P2, UG}, A = {{a11, a12}, {a21, a22}}; ...
- asked by Pacotacobell (2 votes)
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[Bifurcation package like AUTO?] https://mathematica.stackexchange.com/questions/144795/bifurcation-package-like-auto
I was wondering if there is any available continuation and bifurcation analysis package for Mathematica. I’m looking for something like AUTO. I’ve seen there is already a Matlab version of the ...
- asked by Mirko Aveta (3 votes)
================================== Top new questions this week: ==================================
[Fast spherical polygon] https://mathematica.stackexchange.com/questions/144167/fast-spherical-polygon
Cross posted on Wolfram Community
Question
Given a list of points on a sphere and the sphere’s radius, I’d like to plot a spherical polygon with those points as vertices.
And this needs to be fast, ...
- asked by Kuba (20 votes), answered by halirutan (7 votes)
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[How to uncompress strings safely (without any evaluation)?] https://mathematica.stackexchange.com/questions/144171/how-to-uncompress-strings-safely-without-any-evaluation
Compressed strings are often used to exchange Mathematica expressions on the Internet. It is, however, not easy to see what such expression will do after decompression. Resulting code can perform ...
- asked by Shadowray (15 votes), answered by Itai Seggev (11 votes)
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[Sharing data via the cloud] https://mathematica.stackexchange.com/questions/144130/sharing-data-via-the-cloud
I’ve got some stuff that I want to be able distribute to my totally real friends, but I don’t want to have to email them every time I change something.
How can I set up sharing via the cloud?
- asked by MB1965 (13 votes), answered by MB1965 (13 votes)
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[C++ interface to large project] https://mathematica.stackexchange.com/questions/144047/c-interface-to-large-project
We are developing a quite large mathematical software in C++ and would like to have a Mathematica interface. We have our own C++ library and our idea would be, to write a Mathematica wrapper class and ...
- asked by Richard (12 votes), answered by Szabolcs (12 votes)
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[Why doesn’t FullSimplify return -x working on Abs[x] and x<0?] https://mathematica.stackexchange.com/questions/144310/why-doesnt-fullsimplify-return-x-working-on-absx-and-x0
I am using Mathematica 11.1, and I stumbled upon this strange response using the Abs function.
FullSimplify[Abs[x],x<0] (* Abs[x] *) while, for example FullSimplify[Abs[x],x>0] (* x *)
as ...
- asked by mickep (10 votes), answered by Simon Woods (13 votes)
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[ParallelMap vs Map performance comparsion] https://mathematica.stackexchange.com/questions/144056/parallelmap-vs-map-performance-comparsion
The ParallelMap claims doing map faster than the normal Map, and I checked the demo does as the document describing
but, I try my testing, it seems not exactly while ParallelMap excuting with 8 ...
- asked by Jerry (10 votes), answered by Szabolcs (10 votes)
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[How to plot a matrix with 3D style] https://mathematica.stackexchange.com/questions/144443/how-to-plot-a-matrix-with-3d-style
I have a list like
SeedRandom[1] MatrixForm[list = RandomInteger[5, {5, 5}]] We can plot it with MatrixPlot directly with 2D style MatrixPlot[list]
I hope to plot it with 3D style.This is ...
- asked by yode (9 votes), answered by kglr (2 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?] https://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (463 votes), answered by faysou (410 votes)
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[How can I plot the direction field for a differential equation?] https://mathematica.stackexchange.com/questions/8841/how-can-i-plot-the-direction-field-for-a-differential-equation
I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...
- asked by Matt Groff (20 votes), answered by Peter Breitfeld (16 votes)
================================== Can you answer these? ==================================
[Quality of RegionIntersection[]: How to control?] https://mathematica.stackexchange.com/questions/144270/quality-of-regionintersection-how-to-control
This code produces a crude intersection.
a = {-1/2, -1/2, -1/2}; b = {1/2, 1/2, 1/2}; R = RegionIntersection[Ball[a, 1], Ball[b, 1]]; Region[R]
How can I control the quality so that the ...
- asked by Joseph O’Rourke (4 votes)
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[Why ReadList ignores NullRecords for Number?] https://mathematica.stackexchange.com/questions/144149/why-readlist-ignores-nullrecords-for-number
When thinking on this recent question the immediately obvious solution which came to my mind was to use ReadList with options RecordLists -> True and NullRecords -> True for reading objects of ...
- asked by Alexey Popkov (5 votes)
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[Why does the domain of an interpolating function not match the corresponding ParametricNDSolve solution range?] https://mathematica.stackexchange.com/questions/144355/why-does-the-domain-of-an-interpolating-function-not-match-the-corresponding-par
Question
I had believed - and mostly observed - that when I use ParametricNDSolve the obtained ParametricFunctions given as the solution to some ODE or DAE will be translated into ...
- asked by gwr (3 votes)
================================== Top new questions this week: ==================================
[Crack CAPTCHA using deep learning] https://mathematica.stackexchange.com/questions/143691/crack-captcha-using-deep-learning
Deep convolutional neural networks are very good at computer vision related tasks. Optical Character Recognition (OCR) is one important branch of computer vision. In fact, the convolution neural ...
- asked by xslittlegrass (50 votes), answered by xslittlegrass (52 votes)
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[Changes to Series[...] in version 11.1] https://mathematica.stackexchange.com/questions/143414/changes-to-series-in-version-11-1
I have updated to Mathematica 11.1 and I am shocked to see that the Series-function now works differently:
If I enter
Series[x^2+x^3, {x,0,0}] it will return x^2+O[x]^3
which is just weird. In ...
- asked by Matthias Koenig (16 votes), answered by QuantumDot (3 votes)
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[WLNet format incompatible between version 11.0 and 11.1] https://mathematica.stackexchange.com/questions/143699/wlnet-format-incompatible-between-version-11-0-and-11-1
It seems that there are some behavior changes of neural network layers from version 11.0 to 11.1 that leads to the incompatibility of WLNet format.
Consider this example:
Network exported in 11.0
...
- asked by xslittlegrass (13 votes), answered by Taliesin Beynon (7 votes)
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[DSolve solution depends on ordering of equation] https://mathematica.stackexchange.com/questions/143726/dsolve-solution-depends-on-ordering-of-equation
Bug introduced in 8.0 or earlier and persisting through 11.1.0 or later
I am trying to obtain the general solution, \(G(x_1,x_2,x_3,x_4)\) to the very easy system of PDEs:
- asked by Jeremy Upsal (12 votes), answered by Nasser (8 votes)
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[Why the Callout option makes plotting performance poor] https://mathematica.stackexchange.com/questions/143711/why-the-callout-option-makes-plotting-performance-poor
Bug introduced in 11.0 and fixed in 11.1
The Callout option is a new option for plotting, but the performance is very poor, see bellow testing case.
num = 1000; list = N@Sin@Range[num]; list2 = ...
- asked by Jerry (11 votes)
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[Neural machine translation model using deep learning] https://mathematica.stackexchange.com/questions/143609/neural-machine-translation-model-using-deep-learning
In Mathematica version 11.1, SequenceAttentionLayer is introduced to model attentions in the recurrent neural network. It has been shown that attention mechanism can greatly improve the quality of a ...
- asked by xslittlegrass (11 votes), answered by Sebastian (8 votes)
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[Backslide in NSolve in V11.1?] https://mathematica.stackexchange.com/questions/143824/backslide-in-nsolve-in-v11-1
In V11.1,
NSolve[BesselJ[0, x] == 0 && 0 < x < 20, x]
returns no solutions:
But in V11.0 (and earlier), it returns all solutions:
Is there anyway to get NSolve to solve this ...
- asked by Michael E2 (10 votes), answered by Nasser (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to perform a multi-peak fitting?] https://mathematica.stackexchange.com/questions/26336/how-to-perform-a-multi-peak-fitting
I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data peak1 + peak2 + peak3).
The ...
- asked by Everett You (43 votes), answered by Silvia (45 votes)
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[How to make an inkblot?] https://mathematica.stackexchange.com/questions/3345/how-to-make-an-inkblot
How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):
RandomBlot[num_, opts___] := ...
- asked by István Zachar (84 votes), answered by Sjoerd C. de Vries (47 votes)
================================== Can you answer these? ==================================
[How to create an APIFunction that takes a list with constraints on the list elements?] https://mathematica.stackexchange.com/questions/143709/how-to-create-an-apifunction-that-takes-a-list-with-constraints-on-the-list-elem
This APIFunction takes a list as an argument:
func = APIFunction[{"x" -> DelimitedSequence["Integer", ","]}, #x^3 &] func["x" -> Range[4]]
What I’d like to be able to do is place a ...
- asked by Mike Honeychurch (4 votes)
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[How to setup FrameTicks for TradingChart] https://mathematica.stackexchange.com/questions/143705/how-to-setup-frameticks-for-tradingchart
I’m trying to setup FrameTicks for TradingChart, but it dosn’t work.
(*take data*) data = FinancialData["NASDAQ:AAPL", "OHLCV", {{2017, 1, 1}, {2017, 4, 16}}]; (*def. of ticks*) maxh = ...
- asked by Jerry (3 votes)
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[What are the software requirements to train neural networks on GPU?] https://mathematica.stackexchange.com/questions/143795/what-are-the-software-requirements-to-train-neural-networks-on-gpu
It seems that GPU training in Mathematica has some additional requirements on the software. For example, when I run this example on a Linux system, I get the following errors
trainingData = ...
- asked by xslittlegrass (8 votes)
================================== Top new questions this week: ==================================
[L-System in Mathematica] http://mathematica.stackexchange.com/questions/143214/l-system-in-mathematica
Here is some Maple code for drawing an L-System:
with(Fractals:-LSystem) cons := ["A" = "draw:1", "+" = "turn:-90", "B" = "turn:90"] state, rules := "A", ["A" = "AB+BA+B", "B" = "B+AAB"] ...
- asked by vito (21 votes), answered by Szabolcs (21 votes)
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[What’s purpose of the new function BinarySerialize?] http://mathematica.stackexchange.com/questions/141885/whats-purpose-of-the-new-function-binaryserialize
11.1 introduced a new function BinarySerialize, but I don’t know what it can do better than the traditional method.Its behavior is very similar to Compress,though I cannot find any advantage of it.It ...
- asked by yode (17 votes), answered by Shadowray (14 votes)
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[Why does SetPrecision not apply to 0?] http://mathematica.stackexchange.com/questions/143296/why-does-setprecision-not-apply-to-0
Is there a rationale why SetPrecision works on integers except for 0?
SetPrecision[1,5] 1.0000 SetPrecision[0,5] 0
- asked by alancalvitti (11 votes), answered by Shadowray (17 votes)
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[How to use Mathematica to train a network Using out of core classification?] http://mathematica.stackexchange.com/questions/142135/how-to-use-mathematica-to-train-a-network-using-out-of-core-classification
I see there is doc about how to train a network Using out of core image classification and this question.But the object is only image.
I want to use a binary file as data,for example,this.
data = ...
- asked by partida (10 votes), answered by xslittlegrass (9 votes)
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[Combining pure functions] http://mathematica.stackexchange.com/questions/142072/combining-pure-functions
Is there an easy way to combine pure functions into a single pure function? For example, say I have
f = #1^2 &; g = #1 - 2 &;
and I want to define a new pure function h that is the ...
- asked by tparker (10 votes), answered by Kuba (5 votes)
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[Question about changes in Documentation Center from version 10 to 11] http://mathematica.stackexchange.com/questions/143335/question-about-changes-in-documentation-center-from-version-10-to-11
The package Exploring Abstract Algebra with Mathematica works fine in Mathematica 10.4.
After installing it in the $UserBaseDirectory it neatly shows up under Add-Ons and Packages in the ...
- asked by nilo de roock (9 votes), answered by Szabolcs (8 votes)
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[How can I install packages distributed as .paclet files?] http://mathematica.stackexchange.com/questions/141887/how-can-i-install-packages-distributed-as-paclet-files
I downloaded a Mathematica package. It came as a file with the .paclet extension. How can I install or uninstall it?
- asked by Szabolcs (9 votes), answered by Szabolcs (8 votes)
================================== Greatest hits from previous weeks: ==================================
[Exporting graphics to PDF - huge file] http://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[], r Sin[], r^2}, {r, 0, ...
- asked by Matthew Leingang (90 votes), answered by Heike (77 votes)
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[Unit Discovery: Is this some sort of a sick joke?] http://mathematica.stackexchange.com/questions/124745/unit-discovery-is-this-some-sort-of-a-sick-joke
Alright, let’s have some fun here. I am essentially following the documentation by Wolfram, just looking at different quantities.
N[UnitConvert[Quantity["earth's gravity"]]] 9.80665m/(s)^2 Hmm, ...
- asked by Pirx (31 votes), answered by user31159 (30 votes)
================================== Can you answer these? ==================================
[How to get consistent/predictable results from ‘Alignment‘ specs within a ‘Grid‘ environment?] http://mathematica.stackexchange.com/questions/142047/how-to-get-consistent-predictable-results-from-alignment-specs-within-a-grid
IME, the results of Alignment specifications within a Grid environment are completely unpredictable.
I give several examples below illustrating this unpredictability.
My questions are:
Is there a ...
- asked by kjo (4 votes)
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[Why Integrate does not work in the first call?] http://mathematica.stackexchange.com/questions/143199/why-integrate-does-not-work-in-the-first-call
Consider an example (calculated in Mathematica 11.0.1.0):
In[1]:= Integrate[(Sin[(\[Pi] xc)/(2 Lc)] Sin[(m \[Pi] ...
- asked by Shinrei (3 votes)
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[Geo data load issues: Texas is missing from GeoRegionValuePlot in v11, but only when mapping US states] http://mathematica.stackexchange.com/questions/142079/geo-data-load-issues-texas-is-missing-from-georegionvalueplot-in-v11-but-only
UPDATE: this is not a global Mathematica issue, but a data load issue on a local machine. Does anyone know how to clear Geo cache and reload the data? I’ve also noticed on this machine that ...
- asked by Gregory Klopper (3 votes)
================================== Top new questions this week: ==================================
[Object detection and localization using neural network] http://mathematica.stackexchange.com/questions/141598/object-detection-and-localization-using-neural-network
Four important computer vision tasks are classification, localization, object detection and instance segmentation (image taken from cs224d course):
These four tasks are all built on top of the deep ...
- asked by xslittlegrass (30 votes), answered by xslittlegrass (33 votes)
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[Ball Bouncing on Hilly Terrain] http://mathematica.stackexchange.com/questions/141209/ball-bouncing-on-hilly-terrain
There is a maple code for the bouncing ball on the given curve.
I tried to make this animation by using Mathematica
Why does the following code not work?
surf := Sin[x] + (0.2 Cos[4 x + Sin[4 ...
- asked by vito (19 votes), answered by Stitch (15 votes)
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[Dataset is 20X slow when adding column heads] http://mathematica.stackexchange.com/questions/141223/dataset-is-20x-slow-when-adding-column-heads
I’m trying to use Dataset to explore some large data. I notice that the performance decrease more than 20X by adding heads to the columns. Here is an example:
We generate some data with integers
...
- asked by xslittlegrass (14 votes), answered by Mr.Wizard (3 votes)
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[Benchmarking: unexplained switching between high and low performance] http://mathematica.stackexchange.com/questions/141350/benchmarking-unexplained-switching-between-high-and-low-performance
tl;dr I am trying to accurately benchmark some vectorized operations, and compare them between systems. But benchmarking is hard to do well, and I am getting inconsistent results: performance is ...
- asked by Szabolcs (13 votes)
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[How to visualize attention?] http://mathematica.stackexchange.com/questions/141542/how-to-visualize-attention
In the articles about sequence attention we can see images like this:
Here we see that while translating from French to English, the network attends sequentially to each input state, but sometimes ...
- asked by Alexey Golyshev (12 votes), answered by xslittlegrass (4 votes)
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[Can one create a custom front-end for Mathematica?] http://mathematica.stackexchange.com/questions/141581/can-one-create-a-custom-front-end-for-mathematica
I’d like to create my custom front-end for Mathematica. I know there’s a console interface (launched as math), which mostly works great, but it can’t really provide functionality of e.g. interactive ...
- asked by Ruslan (9 votes)
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[How to clear Integrate internal memory?] http://mathematica.stackexchange.com/questions/141324/how-to-clear-integrate-internal-memory
I noticed that when I call Integrate for the first time, on an integral that I know will take longer than the time limit I give it, it will abort for the first time, as expected when wrapped by ...
- asked by Nasser (9 votes), answered by J. M. (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating legends for plots with multiple lines?] http://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines
So I have a graph with multiple lists, for e.g.
data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have no way to generate a legend ...
- asked by Eiyrioü von Kauyf (60 votes), answered by Jens (89 votes)
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[Labeling individual curves in Mathematica] http://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (49 votes), answered by Artes (39 votes)
================================== Can you answer these? ==================================
[GraphicsComplex dynamic colors] http://mathematica.stackexchange.com/questions/141489/graphicscomplex-dynamic-colors
I have a fairly large GraphicsComplex (surface mesh with more than several thousand vertices) and I want to visualize a scalar function that is defined on the vertices. I map the function to vertex ...
- asked by Beginner (6 votes)
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[how to efficiently generate all directed graphs with 6 vertices] http://mathematica.stackexchange.com/questions/141681/how-to-efficiently-generate-all-directed-graphs-with-6-vertices
I am attempting to generate all non-isomorphic directed graphs with 6 vertices using command ListGraphs[6, Directed].But it does not work efficiently and takes a month producing nothing.
Can anyone ...
- asked by Mike (6 votes)
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[Bug in Limit in version 11.1.0] http://mathematica.stackexchange.com/questions/141233/bug-in-limit-in-version-11-1-0
Bug introduced in version 11.1.0
The infinite limit
Assuming[a>0&&b>0, Limit[((1+a)*b*x)/Sqrt[1+(1+a)*b*x*((1+a)*b*x+Sqrt[1+(1+a)^2*b^2*x^2])], x->Infinity]]
gives the ...
- asked by Roman (5 votes)
================================== Top new questions this week: ==================================
================================== Top new questions this week: ==================================
[Faster derangements?] http://mathematica.stackexchange.com/questions/140794/faster-derangements
I wonder what is the fastest method to generate derangements?
Both the Combinatorica function and Martin Ender’s answer to Permutations of lists of fixed even numbers are based on filtering the ...
- asked by Mr.Wizard (22 votes), answered by jkuczm (21 votes)
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[Why Except is so slow as compared to equivalent RegularExpression?] http://mathematica.stackexchange.com/questions/140752/why-except-is-so-slow-as-compared-to-equivalent-regularexpression
When comparing performance of the solutions suggested for this question I discovered that StringExpression involving Except is two orders of magnitude slower for large strings as compared to ...
- asked by Alexey Popkov (18 votes), answered by Alexey Popkov (20 votes)
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[FrameTicks setting for "tick marks on all sides, but labels only on right and top"] http://mathematica.stackexchange.com/questions/140966/frameticks-setting-for-tick-marks-on-all-sides-but-labels-only-on-right-and-to
Short version: Is there a value for the FrameTicks option that retains the default tick marks on all sides, and puts tick labels only on the right and top sides?
I can imagine all manner of ...
- asked by kjo (15 votes), answered by Mr.Wizard (7 votes)
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[Quickly importing several thousands of jpg files?] http://mathematica.stackexchange.com/questions/140974/quickly-importing-several-thousands-of-jpg-files
I have several thousands of small .jpg files (30kb each) which I need to import into Mathematica. (I plan to use ImageDistance to investigate their differences.) I tried several ways to import these ...
- asked by Kagaratsch (14 votes), answered by Szabolcs (13 votes)
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[Select seems unusually slow] http://mathematica.stackexchange.com/questions/140861/select-seems-unusually-slow
I haven’t been doing nearly as much Mathematica as I really should for the past few months, and in order to get my head back in the game I’ve been using it to run roughshod over easy Project Euler ...
- asked by Pillsy (13 votes), answered by Bob Hanlon (10 votes)
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[Permutations of nested parentheses (Dyck words)] http://mathematica.stackexchange.com/questions/141127/permutations-of-nested-parentheses-dyck-words
How would I construct a function that outputs Dyck Words?
e.g. - there are 14 words in \(\mathcal {D}_{8}\):
`[[[[]]]], [[[][]]], [[[]][]], [[][[]]], [[[]]][], [[][][]], [][[[]]], [[][]][], [[]][[]], ...
- asked by martin (11 votes), answered by Mr.Wizard (13 votes)
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[Bug: Library functions from older versions of Mathematica may crash in Mathematica 11.1 and conversely] http://mathematica.stackexchange.com/questions/140758/bug-library-functions-from-older-versions-of-mathematica-may-crash-in-mathemati
The following is a confirmed bug [CASE:3846875] that turned up in the prerelease 11.1.0 and is not solved in the official release.
This is a small example. Execute the following commands in ...
- asked by Fred Simons (11 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make a Spherical Cow?] http://mathematica.stackexchange.com/questions/125043/how-to-make-a-spherical-cow
Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...
- asked by Sumit (60 votes), answered by andre (69 votes)
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[How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc] http://mathematica.stackexchange.com/questions/66273/how-to-tell-mathematica-that-certain-variables-are-real-imaginary-integer-value
I’m trying to expedite some quantum mechanical calculations (expectation values etc.) by running them through Mathematica. When I say, for example,
u[x_] := Sqrt[2/L] * Sin[Pi * n * x / L]
and then ...
- asked by Matthew Brunetti (13 votes), answered by SquareOne (10 votes)
================================== Can you answer these? ==================================
[Why does LatticeReduce require integral or at least rational inputs?] http://mathematica.stackexchange.com/questions/141002/why-does-latticereduce-require-integral-or-at-least-rational-inputs
The function LatticeReduce in Mathematica implements the LLL algorithm. It requires the lattice basis to be described as integral or at least rational numbers.
Why so?
The LLL algorithm itself is ...
- asked by wdlang (3 votes)
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[Textual progress in console?] http://mathematica.stackexchange.com/questions/140675/textual-progress-in-console
Is there any way to get a textual progress bar (e.g. like the progressbar module in a python repl) when working in console mode?
Anything would be better than this:
- asked by user5601 (6 votes)
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[How to trigger an "ErrorBox behavior"?] http://mathematica.stackexchange.com/questions/140979/how-to-trigger-an-errorbox-behavior
Here’s an example of what I mean by an "ErrorBox behavior". In the front end, if one evaluates the expression
Graphics[Circle[], ImageSize -> Tiny, PlotRange -> {All}]
(which includes the ...
- asked by kjo (7 votes)
================================== Top new questions this week: ==================================
[V11.1: Effective methods to use paid functions economically] http://mathematica.stackexchange.com/questions/140261/v11-1-effective-methods-to-use-paid-functions-economically
In the newly released version 11.1, Mathematica introduces three new functions: WebSearch, WebImageSearch and TextTranslation that requires Service Credits. While I haven’t found much information ...
- asked by happy fish (30 votes), answered by Wjx (14 votes)
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[How do I disable the stack tracing feature in Mathematica 11?] http://mathematica.stackexchange.com/questions/140285/how-do-i-disable-the-stack-tracing-feature-in-mathematica-11
Bug was introduced in 11.0 and persisting through 11.1
It looks like the Mathematica 11 stack tracing feature (see red ellipsis in front of any warning message) prevents the garbage collector from ...
- asked by Shadowray (28 votes), answered by user6014 (23 votes)
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[Generative Adversarial Network] http://mathematica.stackexchange.com/questions/140294/generative-adversarial-network
Generative adversarial networks (GAN) is regarded as one of "the most interesting idea in the last ten years in machine learning" by Yann LeCun. It can be used to generate photo-realistic images that ...
- asked by xslittlegrass (17 votes), answered by Taliesin Beynon (8 votes)
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[Modeling the spread of an infection in networked computers] http://mathematica.stackexchange.com/questions/140099/modeling-the-spread-of-an-infection-in-networked-computers
I would like to show the iterative stages of infection for problem 2 in this link.
In case the link dies, I have copied the text for the problem below:
One hundred computers are connected in a ...
- asked by martin (14 votes), answered by Martin Ender (24 votes)
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[how to remove the little Œ that shows up in frontend when typing?] http://mathematica.stackexchange.com/questions/140583/how-to-remove-the-little-x-that-shows-up-in-frontend-when-typing
Version 11.1 now shows a little grayed out x (a multiplication sign) when one is editing something, to warn them that the expression will be interpreted as the multiplication of what precedes and ...
- asked by Nasser (12 votes), answered by Nasser (18 votes)
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[Delete redundant x,y pairs] http://mathematica.stackexchange.com/questions/140571/delete-redundant-x-y-pairs
Working through the problems from Hazrat’s Mathematica book and there’s a simple exercise to find all the square numbers where \(n^2+m^2=h^2\) yields \(h\) as an integer (I think they’re also called ...
- asked by Joe (10 votes), answered by kglr (13 votes)
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[Getting Compile to work with Visual Studio 2017 Community Edition] http://mathematica.stackexchange.com/questions/140071/getting-compile-to-work-with-visual-studio-2017-community-edition
The new Visual Studio is out since a week and I tried to get it to work with Mathematica (v 11.0). However the usual tricks for working with a new VS version fail here.
Related seems to be the ...
- asked by Sjoerd C. de Vries (10 votes)
================================== Greatest hits from previous weeks: ==================================
[1 Plot, 2 Scale/Axis] http://mathematica.stackexchange.com/questions/627/1-plot-2-scale-axis
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
- asked by 500 (114 votes), answered by ArgentoSapiens (110 votes)
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[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (34 votes), answered by Artes (25 votes)
================================== Can you answer these? ==================================
[Explaining error when using Part inside Module in Dataset] http://mathematica.stackexchange.com/questions/140541/explaining-error-when-using-part-inside-module-in-dataset
I have a vague recollection of seen an explanation for this, but I can not find it, so it may be a false memory. Will delete if duplicated.
Let ds be a simple Dataset
ds = Dataset@Table[ ...
- asked by rhermans (4 votes)
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[Performance-driven approach to using Big Data without killing the hard-drive] http://mathematica.stackexchange.com/questions/140114/performance-driven-approach-to-using-big-data-without-killing-the-hard-drive
Situation
A calculation has to be done in which the amount of data is too much to fit into memory. Fortunately, only a part of the overall data set has to be known at a time. The preprocessing is ...
- asked by pbx (7 votes)
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[Bug with PlotLegends->Placed in GraphicsRow] http://mathematica.stackexchange.com/questions/140539/bug-with-plotlegends-placed-in-graphicsrow
Bug introduced in 11.0 and persisting through 11.1
The FrontEnd of Mathematica 11.1.0 on my Windows 7 box runs permanently at 100% CPU when I execute the following command:
...
- asked by RonH (3 votes)
================================== Top new questions this week: ==================================
[How to implement a discrete data representation?] http://mathematica.stackexchange.com/questions/139818/how-to-implement-a-discrete-data-representation
I’m currently working with large datasets of "discrete data". Each of these is a multiset of real numbers of the form \(kS + B\), where \(k\) is an integer, and \(S\) (the "scale") and \(B\) (the "bias") are ...
- asked by kjo (17 votes), answered by gwr (14 votes)
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[Mathematica incorrectly giving zero for partial derivative] http://mathematica.stackexchange.com/questions/139669/mathematica-incorrectly-giving-zero-for-partial-derivative
Bug introduced in 9.0.1 or earlier
Mathematica is incorrectly reporting that the partial derivative of a certain expression is zero.
I try to compute the following:
D[SymmetricPolynomial[3, {x1, ...
- asked by Izaak Meckler (17 votes), answered by march (6 votes)
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[Finding vampire numbers] http://mathematica.stackexchange.com/questions/139808/finding-vampire-numbers
How to find vampire numbers by using Mathematica?
A number \(v=xy\) with an even number \(n\) of digits formed by multiplying a pair of \(n/2\)-digit numbers (where the digits are taken from the ...
- asked by vito (13 votes), answered by wolfies (8 votes)
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[Why do subsequent evaluations seem to be stopped by a False Condition (/;)?] http://mathematica.stackexchange.com/questions/139461/why-do-subsequent-evaluations-seem-to-be-stopped-by-a-false-condition
Exploring another problem and this example of @halirutan, I came across an evaluation behavior I don’t understand.
When g[] below is evaluated the first time, ig[] is evaluated and a message printed; ...
- asked by Michael E2 (12 votes), answered by Carl Woll (13 votes)
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[Bug? Numerical calculation error with FullSimplify and arbitrary precision] http://mathematica.stackexchange.com/questions/139697/bug-numerical-calculation-error-with-fullsimplify-and-arbitrary-precision
Bug introduced after 5.2, fixed in 8.0, reintroduced in 9.0 and persisting through 11.0.1
Is this a bug?
If I do
FullSimplify[n E^(0``10 n)] then it returns n/2
what is obviously incorrect.
...
- asked by David Bevan (10 votes)
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[Is there a convention on which name to use for a throwaway variable? (Like underscore in Python)] http://mathematica.stackexchange.com/questions/139622/is-there-a-convention-on-which-name-to-use-for-a-throwaway-variable-like-under
I would prefer to write {_, foo} = LongFunctionName[arg1, arg2] instead of foo = LongFunctionName[arg1, arg2][[2]] or foo = Last @ LongFunctionName[arg1, arg2]. Using an actual name for the throwaway ...
- asked by ZeitPolizei (10 votes), answered by Mr.Wizard (5 votes)
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[Extract images from large avi movies (50-100 GB)] http://mathematica.stackexchange.com/questions/139819/extract-images-from-large-avi-movies-50-100-gb
I will get large RGB avi files (35 Hz, 1600*1200 pixels) of up to 100 GB size. All three channels contain the same grayscale image.
I want to extract each avi file into one channel png images.
To do ...
- asked by mrz (8 votes), answered by mrz (11 votes)
================================== Greatest hits from previous weeks: ==================================
[How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc] http://mathematica.stackexchange.com/questions/66273/how-to-tell-mathematica-that-certain-variables-are-real-imaginary-integer-value
I’m trying to expedite some quantum mechanical calculations by running them through Mathematica. Expectation values and stuff like that. When I say, for example,
u[x_] := Sqrt[2/L] * Sin[Pi * n * x / ...
- asked by Matthew Brunetti (11 votes), answered by SquareOne (9 votes)
—————————-
[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (460 votes), answered by faysou (404 votes)
================================== Can you answer these? ==================================
[Integrating rational functions of several variables over \(\mathbb {H}^4\)] http://mathematica.stackexchange.com/questions/139631/integrating-rational-functions-of-several-variables-over-mathbbh4
Let \(W\) be a rational function of \(8\) variables \(a,b,c,d,e,f,g,h\) from this file, e.g.:
W = (256*b*d*f*(a^5 + b^4*(c - 2*e) - a^4*(3*c + 2*e) - c*(c^2 + d^2)*(e^2 + f^2) + a^3*(2*b^2 + 3*c^2 + d^2 + ...
- asked by Ricardo Buring (4 votes)
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[Best Wolfram tool for interactive web-based calculator] http://mathematica.stackexchange.com/questions/139954/best-wolfram-tool-for-interactive-web-based-calculator
A colleague is considering re-implementing this online "Photon Propulsion Calculator" using a Mathematica-based product. I wanted to ask the community which product would be best.
WebMathematica
...
- asked by ConvexMartian (8 votes)
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[How to get rid of a built-in context from autocomplete?] http://mathematica.stackexchange.com/questions/139783/how-to-get-rid-of-a-built-in-context-from-autocomplete
I have noticed that when I type the name of built-in function Limit in Mathematica, the autocomplete suggests two variants at the top: the first one is the working one, and the second one is just ...
- asked by user372003 (4 votes)
================================== Top new questions this week: ==================================
[What are some common issues with fitting functions to data?] http://mathematica.stackexchange.com/questions/139038/what-are-some-common-issues-with-fitting-functions-to-data
Mathematica has numerous functions designed to, or capable of, fitting known functions, and finding unknown functions to match data sets. What are some common issues that come with finding those fits? ...
- asked by Feyre (20 votes), answered by Feyre (21 votes)
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[Notebook’s TaggingRules inherit too much] http://mathematica.stackexchange.com/questions/139017/notebooks-taggingrules-inherit-too-much
Bug introduced in V10.4 or earlier and persisting through 11.0.1
[CASE:3852725]
was created
[...] I have forwarded an incident report to our developers with the information you provided. ...
- asked by Kuba (14 votes), answered by Kuba (3 votes)
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[Is ExportString defective in V11?] http://mathematica.stackexchange.com/questions/138932/is-exportstring-defective-in-v11
Mathematica doesn’t do the best job of exporting figures with shading or transparency to vector graphics formats such as PDF.
A common trick employed here and elsewhere on the web to workaround this ...
- asked by Quantum_Oli (11 votes)
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[Commands to stop and continue evaluation without Debugger] http://mathematica.stackexchange.com/questions/139377/commands-to-stop-and-continue-evaluation-without-debugger
I would like to stop the evaluation somehwere at a specifiy line in a notebook. Then I could for example check the state of some variables.
After that I would like to continue the evaluation from the ...
- asked by lio (10 votes), answered by Szabolcs (9 votes)
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[How am I misusing EvenQ, or, how are EvenQ and (Mod[2,#]==0)&
differently evaluated?]
http://mathematica.stackexchange.com/questions/139281/how-am-i-misusing-evenq-or-how-are-evenq-and-mod2-0-differently-evalua
While working on a problem, I was using EvenQ in a RegionPlot. I came across this interesting case (simplified here for specificity). I expected to see a bunch of stripes, but got nothing:
...
- asked by Piquan (10 votes), answered by Mr.Wizard (9 votes)
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[Partition a list by count of a number] http://mathematica.stackexchange.com/questions/138905/partition-a-list-by-count-of-a-number
I want to take this list when the 2 appear 3 times
SeedRandom[1] list = RandomChoice[{.2, .5, .3} -> {1, 2, 3}, 20] {3,1,3,1,2,1,2,2,2,3,2,3,2,2,3,3,3,2,2,2} Hope to get {{3, 1, 3, 1, 2, 1, ...
- asked by yode (10 votes), answered by Mr.Wizard (5 votes)
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[Why SciDraw can not handle the StreamPlot?] http://mathematica.stackexchange.com/questions/138926/why-scidraw-can-not-handle-the-streamplot
I find that the package SciDraw is suitable for preparing the figure in the thesis. When I use it to plot the line, it works well. For example
<<SciDraw` ...
- asked by Ice0cean (10 votes), answered by Szabolcs (11 votes)
================================== Greatest hits from previous weeks: ==================================
[How to express trigonometric equation in terms of of given trigonometric function?] http://mathematica.stackexchange.com/questions/434/how-to-express-trigonometric-equation-in-terms-of-of-given-trigonometric-functio
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
Sin[x]^2+Cos[x]^2==1 Sin[x]/Cos[x]==Tan[x] ...
- asked by Prashant Bhate (25 votes), answered by Simon (32 votes)
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[Calculate the 2D Fourier transform of an Image] http://mathematica.stackexchange.com/questions/29203/calculate-the-2d-fourier-transform-of-an-image
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase spectrum, as well as reconstruct the ...
- asked by user8727 (5 votes), answered by Nasser (27 votes)
================================== Can you answer these? ==================================
[Two-Point correlation function of Ising data is not giving expected results] http://mathematica.stackexchange.com/questions/139016/two-point-correlation-function-of-ising-data-is-not-giving-expected-results
Due to the nature of my problem, and readers perhaps not having a physics background, I need to give some context to my problem which is intrinsic to it. The problem however is not a physics one, but ...
- asked by Luca Pontiggia (3 votes)
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[Evaluating an expectation expressed by a difficult expression] http://mathematica.stackexchange.com/questions/138917/evaluating-an-expectation-expressed-by-a-difficult-expression
Background
I have a 2-dimensional space. The receiver is at the center. The locations of transmitters are given by the PPP \(\Phi \) with density \(\lambda \). The serving transmitter is the one that is ...
- asked by George Harnandez (3 votes)
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[How to control indentation of a cell relative to it’s parent?] http://mathematica.stackexchange.com/questions/138971/how-to-control-indentation-of-a-cell-relative-to-its-parent
Is there a stylesheet property that can be set to control the extra level of indentation of a cell in its group (I don’t want to specify absolute CellMargins)?
Carl suggests in the comments to use ...
- asked by user5601 (3 votes)
================================== Top new questions this week: ==================================
[Parallelize Map and ParallelMap] http://mathematica.stackexchange.com/questions/138476/parallelize-map-and-parallelmap
Bug introduced in 8.0 and persisting through 11.0.1 or later
It is stated in the documentation that
Parallelize[Map[f, expr]] is equivalent to ParallelMap[f, expr].
But what about these ...
- asked by Mher (29 votes), answered by Szabolcs (23 votes)
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[Can we intelligently control evaluation in Thread?] http://mathematica.stackexchange.com/questions/138661/can-we-intelligently-control-evaluation-in-thread
This is a bid at creating a canonical Q&A.
Many questions have been asked that come down to the fact that Thread evaluates its first argument before threading is attempted. In a few minutes I ...
- asked by Mr.Wizard (27 votes), answered by Mr.Wizard (21 votes)
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[Learn Mathematica (Wolfram) Language in one day] http://mathematica.stackexchange.com/questions/138366/learn-mathematica-wolfram-language-in-one-day
Currently I am trying to learn Python. Searching for relevant material I came across
X in Y minutes
and books with titles such as Learn Python in one day, in 24 hours, etc.
Similar material exists ...
- asked by dimitris (23 votes), answered by masterxilo (5 votes)
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[Puzzle 20 People to consume 20 units of food under constraints] http://mathematica.stackexchange.com/questions/138637/puzzle-20-people-to-consume-20-units-of-food-under-constraints
I am learning Mathematica because I love it. I also love solving puzzles so I think it would be a nice way to learn Mathematica through puzzles. This is first puzzle in series I intend to solve.
So ...
- asked by Jawad_Mansoor (14 votes), answered by Mr.Wizard (18 votes)
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[Compute the curvature of a bent stack of paper] http://mathematica.stackexchange.com/questions/138583/compute-the-curvature-of-a-bent-stack-of-paper
My goal is to link the curvature of a bent stack of paper in a wind tunnel to its bending modulus \(B\), knowing all the other physical properties. To this end, I would like to reproduce the numerical ...
- asked by yketa (12 votes), answered by xzczd (8 votes)
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[WordOrientation does not work in v11?] http://mathematica.stackexchange.com/questions/138811/wordorientation-does-not-work-in-v11
Bug introduced in 11.0.1
It seems that WordOrientation does not work in v11. The sample code
input = ExampleData[{"Text", "AliceInWonderland"}]; WordCloud[input, WordOrientation -> "Random"]
...
- asked by Lem.ma (11 votes)
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[Code request: Make "copy formatted code" bulletproof] http://mathematica.stackexchange.com/questions/138436/code-request-make-copy-formatted-code-bulletproof
With the GeneralUtilities‘PrintDefinitions functions comes a usable code formatting engine. On this site, most of the time we share code. I believe it would be awesome to have a robust button that ...
- asked by halirutan (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Why round to even integers?] http://mathematica.stackexchange.com/questions/2116/why-round-to-even-integers
According to the Mathematica help:
Round rounds numbers of the form x.5 toward the nearest even integer.
For example:
Round[{0.5, 1.5, 2.5, 3.5, 4.5}] gives {0, 2, 2, 4, 4}
What’s the ...
- asked by wxffles (61 votes), answered by Per Alexandersson (37 votes)
—————————-
[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (33 votes), answered by Artes (24 votes)
================================== Can you answer these? ==================================
[Plotting a 2D slice of a 3D function] http://mathematica.stackexchange.com/questions/138808/plotting-a-2d-slice-of-a-3d-function
I'd like to plot (Sqrt[x] + Sqrt[y] + Sqrt[z])^2 in a slice defined by x+y+z=1
I figured out similar problem 5 years ago, but it was a bit involved, ie, needing 10 lines of Mathematica code. Is there ...
- asked by Yaroslav Bulatov (2 votes)
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[Export of Plot3D function completely different from the render within Mathematica] http://mathematica.stackexchange.com/questions/138412/export-of-plot3d-function-completely-different-from-the-render-within-mathematic
I am plotting a simple function:
Plot3D[-RandomReal[{0, 10}] Cos[x/3] Cos[y/3], {x, -, }, {y, -, }, Axes -> False, Boxed -> False, BoundaryStyle -> None, Mesh -> None]
...
- asked by waffl (1 vote)
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[CreateExecutable returns $Failed] http://mathematica.stackexchange.com/questions/138328/createexecutable-returns-failed
My platform is win10 64b, Mathematica 11 and Visual Studio 2015. When I apply CreateExecutable, it always returns $Failed. The configuration is right. Please what is the problem? Thank you.
...
- asked by tu312 (1 vote)
================================== Top new questions this week: ==================================
[How can I adaptively simplify a curved shape?] http://mathematica.stackexchange.com/questions/137937/how-can-i-adaptively-simplify-a-curved-shape
For the purposes of creating a publication-quality plot marker I wish to convert a font glyph into a simplified Polygon where points are taken adaptively according to curvature of the boundary. ...
- asked by Alexey Popkov (22 votes), answered by Szabolcs (29 votes)
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[Can Mathematica be used to make anamorphic distortions like these?] http://mathematica.stackexchange.com/questions/137853/can-mathematica-be-used-to-make-anamorphic-distortions-like-these
We have all see these sidewalk and street images that appear to be 3D based on the viewers perspective, but then wildly distort when viewed from a different perspective.
Seems to me anamorphic ...
- asked by R Hall (12 votes), answered by Simon Woods (10 votes)
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[How to implement lane-change rules for Nagel Schreckenberg model] http://mathematica.stackexchange.com/questions/138138/how-to-implement-lane-change-rules-for-nagel-schreckenberg-model
I am trying to extend the Nagel-Schreckenberg model for traffic flow to include two lanes of traffic.
I have a function that generates information about a random initial road configuration. A road ...
- asked by jlrawden (11 votes), answered by Ali Hashmi (5 votes)
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[How to make a custom NN layer in Mathematica?] http://mathematica.stackexchange.com/questions/138230/how-to-make-a-custom-nn-layer-in-mathematica
Is there a way to create our own custom layers for Neural Networks in Mathematica ? I suspect it should be possible, any pointers or directions on how to go about it?
I am interested in ...
- asked by Andy Stow Away (9 votes)
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[How to build private function with built-in function’s option] http://mathematica.stackexchange.com/questions/138126/how-to-build-private-function-with-built-in-functions-option
Since this code work well:
Needs["GeneralUtilities`"] GeneralUtilities`BenchmarkPlot[{SortBy[#, Identity] &, Sort}, Range, "IncludeFits" -> True, TimeConstraint -> 8]
I want to set ...
- asked by yode (9 votes), answered by Mr.Wizard (11 votes)
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[Doing combinations of sub-sublists] http://mathematica.stackexchange.com/questions/138178/doing-combinations-of-sub-sublists
To create a list of all the possible combinations of a sublist. I have a list, somewhat resembling the following format:
{{{a1, a2}, {b1}}, {{a1, a2}, {c1, c2}}, {{a1, a2}, {c1, c2}, {d1, d2}}}
...
- asked by Andrew Johnson (8 votes), answered by halirutan (11 votes)
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[Warning: FrontEnd crash with ‘Graphics@InfiniteLine‘ for unknown symbolic coordinates] http://mathematica.stackexchange.com/questions/137847/warning-frontend-crash-with-graphicsinfiniteline-for-unknown-symbolic-coordi
Bug introduced in 10.0 and persisting through 11.0.1 InfiniteLine is new in 10.0.
[CASE:3840702] From your description, I gather you are noticing an unexpected crash while trying to evaluate ...
- asked by masterxilo (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to add a vertical line to a plot] http://mathematica.stackexchange.com/questions/3561/how-to-add-a-vertical-line-to-a-plot
In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?
f[x_] := (x^2 z)/((x^2 - y^2)^2 + 4 q^2 x^2) /. {y -> /15, z -> 1, q -> ...
- asked by sjdh (33 votes), answered by Ajasja (49 votes)
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[Can Mathematica do symbolic linear algebra?] http://mathematica.stackexchange.com/questions/3242/can-mathematica-do-symbolic-linear-algebra
For instance, is there some way I can say "let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices,
Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ...
- asked by nikie (42 votes), answered by helen (21 votes)
================================== Can you answer these? ==================================
[Calculate PDF of difference of Max and Min for Gaussian random variables] http://mathematica.stackexchange.com/questions/138027/calculate-pdf-of-difference-of-max-and-min-for-gaussian-random-variables
Although this should be a standard question I didn’t find it in SE, and it was a nice exercise in Mathematica.
Let \(x\) and \(y\) be two independent Gaussian random variables with distribution \(N(0,1)\). ...
- asked by Dr. Wolfgang Hintze (3 votes)
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[Implementing t-SNE (t-Distributed Stochastic Neighbor Embedding)] http://mathematica.stackexchange.com/questions/137955/implementing-t-sne-t-distributed-stochastic-neighbor-embedding
Context
Six months ago @M.R. asked about an implementation of the t-Distributed Stochastic Neighbor Embedding (t-SNE) algorithm by van der Maaten and Hinton (2008). (@M.R.'s question) @Alexey ...
- asked by SumNeuron (3 votes)
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[Is there an easy way to to collect a large number variables into a list or list of lists?] http://mathematica.stackexchange.com/questions/138225/is-there-an-easy-way-to-to-collect-a-large-number-variables-into-a-list-or-list
I have a large number of variables in a notebook from a data analysis routine, the results of which now need to be fed through a mathematical model and various items for visualization.
For example, ...
- asked by Joe Kissling (2 votes)
================================== Top new questions this week: ==================================
[How to generate a mesh with quadrilateral elements?] http://mathematica.stackexchange.com/questions/137479/how-to-generate-a-mesh-with-quadrilateral-elements
I have the following code that generates a finite element mesh:
Needs["NDSolve`FEM`"] order = 2; mesh = ToElementMesh[ DiscretizeGraphics[ GraphicsComplex[{{0, 4}, {5, 4}, {5, 0}, {8, 0}, {8, ...
- asked by Diogo (13 votes), answered by Young (12 votes)
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[Why can’t I plot Log[Gamma[x]] for x > 170?] http://mathematica.stackexchange.com/questions/137666/why-cant-i-plot-loggammax-for-x-170
Bug introduced in 11.0
For some reason I can’t plot Log[Gamma[x]] for values of x larger than approximately 170:
Plot[Log[Gamma[x]], {x, 130, 200}, PlotRange -> All]
It works perfectly well ...
- asked by Felix (11 votes), answered by Szabolcs (12 votes)
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[Finding the number of odd quintinomial coefficients] http://mathematica.stackexchange.com/questions/137692/finding-the-number-of-odd-quintinomial-coefficients
I am searching for the number of odd coefficients of
\(\qquad (x^4 + x^3 + x^2 + x + 1)^n\)
for arbitrary \(n\).
It took some hours to compute the result for \(n=12207\). There are \(16333\) odd ...
- asked by Jenny_mathy (10 votes), answered by Carl Woll (15 votes)
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[Possible bug with RegionPlot] http://mathematica.stackexchange.com/questions/137273/possible-bug-with-regionplot
RegionPlot[ImplicitRegion[(2 x - 1)/(x - 1) < 3/2, {x, y}], PlotRange -> {{-9, 9}, {-9, 9}}]
Just checking whether anyone else can replicate this. Can anybody confirm such behavior and, ...
- asked by mathe (10 votes), answered by Jason B. (8 votes)
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[List processing] http://mathematica.stackexchange.com/questions/137306/list-processing
Suppose I have a list that looks like the following (Town names and total distance to that town)
resupply = { {"Coleman", 0}, {"Highwood House", 106}, {"Canmore", 229}, {"Exshaw", 245}, ...
- asked by Tom De Vries (9 votes), answered by Kuba (19 votes)
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[How to superimpose plots and graphics in the same coordinate system?] http://mathematica.stackexchange.com/questions/137408/how-to-superimpose-plots-and-graphics-in-the-same-coordinate-system
NB: I am aware that "plots" are graphics too, so the title would be more precisely worded if "graphics" were replaced by "non-plot graphics".
EDIT: I have edited my original example to make the ...
- asked by kjo (8 votes), answered by Bob Hanlon (5 votes)
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[Unit tests for Graphics or FE boxes] http://mathematica.stackexchange.com/questions/137541/unit-tests-for-graphics-or-fe-boxes
Consider the following expression with bad syntax:
Graphics[foo]
How can I detect the error and retrieve the error message programmatically, so I can check for it in unit tests?
- asked by Szabolcs (7 votes), answered by rcollyer (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Labeling individual curves in Mathematica] http://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (47 votes), answered by Artes (38 votes)
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[Why this real integral yields imaginary results?] http://mathematica.stackexchange.com/questions/127301/why-this-real-integral-yields-imaginary-results
Integrate[(y - y^2 + x - x^2 + 2*x*y)/(1 - x - y),{x,0,1},{y, 0, 1}]
The above integral yields -1-4I/3 in Mathematica. Since the integrand is real (although divergent at some points), how does ...
- asked by Chong Wang (16 votes), answered by bbgodfrey (19 votes)
================================== Can you answer these? ==================================
[How to convert ‘LogTicks[0, 2][[1, 2]]‘ to a regular number] http://mathematica.stackexchange.com/questions/137208/how-to-convert-logticks0-21-2-to-a-regular-number
I want to convert the \(10^i\) tick labels generated by LogTicks of the CustomTicks package to regular numbers. The first tick label is in element [[1,2]] of the object generated by LogTicks. FullForm ...
- asked by Felix (1 vote)
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[Solving the Euler-Lagrange equation with NDSolve‘ProcessEquations] http://mathematica.stackexchange.com/questions/137292/solving-the-euler-lagrange-equation-with-ndsolveprocessequations
I would like to compute the shortest distance between a number on pairs of points on a 2-dimensional Riemanniann statistical manifold (Negative Binomial distributions manifold, equipped with the Rao’s ...
- asked by C. Manté (1 vote)
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[Constraining the independent variable in a control system] http://mathematica.stackexchange.com/questions/137581/constraining-the-independent-variable-in-a-control-system
For an analog closed loop feedback control, I can do the following to model the response of a second-order physical system with an order 1 zeros polynomial to a step disturbance. I have a proportional ...
- asked by David Ollodart (2 votes)
================================== Top new questions this week: ==================================
[Code that generates a mandala] http://mathematica.stackexchange.com/questions/136974/code-that-generates-a-mandala
My little brother asked me to print original mandalas for coloring. I would like some idea on how to create them, but without color, so he can color them.
examples
- asked by zeros (31 votes), answered by Anton Antonov (48 votes)
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[How to make Mathematica variables declarative instead of just-in-time?] http://mathematica.stackexchange.com/questions/136833/how-to-make-mathematica-variables-declarative-instead-of-just-in-time
Is there a way to have Mathematica at the notebook level (SetOptions[EvaluationNotebook[], CellContext -> Notebook]) only uses a set of declared variables in the notebook context. Any variables ...
- asked by Edmund (27 votes), answered by rcollyer (25 votes)
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[Shorthand for map at level 2] http://mathematica.stackexchange.com/questions/136751/shorthand-for-map-at-level-2
I love the shorthand /@. It is amazing for readability (and laziness when typing). However, right now I find that I need Map at level 2, i.e. Map[f, List[List[a,b],List[c,d]], {2}], a lot and I'd wish ...
- asked by Kvothe (16 votes), answered by Mr.Wizard (19 votes)
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[Proteins, ProteinData, WolframAlpha] http://mathematica.stackexchange.com/questions/136741/proteins-proteindata-wolframalpha
Apologies in advance, this is the first I’ve messed with ProteinData and access through WolframAlpha, so clearly I may not know how Mathematica and Alpha decide on what is the ’right way’ to ask ...
- asked by flip (15 votes), answered by J. M. (10 votes)
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[Simplifying a reverse Fold for a Query] http://mathematica.stackexchange.com/questions/136856/simplifying-a-reverse-fold-for-a-query
Is there a simpler way to parametrize this tail-recursive expression to be applied as a Query (for processing a nested Association)? The pattern is shown by example with first 3 levels:
- asked by alancalvitti (11 votes), answered by Edmund (10 votes)
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[Where is Abbott? How to make logograms from the film "Arrival"?] http://mathematica.stackexchange.com/questions/137156/where-is-abbott-how-to-make-logograms-from-the-film-arrival
The film Arrival showed Wolfram Language code in action analysing alien logograms. A recent blog describes some details and mentions a live-coding video by Christopher Wolfam. See also Stephen ...
- asked by KennyColnago (8 votes), answered by KennyColnago (10 votes)
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[How to implement neural style transfer?] http://mathematica.stackexchange.com/questions/136704/how-to-implement-neural-style-transfer
In the paper A Neural Algorithm of Artistic Style, Leon A. Gatys et all. describe a process of extracting the content and style vectors from an image separately. They use this technique to generate ...
- asked by M.R. (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to add a vertical line to a plot] http://mathematica.stackexchange.com/questions/3561/how-to-add-a-vertical-line-to-a-plot
In the plot below I would like to add two vertical lines at \(x = \frac {\pi }{15} \pm \frac {1}{20}\). How can I do that?
f[x_] := (x^2 z)/((x^2 - y^2)^2 + 4 q^2 x^2) /. {y -> /15, z -> 1, q -> ...
- asked by sjdh (32 votes), answered by Ajasja (48 votes)
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[Calculate the 2D Fourier transform of an Image] http://mathematica.stackexchange.com/questions/29203/calculate-the-2d-fourier-transform-of-an-image
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase spectrum, as well as reconstruct the ...
- asked by user8727 (5 votes), answered by Nasser (27 votes)
================================== Can you answer these? ==================================
[Nonsparse sparse array crashes kernel on windows] http://mathematica.stackexchange.com/questions/136835/nonsparse-sparse-array-crashes-kernel-on-windows
On win 10, 64 bit, version 11.0.1, my kernel just started crashing for no reason as for as I can see. Does/should the following crash your kernel?
sparse = SparseArray[ArrayRules[RandomInteger[{1, ...
- asked by Coolwater (6 votes)
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[How to visualize the vorticity of a 3D velocity field?] http://mathematica.stackexchange.com/questions/136917/how-to-visualize-the-vorticity-of-a-3d-velocity-field
I have a snapshot of a system with 50 particles.
The snapshot is a list of 3 coordinates and 3 velocities per each particle. Namely, \((x,y,z,\dot {x},\dot {y},\dot {z})\), which AKA phase space ...
- asked by 0x90 (5 votes)
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[Finding line segments on the image by using ImageLines] http://mathematica.stackexchange.com/questions/136795/finding-line-segments-on-the-image-by-using-imagelines
There is an image from wolfram documentation
I want to find and highlight lines on the following image
I tried:
img = Import["http://imgur.com/NbNwYWC.png"] lines = ImageLines[EdgeDetect[img], ...
- asked by vito (3 votes)
================================== Top new questions this week: ==================================
[How to get a specified number of points that are nearly equally spaced in a closed rectangle] http://mathematica.stackexchange.com/questions/136447/how-to-get-a-specified-number-of-points-that-are-nearly-equally-spaced-in-a-clos
TriangulateMesh is almost the right tool for this problem. For example,
numb = 113; region = BoundaryMeshRegion[{{0, 0}, {3, 0}, {3, 1}, {0, 1}}, Line[{1, 2, 3, 4, 1}]]; mesh = ...
- asked by Ted Ersek (17 votes), answered by Szabolcs (15 votes)
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[Tutorial on creating publication quality documents in Mathematica?] http://mathematica.stackexchange.com/questions/136426/tutorial-on-creating-publication-quality-documents-in-mathematica
Are there books or tutorials that walk one through creating a professional publication quality notebook?
For example, I would like to create a two column article using an IEEE format. Is this ...
- asked by Doug Kimzey (13 votes)
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[Type conversions] http://mathematica.stackexchange.com/questions/136476/type-conversions
I have the following list, each element of which is of type string:
"abc", "def","2","ghi","7"
Is there an efficient way to arrive at:
"abcdef", 2,"ghi",7
where adjacent alphabetic elements ...
- asked by Suite401 (12 votes), answered by Bob Hanlon (8 votes)
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[Alternatives and the Flat attribute] http://mathematica.stackexchange.com/questions/136157/alternatives-and-the-flat-attribute
When a head has the attribute Flat then the pattern matcher is able to pick out a sublist of its arguments, even though the structure doesn’t match:
SetAttributes[f, Flat]; f[a, b, c, d] /. f[a, b] ...
- asked by Martin Ender (11 votes)
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[Assign names to Dataset columns] http://mathematica.stackexchange.com/questions/136422/assign-names-to-dataset-columns
I am constructing a dataset like so:
data = Dataset[AssociationThread[Keys[characterCounts], charFrequencies]]
which gives me a dataset that looks like this:
This is all fine, but as you can ...
- asked by damjandd (10 votes), answered by Kuba (10 votes)
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[Dataset interferes with SeedRandom] http://mathematica.stackexchange.com/questions/136339/dataset-interferes-with-seedrandom
This seems like a pretty awful bug:
SeedRandom[1]; RandomInteger[10, 10] Out: {1,4,0,7,0,0,8,6,0,4} While: SeedRandom[1]; Dataset[<|a -> 1, b -> 2|>]; RandomInteger[10, 10] Out: ...
- asked by Mohammed AlQuraishi (10 votes)
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[Problem with integrating DiracDelta] http://mathematica.stackexchange.com/questions/136214/problem-with-integrating-diracdelta
I thought I had found a bug in Mathematica and reported it already in version 9, since it wasn’t fixed in version 10 or 11 I reported it two more times but I never get any reply whatsoever so I’m ...
- asked by user3777022 (10 votes), answered by Julien Kluge (8 votes)
================================== Greatest hits from previous weeks: ==================================
[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (30 votes), answered by Artes (22 votes)
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[How to create a fascinating QR code like this?] http://mathematica.stackexchange.com/questions/120041/how-to-create-a-fascinating-qr-code-like-this
Check the facinating QRCode in my profile page here
You can find that this QRCode is some sort of intriguing as the QRCode is a IMAGE ITSELF!!!
So my question is, how to create such a QRCode ...
- asked by Wjx (24 votes), answered by Wjx (19 votes)
================================== Can you answer these? ==================================
[How to Approximate at Non-differentiable Point (forced Series Expansion around Branch Cut)] http://mathematica.stackexchange.com/questions/136395/how-to-approximate-at-non-differentiable-point-forced-series-expansion-around-b
I need a numerical approximation around some functions at \(x = 0^{-}\) from the left side, where \(x = 0\) is unfortunately the right end of the domain (in the reals) so the functions are not ...
- asked by Lee David Chung Lin (3 votes)
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[3D reconstruction of a 2D SEM image] http://mathematica.stackexchange.com/questions/136284/3d-reconstruction-of-a-2d-sem-image
I am curious if Mathematica could do reconstruction of a 2D SEM image into a 3D. It is the same what can be done by MountainsMap SEM software http://www.digitalsurf.fr/en/mntsem.html
Visually it ...
- asked by Viacheslav Plotnikov (4 votes)
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[Help needed in Understand the following program in solving a stiff nonlinear differential equation] http://mathematica.stackexchange.com/questions/136607/help-needed-in-understand-the-following-program-in-solving-a-stiff-nonlinear-dif
I am trying to solve a particular Cauchy problem given by
I found from a particular paper that the solutions looks like
For the auxiliary conditions
For only specific values of \(a_{i}\)
I ...
- asked by kernel_panic (1 vote)
================================== Top new questions this week: ==================================
[My Girlfriend is going to prison...Save her with Math] http://mathematica.stackexchange.com/questions/135937/my-girlfriend-is-going-to-prison-save-her-with-math
Salacious title, but true story.
dmethyl1 = { {0, 0}, {.25, 1}, {.5, 7}, {1, 26}, {1.5, 40}, {2, 45}, {2.5, 45}, {3, 44}, {3.5, 44}, {4, ...
- asked by Prisoners Dilema (35 votes), answered by bobthechemist (22 votes)
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[How to use the iterator in Mathematica] http://mathematica.stackexchange.com/questions/135916/how-to-use-the-iterator-in-mathematica
I find the Mathematica has the iterator data structure. We can build some iterators like this:
Constant iterator
GeneralUtilities`ConstantIterator[5]
Key value iterator
...
- asked by yode (15 votes), answered by Michael E2 (15 votes)
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[SquaresR memory leak?] http://mathematica.stackexchange.com/questions/135781/squaresr-memory-leak
I have tried the following code in Mathematica 11.0.1.0 on my MacBook:
$HistoryLength = 0; ClearAll["Global`*"]; ClearSystemCache[]; MemoryInUse[] AbsoluteTiming[Do[SquaresR[2, i], {i, 1000000}];]
...
- asked by outofmemory (12 votes), answered by Mr.Wizard (18 votes)
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[SetOptions locally?] http://mathematica.stackexchange.com/questions/136005/setoptions-locally
Is there a way to SetOptions locally? For example, I have a Module and inside it I am doing a lot of Plots with similar options. If I do a SetOptions[Plot, ...] inside the Module, the change ...
- asked by becko (11 votes), answered by J. M. (12 votes)
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[Understanding simple numerical calculation] http://mathematica.stackexchange.com/questions/135636/understanding-simple-numerical-calculation
I am trying to understand why N[0.1]//FullForm returns 0.1’ (A). Indeed, \(0.1\) in base two is \(0.000110011001100110011...\). If I truncate this number to the first 52 digits and convert it back to base ...
- asked by anderstood (11 votes), answered by Michael E2 (18 votes)
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[How to work with Date calculations?] http://mathematica.stackexchange.com/questions/135713/how-to-work-with-date-calculations
I have never worked using the DateObject function
But I suspect there must be a (easy) way of doing it.
I want to find out, when in the future, from which point, that the cumulative days of not ...
- asked by Chen Stats Yu (10 votes), answered by Simon Woods (12 votes)
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[How to riffle matrices] http://mathematica.stackexchange.com/questions/135848/how-to-riffle-matrices
I have four matrices
m = {{M11, M12, M13}, {M21, M22, M23}, {M31, M32, M33}}; n = {{N11, N12, N13}, {N21, N22, N23}, {N31, N32, N33}}; p = {{P11, P12, P13}, {P21, P22, P23}, {P31, P32, P33}}; q = ...
- asked by Kowalski (8 votes), answered by Carl Woll (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Is there an open source implementation of Mathematica-the-language?] http://mathematica.stackexchange.com/questions/4454/is-there-an-open-source-implementation-of-mathematica-the-language
I’ve seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
- asked by sblom (81 votes), answered by Simon (64 votes)
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[Is it possible to export the equations from Mathematica to MATLAB?] http://mathematica.stackexchange.com/questions/14035/is-it-possible-to-export-the-equations-from-mathematica-to-matlab
Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?
- asked by Seyhmus Güngören (27 votes), answered by R. M. (35 votes)
================================== Can you answer these? ==================================
[Gap in X-axis when using LogLinearPlot] http://mathematica.stackexchange.com/questions/136025/gap-in-x-axis-when-using-loglinearplot
Basically, this is the plot that comes out when I choose
Frame -> True Due to my need of labeling the axes. Is there a way to get rid off of that annoying gap? Here is the figure Here is the ...
- asked by Alan Turing (1 vote)
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[When solving a heavy PDE Mathematica falls out: what can be done] http://mathematica.stackexchange.com/questions/135819/when-solving-a-heavy-pde-mathematica-falls-out-what-can-be-done
I am solving a heavy PDE. The mesh is huge, and Mma falls out after few tens of minutes solving: the cell becomes inactive, kernel (pressumably) quits, all variables turn blue.
My question is, what ...
- asked by Alexei Boulbitch (3 votes)
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[Exporting Cellular Automata Image Sequence] http://mathematica.stackexchange.com/questions/136068/exporting-cellular-automata-image-sequence
I am trying to make an animation in Adobe After Effects utilizing cellular automata. I would like to export each step (say 500 steps) as a high resolution vector image so that I can combine them as an ...
- asked by Ryan Conover (1 vote)
================================== Top new questions this week: ==================================
[How to rotate the curve but not the axes?] http://mathematica.stackexchange.com/questions/135376/how-to-rotate-the-curve-but-not-the-axes
I have a such graphic:
data = {{0, 5}, {1.9, 7.5}, {0, 12}, {-5, 15.5}, {-1.2, 33.4}}; p=Plot[Interpolation[Reverse /@ data, x, InterpolationOrder -> 2], {x, 0, 55}, Epilog -> {Red, ...
- asked by yode (11 votes), answered by kglr (11 votes)
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[Function to draw densely interconnected layers in graph (e.g., neural net)] http://mathematica.stackexchange.com/questions/135354/function-to-draw-densely-interconnected-layers-in-graph-e-g-neural-net
I can use Graph[] to manually draw the shape of a very simple set of interconnected layers (for instance, a small neural network):
Graph[{1 -> 3, 2 -> 3, 1 -> 5, 2 -> 5, 1 -> 4, 2 ...
- asked by Larry OBrien (11 votes), answered by kglr (12 votes)
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[An Intersection function on lists that saves intersection positions] http://mathematica.stackexchange.com/questions/135583/an-intersection-function-on-lists-that-saves-intersection-positions
I would like an intersection function on lists like Intersection that also stores the coordinates of the intersections. For instance for a,b,c and b,c,e would give something like ...
- asked by Kvothe (9 votes), answered by ciao (9 votes)
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[Combining lists of lists with random structure] http://mathematica.stackexchange.com/questions/135238/combining-lists-of-lists-with-random-structure
I have two lists which I would like to combine. One is of a random structure, which might be:
l1={{3, 2, 4, 2}, {2, 3}, {4, 3}, {{2, 2}}, {{3, 3}}, {3, 2}}
where the elements in each sublist may ...
- asked by Jonathan Shock (9 votes), answered by Mr.Wizard (7 votes)
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[Slicing an Association with named key span without normalizing?] http://mathematica.stackexchange.com/questions/135092/slicing-an-association-with-named-key-span-without-normalizing
Is there way to slice an Association with named key span?
Span currently doesn’t accept named keys:
<|"z" -> 1, "x" -> 2, "b" -> 3, "a" -> 4|> // Query["x" ;; "a"]
- asked by alancalvitti (9 votes), answered by Mr.Wizard (11 votes)
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[Finding Ramanujan’s taxicab numbers] http://mathematica.stackexchange.com/questions/135128/finding-ramanujans-taxicab-numbers
How to find Hardy-Ramanujan Numbers by using Mathematica?
Definition: Taxicab number is defined as the smallest number that can be expressed as a sum of two positive cubes in \(n\) distinct ways. ...
- asked by vito (9 votes), answered by vito (6 votes)
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[Area of surface of revolution] http://mathematica.stackexchange.com/questions/135358/area-of-surface-of-revolution
I am asked to rotate the curve \(y=\sqrt {4-x^2}\) from \(x=-1\) to \(x=1\) about the x-axis and find the area of the surface. I was able to use RevolutionPlot3D to show the surface.
RevolutionPlot3D[Sqrt[4 ...
- asked by David (7 votes), answered by corey979 (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Entering numbers in Scientific Notation?] http://mathematica.stackexchange.com/questions/36792/entering-numbers-in-scientific-notation
I need to play with a lot of powers such as 10^-3. 1E-3 does not work for it. Is there any short form for it?
- asked by hhh (23 votes), answered by Rahul (32 votes)
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[xkcd-style graphs] http://mathematica.stackexchange.com/questions/11350/xkcd-style-graphs
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over PlotLegends to have these ...
- asked by Amatya (532 votes), answered by Simon Woods (385 votes)
================================== Can you answer these? ==================================
[Amelioration of a Karush-Kuhn-Tucker nice code] http://mathematica.stackexchange.com/questions/135220/amelioration-of-a-karush-kuhn-tucker-nice-code
In what concerns the resolution of a Karush-Kuhn-Tucker condition, this wonderful code borrowed to Parreiras (The Mathematica Journal 16 2014) which is a correction of another code by Kampas (The ...
- asked by cyrille.piatecki (4 votes)
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[URLDownload aborts prematurely] http://mathematica.stackexchange.com/questions/135355/urldownload-aborts-prematurely
So I’ve been trying to automate the download and build of various large packages for hooking Mathematica into extensions but the downloads continually finish prematurely.
Edit: first example was just ...
- asked by MB1965 (2 votes)
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[Simplify an integer expression involving Ceiling and Root[] of third degree polynomial] http://mathematica.stackexchange.com/questions/135566/simplify-an-integer-expression-involving-ceiling-and-root-of-third-degree-poly
I would like to simplify the following expression
Ceiling[ToRadicals[Root[90 - 6 num + 65 #1 + 12 #1^2 + #1^3 &, 1]]]
with num an integer greater than or equal to 16. I tried using ...
- asked by Piruzzolo (1 vote)
================================== Top new questions this week: ==================================
[Is there any possibility to implement a structure like a ProgressIndicator into NDSolve?] http://mathematica.stackexchange.com/questions/134787/is-there-any-possibility-to-implement-a-structure-like-a-progressindicator-into
It is already formulated in the title. NDSolve takes sometimes a considerable piece of time. It would be very practical to have some information on how long it is still to wait. So, any ideas?
To ...
- asked by Alexei Boulbitch (20 votes), answered by user21 (16 votes)
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[This integral is divergent. How to use NIntegrate to see how it grows?] http://mathematica.stackexchange.com/questions/135073/this-integral-is-divergent-how-to-use-nintegrate-to-see-how-it-grows
I am trying to get information on the following integral: \[ \int _{\pi -0.3}^{\pi -\epsilon } \frac {1}{(3+\cos {x})\sqrt {(3+\cos {x})^2-4}} \]
The lower limit is somewhat arbitrary; the point is that ...
- asked by Gelasio Salazar (10 votes), answered by Michael E2 (6 votes)
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[Call a Haskell DLL from Mathematica] http://mathematica.stackexchange.com/questions/134913/call-a-haskell-dll-from-mathematica
Looking for a way to call a Haskell DLL from Mathematica, I’ve stumbled on this, for GNU R:
http://neilmitchell.blogspot.com.br/2011/10/calling-haskell-from-r.html
It is (to me) a beautiful example ...
- asked by Rand (10 votes), answered by WReach (11 votes)
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[Product of set elements not exceeding a bound] http://mathematica.stackexchange.com/questions/134743/product-of-set-elements-not-exceeding-a-bound
I have a set of distinct positive integers l (if you wish, you may assume it is a list ordered by size), and a bound lim. In general, l has thousands of elements, but all are at most equal to lim. I ...
- asked by rogerl (10 votes), answered by george2079 (4 votes)
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[How does Mathematica solve a certain differential equation?] http://mathematica.stackexchange.com/questions/135055/how-does-mathematica-solve-a-certain-differential-equation
I was trying to solve a nonlinear differential equation with the following code.
DSolve[3*x^2/D[u[x, y], x] + 3*y^2/D[u[x, y], y] == -1, u, {x, y}] And I got the following output: {{u -> ...
- asked by usr109876787 (8 votes), answered by Michael E2 (12 votes)
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[How to cross-compile LibraryLink code for multi-platform distribution] http://mathematica.stackexchange.com/questions/135022/how-to-cross-compile-librarylink-code-for-multi-platform-distribution
I am running Mathematica on a Windows 10 machine and I would like to develop a package for public distribution. Most of the package will be Mathematica code, but some timing-critical parts should be ...
- asked by Ben Niehoff (8 votes)
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[Plotting difference between two Half Normal Distributions] http://mathematica.stackexchange.com/questions/134824/plotting-difference-between-two-half-normal-distributions
I am new to Mathematica, and this question may reflect that.
I am trying to plot the probability density function of a random variable which equals the difference between two independent random ...
- asked by user120911 (8 votes), answered by Jim Baldwin (9 votes)
================================== Greatest hits from previous weeks: ==================================
[How to create a fascinating QR code like this?] http://mathematica.stackexchange.com/questions/120041/how-to-create-a-fascinating-qr-code-like-this
Check the facinating QRCode in my profile page here
You can find that this QRCode is some sort of intriguing as the QRCode is a IMAGE ITSELF!!!
So my question is, how to create such a QRCode ...
- asked by Wjx (24 votes), answered by Wjx (19 votes)
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[Find the 5566th digit after the decimal point of 7/101] http://mathematica.stackexchange.com/questions/125025/find-the-5566th-digit-after-the-decimal-point-of-7-101
I want to find the 5566th digit after the decimal point of 7/101. I input the following code into Mathematica 11:
Mod[IntegerPart[7/101*10^5566], 10]
The output is 6, which is the correct answer. ...
- asked by Wei-Cheng Liu (17 votes), answered by yarchik (19 votes)
================================== Can you answer these? ==================================
[Inset thickness and ImageResolution] http://mathematica.stackexchange.com/questions/134738/inset-thickness-and-imageresolution
I have noticed that when I export something with an Inset objects,
pp[t_] := Plot[Sin[x], {x, -10, 10}, Epilog -> {Inset[ Framed[ Text[Style[HoldForm["t=" t], ...
- asked by usumdelphini (4 votes)
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[Find the parameter values for my matrix for it to have imaginary eigenvalues] http://mathematica.stackexchange.com/questions/134909/find-the-parameter-values-for-my-matrix-for-it-to-have-imaginary-eigenvalues
Say I have a matrix that depends on a parameter \(u\). The following may be an example:
a = {{1, u^3 + 2, 1}, {0, 1, u}, {1/u^2, 0, 1}};
My real problem is 12x12 matrix with difficult parametric ...
- asked by Mirko Aveta (1 vote)
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[NotebookEvaluate breaks notebook’s context] http://mathematica.stackexchange.com/questions/135025/notebookevaluate-breaks-notebooks-context
Here is an example of a notebook with local context:
nb = CreateDocument[{ ExpressionCell[Defer @ CurrentValue[EvaluationNotebook[], CellContext], "Input"], ExpressionCell[Defer @ $Context, ...
- asked by Kuba (2 votes)
================================== Top new questions this week: ==================================
[Why should I avoid the For loop in Mathematica?] http://mathematica.stackexchange.com/questions/134609/why-should-i-avoid-the-for-loop-in-mathematica
Some people advise against the use of For loops in Mathematica. Why? Should I heed this advice? What is wrong with For? What should I use instead?
- asked by Szabolcs (27 votes), answered by Szabolcs (36 votes)
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[Is there a style sheet that can be used to generate Stack Exchange input?] http://mathematica.stackexchange.com/questions/134518/is-there-a-style-sheet-that-can-be-used-to-generate-stack-exchange-input
It would be convenient if there were a style sheet that automatically indented input cells, and automatically commented output cells, so that one could generate a stack exchange response in WL, and ...
- asked by Carl Woll (24 votes), answered by Carl Woll (21 votes)
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[Function to create a path made of horizontal and vertical lines between a number of points] http://mathematica.stackexchange.com/questions/134424/function-to-create-a-path-made-of-horizontal-and-vertical-lines-between-a-number
I would like to create a function where I can define which case I want to use to create a path.
p1 = {40, 48}; p2 = {50, 116}; p3 = {63, 160}; listPurple = Symbol["p" <> ToString[#]] & /@ ...
- asked by Maria Regina (16 votes), answered by corey979 (15 votes)
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[How to wrap a crumpled paper over a surface?] http://mathematica.stackexchange.com/questions/134514/how-to-wrap-a-crumpled-paper-over-a-surface
My initial question was about the making of a crumpled paper. After reading this article suggested by J.M. and little more browsing (kind of random walk you do on a Saturday) I thought about expanding ...
- asked by Sumit (8 votes)
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[Would like input and output printed on same line, w/o needing extra syntax] http://mathematica.stackexchange.com/questions/134406/would-like-input-and-output-printed-on-same-line-w-o-needing-extra-syntax
SUMMARY
I’d like to get MMA to automatically print both input and output on the same line, in TraditionalForm, without having to add any extra syntax. Further, I’d like the output to be fully ...
- asked by theorist (8 votes), answered by Simon Rochester (4 votes)
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[Issue with Cell Frames in version 11] http://mathematica.stackexchange.com/questions/134665/issue-with-cell-frames-in-version-11
Since upgrading to version 11, all of my notebooks now have cell frames are either missing the top or bottom part. Is anyone else experiencing this? Is there a way to fix this? Is this considered ...
- asked by Michael McCain (7 votes), answered by MB1965 (5 votes)
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[How to speed up this code about a triple integral?] http://mathematica.stackexchange.com/questions/134477/how-to-speed-up-this-code-about-a-triple-integral
How to speed up this code? It’s unbelievably slow!!! My solution with pen and paper is faster.
Clear[R, h]; Integrate[ Integrate[ Integrate[1, {z, h, Sqrt[R^2 - x^2 - y^2]}, Assumptions -> ...
- asked by Mika Ike (7 votes), answered by corey979 (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Exporting graphics to PDF - huge file] http://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[], r Sin[], r^2}, {r, 0, ...
- asked by Matthew Leingang (89 votes), answered by Heike (75 votes)
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[Entering numbers in Scientific Notation?] http://mathematica.stackexchange.com/questions/36792/entering-numbers-in-scientific-notation
I need to play with a lot of powers such as 10^-3. 1E-3 does not work for it. Is there any short form for it?
- asked by hhh (21 votes), answered by Rahul (30 votes)
================================== Can you answer these? ==================================
[How to specify halting states when using function TuringMachine?] http://mathematica.stackexchange.com/questions/134628/how-to-specify-halting-states-when-using-function-turingmachine
The function TuringMachine generates a list that represents the evolution of a Turing Machine given a rule that specifies its behaviour (i.e. set of instructions).
For example, the following rule ...
- asked by Lili (4 votes)
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[Can I use Mathematica for the symbolic verification of cases of a general problem?] http://mathematica.stackexchange.com/questions/134515/can-i-use-mathematica-for-the-symbolic-verification-of-cases-of-a-general-proble
I have never used Mathematica before, but I am contemplating using it to solve this problem for a simple case of \(f(x) = C, 1<x<2\) and \(= 0\) and \(= 0\). I can easily get \(\hat {f}\), the Fourier transform of ...
- asked by Rajesh Dachiraju (2 votes)
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[Antialiasing in Plot3D doesn’t work well] http://mathematica.stackexchange.com/questions/134612/antialiasing-in-plot3d-doesnt-work-well
My code is very simple:
Style[Plot3D[Cos[x + 0*y], {x, -10, 10}, {y, -2, 42}, Mesh -> None], Antialiasing -> True]
There seems some ripple on the top of the figure and I doubt whether it ...
- asked by user29114 (1 vote)
================================== Top new questions this week: ==================================
[Partitioning a number into consecutive integers] http://mathematica.stackexchange.com/questions/134252/partitioning-a-number-into-consecutive-integers
Consider n=45; then
\[1+2+3+4+5+6+7+8+9=45\] \[5+6+7+8+9+10=45\] \[7+8+9+10+11=45\] \[14+15+16=45\] \[22+23=45\]
Question: how to find all representations of a given positive integer n as a sum of ...
- asked by corey979 (17 votes), answered by corey979 (19 votes)
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[Why is my GIF shaky?] http://mathematica.stackexchange.com/questions/134272/why-is-my-gif-shaky
As you can see, the circles are shaking vertically as they approaching each other. Why is that?
The code:
g = Table[ Graphics[{Thickness[0.01], Table[{ Circle[{0 + x, 0}, r], ...
- asked by Jason (13 votes), answered by Sumit (10 votes)
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[Can Mathematica edit large binary files in-place?] http://mathematica.stackexchange.com/questions/133973/can-mathematica-edit-large-binary-files-in-place
I have a very large binary data file (several hundred GB) which I would like to edit using Mathematica. The only edits required are a few isolated byte replacementsno insertions or deletions. Is it ...
- asked by David Zhang (12 votes)
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[Solving chess bishop problem] http://mathematica.stackexchange.com/questions/134218/solving-chess-bishop-problem
I have generalized the problem in this way where I have a list
list=Tuples[Range[8],2]
I want to find the largest sublist in which the addition of the two entries for any two elements of the ...
- asked by m. bubu (10 votes), answered by ubpdqn (11 votes)
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[How to get such rule with a elegant method] http://mathematica.stackexchange.com/questions/134227/how-to-get-such-rule-with-a-elegant-method
I have two lists:
list={{1,2,3,5},{5,3,9,11,12},{5,9,10,16}}; list2={{7,89},{96,5},{-6,-98}}; This is the expected result. {{1->{7,89},2->{7,89},3->{7,89},5->{7,89}}, ...
- asked by yode (9 votes), answered by Mr.Wizard (9 votes)
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[Pseudo-currying in one line] http://mathematica.stackexchange.com/questions/134315/pseudo-currying-in-one-line
Often when I’m writing OOP code using an object-manager association I find myself doing something akin to currying the arguments to some form of delegate object or head. (Building a one-argument ...
- asked by MB1965 (8 votes), answered by Bob Hanlon (8 votes)
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[How to create a multi-graphics plot (i.e. the decomposition of phase plane portrait) with well-organized structure?] http://mathematica.stackexchange.com/questions/134228/how-to-create-a-multi-graphics-plot-i-e-the-decomposition-of-phase-plane-portr
Background
I am trying to create a three-graphics plot using the command GraphicsGrid[] to show the decomposition of the phase plane portrait; unfortunately, the plot created is very ugly since the ...
- asked by Liang.X (8 votes), answered by Sumit (8 votes)
================================== Greatest hits from previous weeks: ==================================
[Finding Limits in several variables] http://mathematica.stackexchange.com/questions/21544/finding-limits-in-several-variables
Is there a way to find a limit of a multivariable function, like
\[\lim _{(x,y)\to (0,0)} f(x,y)\] with Mathematica?
When \(f\) is continuous, we can use \[\lim _{(x,y)\to (0,0)} \] ...
- asked by Dominic Michaelis (21 votes), answered by whuber (32 votes)
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[Can Mathematica do symbolic linear algebra?] http://mathematica.stackexchange.com/questions/3242/can-mathematica-do-symbolic-linear-algebra
For instance, is there some way I can say "let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ...
- asked by nikie (38 votes), answered by helen (19 votes)
================================== Can you answer these? ==================================
[Graph that shows how symbols are used in an expression] http://mathematica.stackexchange.com/questions/134180/graph-that-shows-how-symbols-are-used-in-an-expression
I would like to make a graph to show how symbols build up an expression. For example, the matrix multiplication
$$ \left( \begin{array}{ccc} a & b & c \\ d & e & f \\ \end{array} ...
- asked by ConvexMartian (4 votes)
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[Question about DynamicModule] http://mathematica.stackexchange.com/questions/134063/question-about-dynamicmodule
I have a such custom function:
MyCopy := DynamicModule[{from, to}, Print@Grid[{{FileNameSetter[Dynamic[from], "Directory"], Dynamic[from]}, {FileNameSetter[Dynamic[to], "Directory"], ...
- asked by yode (3 votes)
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[General solution of inscribed square problem] http://mathematica.stackexchange.com/questions/134237/general-solution-of-inscribed-square-problem
There is my earlier question about Inscribed square problem
Now I tried to find the general solution for any curve \(f(x,y)=0\).
For instance :
\(\qquad \left (x^2+y^2-1\right )^3-x^2 y^3=0\)
...
- asked by vito (5 votes)
================================== Top new questions this week: ==================================
[How can I work with RawArray?] http://mathematica.stackexchange.com/questions/133666/how-can-i-work-with-rawarray
RawArray seems to be able to efficiently hold integer and floating point data of various sizes.
What is RawArray good for? How can we use it?
- asked by Szabolcs (19 votes), answered by Szabolcs (15 votes)
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[Random points around the given curve] http://mathematica.stackexchange.com/questions/133682/random-points-around-the-given-curve
How to plot a random points around the following Helix curve?
ParametricPlot3D[{6 Cos[t], 6 Sin[t], t}, {t, -2 , 4 }, PlotTheme -> "Detailed", PlotStyle -> {Blue, Thickness[Large]}, ...
- asked by vito (14 votes), answered by J. M. (15 votes)
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[Intuition behind FoldPair and SequenceFold?] http://mathematica.stackexchange.com/questions/133625/intuition-behind-foldpair-and-sequencefold
In trawling through the documentation I’ve found the functions FoldPairList and SequenceFoldList. Examples are given of how to use FoldPairList:
Partition a list into sublists of different lengths ...
- asked by pdmclean (12 votes), answered by andre (4 votes)
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[Product of two lists] http://mathematica.stackexchange.com/questions/133723/product-of-two-lists
Please, for the two lists:
L1 := {{a, b}, {c, d}, {e, f}} L2 := {{g, h, i}, {j, k, q}} I need the result {{{a g, a h, a i}, {c g, c h, c i}, {e g, e h, e i}}, {{b j, b k, b q}, {d j, d k, d ...
- asked by Ali (11 votes), answered by xzczd (13 votes)
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[Is there something similar to seaborn stripplot in mathematica] http://mathematica.stackexchange.com/questions/133634/is-there-something-similar-to-seaborn-stripplot-in-mathematica
Is there something similar to seaborn stripplot in mathematica? The graph I am trying to make is like this:
- asked by Yordan (11 votes), answered by Brett Champion (12 votes)
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[Collapsible Tree] http://mathematica.stackexchange.com/questions/133492/collapsible-tree
Has somebody tried to program for data visualization an interactive Collapsible Tree like shown here: http://bl.ocks.org/mbostock/4339083. This implements the Reingold-Tilford algorithm.
...
- asked by mrz (8 votes)
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[FindDistributionParameters fails with custom distribution which cannot be evaluated symbolically] http://mathematica.stackexchange.com/questions/133456/finddistributionparameters-fails-with-custom-distribution-which-cannot-be-evalua
Context
I am interested in measuring the dark energy equation of state of the universe while fitting the PDF of density in cells. This involves fitting a one parameter PDF to some data.
Following ...
- asked by chris (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How can I draw the Olympic rings with Mathematica?] http://mathematica.stackexchange.com/questions/8885/how-can-i-draw-the-olympic-rings-with-mathematica
How can I draw the 5 interlocking Olympic rings with Mathematica?
(SVG version)
Edit
Hard choice, but some pretty cool answers here. I didn’t have 3D answers in mind when I posted the question, ...
- asked by Mike Honeychurch (42 votes), answered by cormullion (19 votes)
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[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (448 votes), answered by faysou (397 votes)
================================== Can you answer these? ==================================
[Symbolic Weak Form] http://mathematica.stackexchange.com/questions/133575/symbolic-weak-form
Usually I write the weak form by hand for my FEM code, but it’s a little annoying and mechanic sometimes.
So, I wonder, is there any way to generate the symbolic weak form in Mathematica? For ...
- asked by senseiwa (5 votes)
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[Why is Minimize spinning?] http://mathematica.stackexchange.com/questions/133789/why-is-minimize-spinning
The command
Minimize[a^2 + b^2 + c^2 + a*b + b*c + a*c - (a + b - c)*Sqrt[2 a*b + b*c + a*c] - (b + c - a)* Sqrt[2 b*c + b*a + a*c] - (a + c - b)*Sqrt[2 a*c + a*b + b*c], a >= 0 && b ...
- asked by user64494 (4 votes)
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[How to export an MXNet?] http://mathematica.stackexchange.com/questions/133857/how-to-export-an-mxnet
I was hoping there was some way to generate the .params and .json file needed to define an MXNet model, from a network trained using NetTrain[] in Mathematica:
I see these functions in the ...
- asked by user5601 (5 votes)
================================== Top new questions this week: ==================================
[Query: adding additional operator changes meaning of preceding operators] http://mathematica.stackexchange.com/questions/133124/query-adding-additional-operator-changes-meaning-of-preceding-operators
Consider the following query:
Range[5] // Query[Select[EvenQ] /* Append[1], f] (* {f[2], f[4], 1} *)
It selects the even numbers, applies f to them and finally appends 1 to the list. As expected, ...
- asked by WReach (15 votes), answered by WReach (15 votes)
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[Why does Mathematica think this series doesn’t converge?] http://mathematica.stackexchange.com/questions/132982/why-does-mathematica-think-this-series-doesnt-converge
Bug introduced in 10.0 and persisting through 11.0 (reported as CASE:3790525)
Here’s a simple series:
Sum[t^k DiscreteDelta[k]/k!,{k,0,Infinity}]
Mathematica says that it doesn’t converge. But ...
- asked by Ruslan (13 votes), answered by Jules Lamers (9 votes)
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[Joining two lists with relational operators] http://mathematica.stackexchange.com/questions/132928/joining-two-lists-with-relational-operators
I have two lists liste = {x, -y, y, -z} and listv = {1, -2, 3, -4}, which represent the inequities obtained evaluating liste - listv <= 0. How do I reassemble or join those two separate lists into ...
- asked by nanjun (13 votes), answered by Kuba (15 votes)
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[What assumptions do I need to make Mathematica integrate a function?] http://mathematica.stackexchange.com/questions/133052/what-assumptions-do-i-need-to-make-mathematica-integrate-a-function
When I feed Mathematica the following integral:
Integrate[Sqrt[(A - x) (B - x)/x], {x, 0, B}]
it spits it back out without evaluating it. However, it can evaluate the integral
Integrate[Sqrt[(2 - ...
- asked by user45146 (11 votes), answered by Artes (12 votes)
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[Do Apple Watch + Mathematica integrations still work?] http://mathematica.stackexchange.com/questions/133358/do-apple-watch-mathematica-integrations-still-work
I tried to follow this blog post: Instant Apps for Apple Watch, but none of the examples given worked, instead, they would simply hang on the "loading" screen.
Can anyone verify if this ...
- asked by M.R. (9 votes)
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[Locate Start and End Positions of Repeated Sequences in a list] http://mathematica.stackexchange.com/questions/133164/locate-start-and-end-positions-of-repeated-sequences-in-a-list
ListA = 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 12, 12, 12, 14, 14, 14, 12, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, 14, ...
- asked by SPIL (8 votes), answered by Suba Thomas (5 votes)
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[How can I add noise to a neural network input?] http://mathematica.stackexchange.com/questions/133090/how-can-i-add-noise-to-a-neural-network-input
A common "trick" in neural network training is to train an autoencoder using a "degraded" sample as input and the original sample as target output. The layer type DropoutLayer[] is made for this ...
- asked by nikie (8 votes), answered by nikie (5 votes)
================================== Greatest hits from previous weeks: ==================================
[Can Mathematica do symbolic linear algebra?] http://mathematica.stackexchange.com/questions/3242/can-mathematica-do-symbolic-linear-algebra
For instance, is there some way I can say "let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ...
- asked by nikie (38 votes), answered by helen (19 votes)
—————————-
[Calculate the 2D Fourier transform of an Image] http://mathematica.stackexchange.com/questions/29203/calculate-the-2d-fourier-transform-of-an-image
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase spectrum, as well as reconstruct the ...
- asked by user8727 (5 votes), answered by Nasser (27 votes)
================================== Can you answer these? ==================================
[Mathematica script, called from Windows task scheduler, does not export graphics] http://mathematica.stackexchange.com/questions/133075/mathematica-script-called-from-windows-task-scheduler-does-not-export-graphics
When I run the following script from command line,
Needs["JLink`"]; ConnectToFrontEnd[]; resultChart = UseFrontEnd[JuliaSetPlot[0.365 - 0.37 I]]; UseFrontEnd[Export["test.png", resultChart]];
...
- asked by Karsten W. (2 votes)
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[Is it possible to do matrix algebra symbolically?] http://mathematica.stackexchange.com/questions/132955/is-it-possible-to-do-matrix-algebra-symbolically
I’m reading a book that has the following theorem:
I am trying to make Mathematica perform these calculations for me. Is it possible to do it without having to declare the matrices? For ...
- asked by Oppa Hilbert Style (2 votes)
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[Making graphic objects disappear interactively] http://mathematica.stackexchange.com/questions/133256/making-graphic-objects-disappear-interactively
I am trying to create a program where dots on a plane disappear when an object passes over them. I am using EventHandler to code the arrow keys for control of the object. I want each dot to ...
- asked by Savannah S (1 vote)
================================== Top new questions this week: ==================================
[How to find arXiv articles] http://mathematica.stackexchange.com/questions/132685/how-to-find-arxiv-articles
I found at Twitter that is possible to search for arXiv articles with Mathematica:
E.g. the following code:
arXiv = ServiceConnect["ArXiv"]; articles = arXiv["Search", {"Query" -> ...
- asked by mrz (16 votes), answered by user21 (11 votes)
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[Find lane lines] http://mathematica.stackexchange.com/questions/132443/find-lane-lines
A crucial step in self-driving car is to detect lane lines. I’m wondering whether this can be achieved robustly using Mathematica’s rich image processing tools.
For example how can I take camera ...
- asked by xslittlegrass (14 votes), answered by nikie (14 votes)
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[Neural Network for polynomial fit] http://mathematica.stackexchange.com/questions/132546/neural-network-for-polynomial-fit
I’m trying to build up a neural network with Mathematica 11.0, that should fit data which behaves like a polynom of third order. I thought that an NN with one or two hidden layers can fit any ...
- asked by A.Zachl (12 votes), answered by nikie (9 votes)
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[How to make notebooks suitable for the Documentation Center?] http://mathematica.stackexchange.com/questions/132392/how-to-make-notebooks-suitable-for-the-documentation-center
Normally, documentation meant to be integrated into the Documentation Center is built from special source notebooks.
According to the Workbench documentation, it should also be possible to use ...
- asked by Szabolcs (12 votes), answered by jkuczm (5 votes)
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[Largest palindrome from given string] http://mathematica.stackexchange.com/questions/132834/largest-palindrome-from-given-string
Someone recently posted a request on LinkedIn for an algorithm to find the largest palindrome from a given string.
I came up with this, which I believe does the trick, but I am wondering if there ...
- asked by Jonathan Kinlay (10 votes), answered by Kuba (10 votes)
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[Why Function is not identical to `&`
in autocompilation?]
http://mathematica.stackexchange.com/questions/132656/why-function-is-not-identical-to-in-autocompilation
Here is the example, copied from here
square = Function[x, x^2]; square1 = #^2 &;
the timing and unpacking status shows
data = RandomReal[0, 10, 10000];
...
- asked by matheorem (10 votes), answered by m_goldberg (4 votes)
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[Analytic solution to Newtonian gravity differential equation] http://mathematica.stackexchange.com/questions/132875/analytic-solution-to-newtonian-gravity-differential-equation
I was told that I could obtain an analytic solution to a particle falling under the influence of Newtonian gravity by using DSolveValue.
What I am given
\(G = M = m = 1\) \(M\) is a point mass at \(z=0\) ...
- asked by Joe (9 votes), answered by Kagaratsch (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Unit Discovery: Is this some sort of a sick joke?] http://mathematica.stackexchange.com/questions/124745/unit-discovery-is-this-some-sort-of-a-sick-joke
Alright, let’s have some fun here. I am essentially following the documentation by Wolfram, just looking at different quantities.
N[UnitConvert[Quantity["earth's gravity"]]] 9.80665m/(s)^2
Hmm, ...
- asked by Pirx (30 votes), answered by xavier (30 votes)
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[How can Mathematica be used to create images like these?] http://mathematica.stackexchange.com/questions/118992/how-can-mathematica-be-used-to-create-images-like-these
Here are two examples of artistic image interpolation using just black lines:
TRIANGULATION: ANGULAR CELEBRITIES DRAWN WITH A PEN Interpolation for Triangulation-represented Digital Image
The ...
- asked by R Hall (28 votes), answered by MarcoB (29 votes)
================================== Can you answer these? ==================================
[How to find a value to make function positive and real?] http://mathematica.stackexchange.com/questions/132883/how-to-find-a-value-to-make-function-positive-and-real
Let
x=(((-3 + r) r^2 + a^2 (1 + r)) Csc[])/(a (-1 + r)) y=Sqrt[(a^2 (a^2 (1 + r)^2 + 2 r^2 (-3 + r^2)) + a^4 (-1 + r)^2 Cos[]^2 - ((-3 + r) r^2 + a^2 (1 + r))^2 Csc[]^2)/(a^2 (-1 + r)^2)]
...
- asked by MrDi (1 vote)
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[Creating an automatic code feedback for class] http://mathematica.stackexchange.com/questions/132880/creating-an-automatic-code-feedback-for-class
I’m trying to create a server application that accepts uploaded Mathematica files (that follow a certain API), then run a few tests on modules defined within those files. This is for a course where ...
- asked by michael99man (1 vote)
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[Nontrivial background removal] http://mathematica.stackexchange.com/questions/132844/nontrivial-background-removal
I have an image of a product on a poorly made green screen and need to segment out just the product:
The problem is that it contains a mirror, so simple color-based methods are not enough.
I tried ...
- asked by M.R. (4 votes)
================================== Top new questions this week: ==================================
[PacletInfo.m documentation project] http://mathematica.stackexchange.com/questions/132064/pacletinfo-m-documentation-project
Packages can be made into paclets, which provides easy distribution and versioning. The paclet metadata is in the PacletInfo.m file. The PacletInfo settings also determine how the paclet can extend ...
- asked by Szabolcs (25 votes), answered by Szabolcs (22 votes)
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[Replace custom functions, leave built in functions untouched?] http://mathematica.stackexchange.com/questions/131938/replace-custom-functions-leave-built-in-functions-untouched
I have three expressions a[x, y], b[x, y], c[x, y] that act as placeholders for functions of two variables x,y. Consider the following substitution: a[x, y]/(b[x, y] c[x, y]) /. f_[x1_, y1_] :> ...
- asked by Kagaratsch (16 votes), answered by Mr.Wizard (18 votes)
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[Why CompilationTarget -> C is slower than directly writing with C?] http://mathematica.stackexchange.com/questions/132130/why-compilationtarget-c-is-slower-than-directly-writing-with-c
Probably a hard question, but I think it’s better to cry out loud.
I’ve hesitated for a while about whether I should post this in StackOverflow with a c tag or not, but finally decide to keep it ...
- asked by xzczd (15 votes), answered by Albert Retey (11 votes)
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[Detecting kernel initialization] http://mathematica.stackexchange.com/questions/132212/detecting-kernel-initialization
Certain operations do not work during kernel initialization. Code from Kernel/init.m, the Autoload directory, or packages set to autoload may evaluate at initialization time.
Is there a way to ...
- asked by Szabolcs (12 votes), answered by Szabolcs (10 votes)
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[How can I change the default file type for "Save Selection As"] http://mathematica.stackexchange.com/questions/132224/how-can-i-change-the-default-file-type-for-save-selection-as
When using the menu item File - Save Selection As, the default file type is PDF. Is there any way to change the default to something else, for example PNG?
- asked by Simon Woods (12 votes), answered by Mike Honeychurch (13 votes)
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[How to obtain the ViewPoint] http://mathematica.stackexchange.com/questions/132228/how-to-obtain-the-viewpoint
Normally, I used ViewPoint in the code in Plot3D. Most of the time, I will use mouse to rotate the 3D object to get a better view point. The problem is, when I find the best view point for me, is ...
- asked by Qi Zhong (12 votes), answered by Jack LaVigne (14 votes)
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[Wonky Solutions to Schrödinger Equation with Box Barrier] http://mathematica.stackexchange.com/questions/131854/wonky-solutions-to-schr%C3%B6dinger-equation-with-box-barrier
I’m trying to solve the Schrödinger equation using NDSolve in a case where there is a potential box barrier. The initial condition is a cosine wave, and for boundary conditions I require that the ...
- asked by Buddhapus (8 votes), answered by xzczd (4 votes)
================================== Greatest hits from previous weeks: ==================================
[Can Mathematica do symbolic linear algebra?] http://mathematica.stackexchange.com/questions/3242/can-mathematica-do-symbolic-linear-algebra
For instance, is there some way I can say "let A and B be arbitrary real \(m\times n\) and \(k\times m\) matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ...
- asked by nikie (35 votes), answered by helen (18 votes)
—————————-
[How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc] http://mathematica.stackexchange.com/questions/66273/how-to-tell-mathematica-that-certain-variables-are-real-imaginary-integer-value
I’m trying to expedite some quantum mechanical calculations by running them through Mathematica. Expectation values and stuff like that. When I say, for example,
u[x_] := Sqrt[2/L] * Sin[Pi * n * x / ...
- asked by Matthew Brunetti (9 votes), answered by SquareOne (7 votes)
================================== Can you answer these? ==================================
[Is it possible to change the text cursor’s shape and color?] http://mathematica.stackexchange.com/questions/132322/is-it-possible-to-change-the-text-cursors-shape-and-color
I find it visually pleasant to reverse the background and foreground colors when working on a notebook; as shown below, in fact, it’s almost a requirement after working long hours on the same ...
- asked by Jerome Ibanes (1 vote)
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[FindClusters doesn’t accept custom DistanceFunction] http://mathematica.stackexchange.com/questions/132287/findclusters-doesnt-accept-custom-distancefunction
I have a problem with using custom DistanceFunction in FindClusters. To make the issue as simple as possible, consider clustering odd & even numbers in the following way:
...
- asked by ahrvoje (6 votes)
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[FrameLabel is Broken for ArrayPlot and MatrixPlot] http://mathematica.stackexchange.com/questions/132008/framelabel-is-broken-for-arrayplot-and-matrixplot
In version 11.0.1 the documentation for FrameLabel states its format is
left, right, bottom, top
However, it appears that this is not the case for MatrixPlot.
...
- asked by Edmund (5 votes)
================================== Top new questions this week: ==================================
[Create the source image for this cool animated illusion] http://mathematica.stackexchange.com/questions/131644/create-the-source-image-for-this-cool-animated-illusion
Have a look at this very awesome video:
https://www.youtube.com/watch?v=lvvcRdwNhGM
You have a vertically discretized image, which is composed of 5 or 6 images, which are shifted by an increment, as ...
- asked by DoHe (22 votes), answered by corey979 (25 votes)
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[Restarting Mathematica automatically] http://mathematica.stackexchange.com/questions/131573/restarting-mathematica-automatically
I run a large computation in a loop. At each cycle of the loop I produce large arrays that I save on a disk. At each cycle I would like to Quit Mathematica and then restart automatically, loading ...
- asked by Vadim (15 votes), answered by Szabolcs (14 votes)
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[How to handle package dependencies?] http://mathematica.stackexchange.com/questions/131567/how-to-handle-package-dependencies
When an application written in C++ depends on some libraries, the libraries are usually shipped together with the application. Two applications that depend on the same library will not share the same ...
- asked by Szabolcs (11 votes), answered by Kuba (3 votes)
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[How to sample many points below a curve?] http://mathematica.stackexchange.com/questions/131755/how-to-sample-many-points-below-a-curve
I have plotted the curve, and I wanted to take 1000 points in the shaded area uniformly. How can I make it?
Plot[1/ Cos[]^2, {, 0, 2 }, Filling -> Bottom]
- asked by ZHANG Juenjie (10 votes), answered by bbgodfrey (11 votes)
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[how to style multi-value interpolation function plot?] http://mathematica.stackexchange.com/questions/131516/how-to-style-multi-value-interpolation-function-plot
Is there a cleaner way to apply different styles to the different channels of a multi value interpolation function?
here is a 2-output interpolation function:
f = Interpolation[Table[ {x, N@{Sin[x], ...
- asked by george2079 (10 votes), answered by Michael E2 (7 votes)
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[Backtesting a Probability of Default (PD) model] http://mathematica.stackexchange.com/questions/131347/backtesting-a-probability-of-default-pd-model
Background
PD models
Financial institutions use Probability of Default (PD) models for various purposes such as client acceptance, provisioning and regulatory capital calculation as required by the ...
- asked by Sjoerd C. de Vries (10 votes), answered by Sjoerd C. de Vries (14 votes)
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[Display bug in Dataset’s UnitConvert handling] http://mathematica.stackexchange.com/questions/131332/display-bug-in-datasets-unitconvert-handling
Bug introduced in 11.0.1 (or possibly 11.0.0)
Is this yet another annoying regression in v11 Dataset type handling? The display form seems to be a formatting bug:
The numerator and denominator of ...
- asked by alancalvitti (10 votes), answered by WReach (4 votes)
================================== Greatest hits from previous weeks: ==================================
[Exporting graphics to PDF - huge file] http://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[\[Theta]], r Sin[\[Theta]], ...
- asked by Matthew Leingang (85 votes), answered by Heike (74 votes)
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[How to create a new "person curve"?] http://mathematica.stackexchange.com/questions/17704/how-to-create-a-new-person-curve
Wolfram|Alpha has a whole collectionź of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica notebook, or person curve into ...
- asked by Simon (61 votes), answered by Vitaliy Kaurov (30 votes)
================================== Can you answer these? ==================================
[Unix-like reference to parent and root Association?] http://mathematica.stackexchange.com/questions/131337/unix-like-reference-to-parent-and-root-association
Is there a syntax or function to reference parent and root when querying nested Associations similar to Unix' ".." and "/", eg "cd ../../mydir". ?
Here’s a typical application of the root ...
- asked by alancalvitti (3 votes)
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[Strange behaviour of FullSimplify when checking an equality of SparseArray’s] http://mathematica.stackexchange.com/questions/131400/strange-behaviour-of-fullsimplify-when-checking-an-equality-of-sparsearrays
I stumbled upon the following strange behaviour. Disclaimer: I present the simplest instance that I could find in which some behaviour occurs that I first noticed in a different, more complicated ...
- asked by Jules Lamers (1 vote)
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[ListPlot PlotRange Ignored with all Missing or empty data] http://mathematica.stackexchange.com/questions/131321/listplot-plotrange-ignored-with-all-missing-or-empty-data
I have a function that uses ListPlot to draw a custom plot. When a data value is not applicable I pass in Missing to prevent ListPlot and its Prolog option from displaying the point the function will ...
- asked by Edmund (3 votes)
================================== Top new questions this week: ==================================
[Why (and when) does pattern matching with f[__]
perform MUCH more quickly than _f?]
http://mathematica.stackexchange.com/questions/130984/why-and-when-does-pattern-matching-with-f-perform-much-more-quickly-than
Consider this expression in Mathematica 10.3 (and above) on MacOS X:
expr = a b c d e f g h i j k l m n o p q r s t myG[u] myF[a, b]
Now compare the time it takes to apply the following ...
- asked by QuantumDot (22 votes), answered by WReach (17 votes)
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[Getting wrong limit with Bessel] http://mathematica.stackexchange.com/questions/130741/getting-wrong-limit-with-bessel
I computed a following limit (related to the asymptotic expansion of the sequence A000009 - number of partitions of n into distinct parts)
Expand[Limit[((( BesselI[1, (Sqrt[1/24 + n] ...
- asked by Vaclav Kotesovec (11 votes), answered by Akku14 (9 votes)
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[Join lists by observing x-value] http://mathematica.stackexchange.com/questions/130903/join-lists-by-observing-x-value
Hi everybody I have as a small test with two datasets (normally I have 100 datasets with 4100 brackets):
Dataset1={{20,1},{30, 1.3}, {40, 0.4}, {50, 0.9}} Dataset2={{30, 1.2}, {40, 1}, {50, 0.4}, ...
- asked by Jacccy (10 votes), answered by ubpdqn (13 votes)
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[How to distribute Mathematica packages as paclets?] http://mathematica.stackexchange.com/questions/131101/how-to-distribute-mathematica-packages-as-paclets
Mathematica does have a nice package manager. Packages are called paclets, and they can be managed using the functions from the PacletManager‘ context.
How can I package up my own packages as ...
- asked by Szabolcs (9 votes), answered by Szabolcs (7 votes)
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[Does function call via @ ignore HoldFirst attribute?] http://mathematica.stackexchange.com/questions/130889/does-function-call-via-ignore-holdfirst-attribute
I was trying to test whether using func[x,y] is the same as func[#,y]&@x:
SetAttributes[test, HoldFirst] test[1 + 2 - 3, 5 - 5] test[#, 5 - 5] &@(1 + 2 - 3) test[1 + 2 - 3, 0]
...
- asked by Ruslan (8 votes), answered by m_goldberg (9 votes)
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[Graph visualization: Leave gap between vertex and endpoint of edge] http://mathematica.stackexchange.com/questions/130821/graph-visualization-leave-gap-between-vertex-and-endpoint-of-edge
This is a nice graph:
g = CycleGraph[4]; Graph[g, VertexCoordinates -> {{0, 0}, {0, 1}, {1, 1}, {1, 0}}, VertexLabels -> Placed["Name", Center], VertexSize -> Medium, EdgeShapeFunction ...
- asked by cyrille.piatecki (8 votes), answered by kglr (12 votes)
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[Help finding the centre of a faint, incomplete circle?] http://mathematica.stackexchange.com/questions/130787/help-finding-the-centre-of-a-faint-incomplete-circle
so I found a program in the answers to this question that I thought was brilliant, so here it is applied to my situation: I have the image
and here’s the code:
...
- asked by Mason (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How can Mathematica be used to create images like these?] http://mathematica.stackexchange.com/questions/118992/how-can-mathematica-be-used-to-create-images-like-these
Here are two examples of artistic image interpolation using just black lines:
TRIANGULATION: ANGULAR CELEBRITIES DRAWN WITH A PEN Interpolation for Triangulation-represented Digital Image
The ...
- asked by R Hall (28 votes), answered by MarcoB (29 votes)
—————————-
[How do you make a Neural Net?] http://mathematica.stackexchange.com/questions/123458/how-do-you-make-a-neural-net
In the new Mathematica release (v11), NeuralNetworks is one of the new main features. However, the documentation isn’t that clear on what function should be used in a Net.
The documentation on ...
- asked by JHM (22 votes), answered by Searke (24 votes)
================================== Can you answer these? ==================================
[Understanding the structure of an InterpolatingFunction] http://mathematica.stackexchange.com/questions/131063/understanding-the-structure-of-an-interpolatingfunction
FunctionInterpolation[x^2, {x, 0, 9}] // InputForm
returns:
InterpolatingFunction[ 0., 9., 5, 3, 0, 13, 4, 0, 0, 0, 0, Automatic, , , False, 0., 0.75, 1.5, 2.25, 3., 3.75, ...
- asked by anderstood (1 vote)
—————————-
[Is it possible to create .stp 3D model from Graphics3D?] http://mathematica.stackexchange.com/questions/130883/is-it-possible-to-create-stp-3d-model-from-graphics3d
I want to create some 3D solid model by Mathematica, and then export it into stp (step) format for further finite element or finite volume analysis in Fluent/ANSYS or Abaqus.
But so far to me, it ...
- asked by user6043040 (3 votes)
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[Time constrained loop unit] http://mathematica.stackexchange.com/questions/131159/time-constrained-loop-unit
I have a particularly difficult loop, in that it consists of two variables looping and sowing the result if a criteria is met. Overall it works for me, but some certain values for my variables take ...
- asked by Castle (2 votes)
================================== Top new questions this week: ==================================
[For a better animation of the solution from NDSolve] http://mathematica.stackexchange.com/questions/130502/for-a-better-animation-of-the-solution-from-ndsolve
I obtained a numerical solution from the following code with NDSolve
L = 20; tmax = 27; \[Sigma] = 2; myfun = First[h /. NDSolve[{D[h[x, y, t], t] + Div[h[x, y, t]^3*Grad[Laplacian[h[x, y, t], {x, ...
- asked by jsxs (12 votes), answered by Nasser (14 votes)
—————————-
[A puzzling result of "FullSimplify"] http://mathematica.stackexchange.com/questions/130606/a-puzzling-result-of-fullsimplify
When I input:
FullSimplify[(1 - a^2)/b^2, a^2 + b^2 == 1]
the result is the ideal answer 1
Howeverif I input:
FullSimplify[(1 - b^2)/a^2, a^2 + b^2 == 1] the result is (1 - b^2)/a^2 ...
- asked by dabuyang (11 votes), answered by Bob Hanlon (7 votes)
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[ImageFeatureTrack or ImageDisplacements to measure average object velocities in images] http://mathematica.stackexchange.com/questions/130391/imagefeaturetrack-or-imagedisplacements-to-measure-average-object-velocities-in
I have as example a set of 30 gray scale images (8bit, 568*478 pixels, they are avalable here: http://tinyurl.com/zckyv9w where bright objects on dark background move from image to image mainly ...
- asked by mrz (9 votes), answered by Simon Woods (10 votes)
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[Documentation Tools: Don’t put web URL in user package docs] http://mathematica.stackexchange.com/questions/130515/documentation-tools-dont-put-web-url-in-user-package-docs
I am exploring the Workbench documentation tools for the first time and one of the difficulties I encountered was that every generated (compiled) documentation page includes weblinks. These point to ...
- asked by Szabolcs (9 votes)
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[How to make plots ’blacker’?] http://mathematica.stackexchange.com/questions/130471/how-to-make-plots-blacker
I need to make a contour plot for publication, but even if I set ContourStyle->Black, the 'black' plots and the axes are very faint. When I export the figure in svg and open it in some ...
- asked by Physicist (9 votes), answered by Michael E2 (10 votes)
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[How to specify algebraic relations between objects?] http://mathematica.stackexchange.com/questions/130258/how-to-specify-algebraic-relations-between-objects
so I’m wanting to screw around a bit with Geometric Algebra in Mathematica. To start, I want to create some basis objects: \(e_1,~ e_2,~e_3\) and then specify the relations between them which are
- asked by Mason (9 votes), answered by march (9 votes)
—————————-
[Crack it If you Can? BUT in the BEST way] http://mathematica.stackexchange.com/questions/130566/crack-it-if-you-can-but-in-the-best-way
From the Wolfram Community:
Hello everyone,
A little while ago I was asked to solve this "safe cracker" puzzle, a sweet example of a coffee table puzzle. The basic gist of this puzzle is that it ...
- asked by Youphyso (8 votes), answered by george2079 (4 votes)
================================== Greatest hits from previous weeks: ==================================
[Writing a word with straight lines] http://mathematica.stackexchange.com/questions/113403/writing-a-word-with-straight-lines
Here is an interesting way to write a word: (it is from a poster for the International Museum Day 2006; I believe it even won an award at an international design competition)
by Boris Ljubicic. ...
- asked by VividD (72 votes), answered by Anton Antonov (34 votes)
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[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (441 votes), answered by faysou (396 votes)
================================== Can you answer these? ==================================
[Passing boolean parameters to a .NET Method using NETLink] http://mathematica.stackexchange.com/questions/130658/passing-boolean-parameters-to-a-net-method-using-netlink
According to the NETLink documentation, NETLink automatically handles type conversions from Mathematica to a .NET dll. One of the issues I have is that the .NET method I want to use expects a Boolean ...
- asked by user39464 (1 vote)
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[ParametricPlot3D Self Intersection] http://mathematica.stackexchange.com/questions/130460/parametricplot3d-self-intersection
I would like to know where my ParametricPlot3D intersects itself and to extract all intersections (points, lines, surfaces...) to animate them by changing P:
ParametricPlot3D[{fX[u,v,P], fY[u,v,P], ...
- asked by chkone (3 votes)
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[Faster solution to combinatorial problem of two-part contractions] http://mathematica.stackexchange.com/questions/130598/faster-solution-to-combinatorial-problem-of-two-part-contractions
Given a list of elements I need all possible pairings of elements with a leading factor that describes the number of permutations. A (ugly but) working version would be:
list = {a, b, c, d}; res = ...
- asked by pbx (2 votes)
================================== Top new questions this week: ==================================
[Huge bug involving MultinormalDistribution?] http://mathematica.stackexchange.com/questions/129916/huge-bug-involving-multinormaldistribution
Bug introduced in 8.0 or earlier and persisting through 11.0.1
I found a strange behavior regarding the CDF of the bivariate Normal distribution
...
- asked by fwgb (21 votes), answered by Eric Towers (19 votes)
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[GeoDistance - higher spatial resolution / precision?] http://mathematica.stackexchange.com/questions/130044/geodistance-higher-spatial-resolution-precision
I’m having a small problem with GeoDistance.
I’ve chosen a target city – San Francisco – and I’ve computed distances from SF to five other cities. Then I draw circles around each city, with radius ...
- asked by ConvexMartian (9 votes), answered by jose (4 votes)
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[How to extract the first dimension in TimeSeries?] http://mathematica.stackexchange.com/questions/129836/how-to-extract-the-first-dimension-in-timeseries
I want to extract the first dimension in TimeSeriesfor example:
So I use this code:
data = Normal@AudioLocalMeasurements[ExampleData[{"Audio", "PianoScale"}],"MFCC"]; Thread[{data[[All, 1]], ...
- asked by partida (9 votes), answered by kglr (6 votes)
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[How to recover Pauli matrices properties in Mathematica?] http://mathematica.stackexchange.com/questions/129799/how-to-recover-pauli-matrices-properties-in-mathematica
I want to do a cross or dot product involving a vector of Pauli matrices =(1,2,3); for example, x=2i or .=3I.
Is there a simple way to do these operations?
- asked by user3654016 (8 votes), answered by corey979 (10 votes)
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[Flatten sublists within a bigger list] http://mathematica.stackexchange.com/questions/130011/flatten-sublists-within-a-bigger-list
Really sorry if this question is a duplicate. I couldn’t find exactly what I was looking for.
Here is a list I have:
{{{0. + 0.1875 I, 0. + 0.105469 I, 0. + 0.03125 I, 0. + 0.00390625 I, 0. + ...
- asked by jrekier (7 votes), answered by Edmund (6 votes)
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[7-dimensional cross product] http://mathematica.stackexchange.com/questions/129863/7-dimensional-cross-product
How to define a 7-dimensional cross product?
$$\begin{aligned}\mathbf {x} \times \mathbf {y} =(x_{2}y_{4}-x_{4}y_{2}+x_{3}y_{7}-x_{7}y_{3}+x_{5}y_{6}-x_{6}y_{5})\,&\mathbf {e} ...
- asked by corey979 (7 votes), answered by Sumit (4 votes)
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[How to draw a clock-diagram?] http://mathematica.stackexchange.com/questions/129960/how-to-draw-a-clock-diagram
I found a clock-diagram in a paper, so I would like to draw it in Mathematica. The main trouble for me is the corresponding line segments on the circle.
I would let the data1 lie the outside on the ...
- asked by user123 (7 votes), answered by Feyre (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How can Mathematica be used to create images like these?] http://mathematica.stackexchange.com/questions/118992/how-can-mathematica-be-used-to-create-images-like-these
Here are two examples of artistic image interpolation using just black lines:
TRIANGULATION: ANGULAR CELEBRITIES DRAWN WITH A PEN Interpolation for Triangulation-represented Digital Image
The ...
- asked by R Hall (28 votes), answered by MarcoB (29 votes)
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[How to tell Mathematica that certain variables are real/imaginary, integer-valued, etc] http://mathematica.stackexchange.com/questions/66273/how-to-tell-mathematica-that-certain-variables-are-real-imaginary-integer-value
I’m trying to expedite some quantum mechanical calculations by running them through Mathematica. Expectation values and stuff like that. When I say, for example,
u[x_] := Sqrt[2/L] * Sin[Pi * n * x / ...
- asked by Matthew Brunetti (8 votes), answered by SquareOne (6 votes)
================================== Can you answer these? ==================================
[How to Inset a legend in GeoGraphics with Scaled LegendMarkerSize?] http://mathematica.stackexchange.com/questions/130060/how-to-inset-a-legend-in-geographics-with-scaled-legendmarkersize
I have a GeoGraphics where I am using Scaled in PointSize to include size information. I want to Inset a PointLegend that describes the sizes of the points.
Outside of GeoGraphics I can do this by ...
- asked by Edmund (2 votes)
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[NumberLinePlot with Exponential] http://mathematica.stackexchange.com/questions/129938/numberlineplot-with-exponential
I have:
Clear[f, x] f[x_] = Exp[1/x] Now, the question is "where is the derivative negative?" I managed to get the Reduce command to work by adding Reals. Reduce[f'[x] < 0, x, Reals]
Which ...
- asked by David (3 votes)
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[Detect numbers on the image] http://mathematica.stackexchange.com/questions/129821/detect-numbers-on-the-image
How to detect numbers on the following image
I tried:
img=Import["http://imgur.com/TDbn7sB.png"] set = ImagePartition[img, Scaled[{1/20, 1/5}]] // Flatten
then I tried Classify[] but it ...
- asked by vito (3 votes)
================================== Top new questions this week: ==================================
[How to improve this plot?] http://mathematica.stackexchange.com/questions/129426/how-to-improve-this-plot
In general, the quality of Mathematica graphics is beyond praise. However, the output of Plot3D command is somewhat unexpected in the following code. Let’s solve the Dirichlet problem for the ...
- asked by user64494 (11 votes), answered by Simon Woods (16 votes)
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[Neural Networks: Does Mathematica (v11) experimental code support state-of-art Models?] http://mathematica.stackexchange.com/questions/129469/neural-networks-does-mathematica-v11-experimental-code-support-state-of-art-m
Mathematica made a big step implementing Neural Networks. I checked some examples for deep learning (ChainNet), also the related link. I see that model structures such as LaNet can be developed. ...
- asked by s.s.o (10 votes), answered by Alexey Golyshev (8 votes)
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[Converting Game of Life images to lists] http://mathematica.stackexchange.com/questions/129135/converting-game-of-life-images-to-lists
I want to convert images of GoL configurations into binary matrices to run in Mathematica’s CellularAutomaton. I know that there’s a collection of GoL patterns in http://conwaylife.com and other ...
- asked by andandandand (10 votes), answered by C. E. (5 votes)
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[JDBC-to-ODBC bridge gone. How to connect to SQL Server now in case of Windows Authentication?] http://mathematica.stackexchange.com/questions/129160/jdbc-to-odbc-bridge-gone-how-to-connect-to-sql-server-now-in-case-of-windows-au
Connecting to our corporate SQL servers using JDBC never worked for me, perhaps related to the Windows Authentication method that is necessary in our network. However, I found out that configuring the ...
- asked by Sjoerd C. de Vries (8 votes), answered by Sjoerd C. de Vries (6 votes)
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[How to speed up calculations on big symbolic matrices?] http://mathematica.stackexchange.com/questions/129465/how-to-speed-up-calculations-on-big-symbolic-matrices
this is my first time posting something on a community of the StackExchange platform, so please feel free to correct me if I’m doing something wrong. :) Additionally you should probably know that I’m ...
- asked by TSwift (8 votes)
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[How do I ’Join’ two Structured Datasets?] http://mathematica.stackexchange.com/questions/129116/how-do-i-join-two-structured-datasets
Consider the following Datasets
dsCompetitions with fields "id","name","eventTypeId"
dsEventTypes with fields "id", "name"
I want to join the datasets as follows using SQL pseudocode:
SELECT ...
- asked by nilo de roock (8 votes), answered by rcollyer (7 votes)
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[Why isn’t Orderless an Attribute of And?] http://mathematica.stackexchange.com/questions/129415/why-isnt-orderless-an-attribute-of-and
In standard logic And is a commutative operator. Still, in Mathematica, And doesn’t have the Orderless attribute:
Attributes[And] (* {Flat,HoldAll,OneIdentity,Protected} *)
This may have not been ...
- asked by Soldalma (7 votes), answered by JHM (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Programming the fiver game] http://mathematica.stackexchange.com/questions/120959/programming-the-fiver-game
Obviously, even if I ask a lot of question I am, obviously, still a dummy!!!!
I want to program the fiver game. It’s a very simple game played solitary on a \(5 \times 5\) the rule is elementary : if ...
- asked by cyrille.piatecki (12 votes), answered by Mr.Wizard (19 votes)
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[How to make an inkblot?] http://mathematica.stackexchange.com/questions/3345/how-to-make-an-inkblot
How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):
RandomBlot[num_, opts___] := ...
- asked by István Zachar (83 votes), answered by Sjoerd C. de Vries (46 votes)
================================== Can you answer these? ==================================
[Counting the occurences of entries in a dataset columnwise] http://mathematica.stackexchange.com/questions/129459/counting-the-occurences-of-entries-in-a-dataset-columnwise
Consider a dataset with some rows and considerably less columns (eg something like 10x3). Assume that the contents of the dataset cells are integers from some conveniently chosen range (eg 1 through ...
- asked by user42582 (1 vote)
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[List, Association, and Dataset, according to what principles to choose which one to use?] http://mathematica.stackexchange.com/questions/129081/list-association-and-dataset-according-to-what-principles-to-choose-which-one
List, Association and Dataset are three ’objects’ that can be used to store data in MMA. So when or under what conditions for one to decide to use each of them?
- asked by Alexander Zeng (2 votes)
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[How to ArrayFlatten some matrix which have repeated element] http://mathematica.stackexchange.com/questions/129153/how-to-arrayflatten-some-matrix-which-have-repeated-element
I have many such matrices(whose dimension are all 3*3.) like:
list1={{0,3,0},{4,1,2},{0,5,0}}; list2={{0,6,0},{1,2,8},{0,7,0}}; list3={{0,1,0},{9,5,7},{0,11,0}}; list4={{0,2,0},{5,7,10},{0,12,0}};
...
- asked by yode (3 votes)
================================== Top new questions this week: ==================================
[Why removing a function and defining it on the same line does not work?] http://mathematica.stackexchange.com/questions/128818/why-removing-a-function-and-defining-it-on-the-same-line-does-not-work
Why do the two pieces of code below yield rather different results? The only difference is that in the first one the function definition is in the same line as the Remove command while in the second ...
- asked by Fernando Saldanha (17 votes), answered by dan7geo (16 votes)
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[House of Santa Claus] http://mathematica.stackexchange.com/questions/128741/house-of-santa-claus
The house of Santa Claus is an old German drawing game for small children. You have to draw a house in one line. You must not lift your pencil while drawing.
$\color{red}{\text{You must not repeat a ...
- asked by mrz (15 votes), answered by Dr. Wolfgang Hintze (9 votes)
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[how to get cell boundaries in the image] http://mathematica.stackexchange.com/questions/128596/how-to-get-cell-boundaries-in-the-image
I have a microscope image of some animal tissue and wish to get the contours for all the cells that are present in the image. the cells are connected to the neighbouring cells via these contours. At ...
- asked by Ali Hashmi (10 votes), answered by corey979 (13 votes)
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[Numerically solve the initial value problem for the 1-D wave equation] http://mathematica.stackexchange.com/questions/128516/numerically-solve-the-initial-value-problem-for-the-1-d-wave-equation
I want to solve the standard 1-dimensional wave equation \(y_{xx}=y_{tt}\) using NDSolve (for \(y(x,t)\)) with the following conditions:
cond1 = Piecewise[{{1 - Abs[x - 1], Abs[x - 1] < 1}, {0, Abs[x ...
- asked by arcbloom (8 votes), answered by xzczd (7 votes)
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[Dataset Processing: efficient ways to clean and merge sets for Life Sciences] http://mathematica.stackexchange.com/questions/128519/dataset-processing-efficient-ways-to-clean-and-merge-sets-for-life-sciences
Dataset Processing (for Life Sciences)
Note: a related, but distinct task is posted here ID Swapping: Efficient use of a reference table to convert ID values.
A common task, at least for me, ...
- asked by SumNeuron (8 votes), answered by SumNeuron (5 votes)
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[Rotations of a number] http://mathematica.stackexchange.com/questions/128666/rotations-of-a-number
If we start with a number like 1234 and produce the following sum 1234 + 123 + 12 + 1 = 1370.
If we are given the 1370 can I retrieve the 1234? A similar question was migrated over to the Math.SE ...
- asked by bobbym (8 votes), answered by J. M. (6 votes)
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[What’s wrong with the Sum function?] http://mathematica.stackexchange.com/questions/128534/whats-wrong-with-the-sum-function
Here are the codes:
f[n_]:=Sum[1,{K,0,n},{M,0,n-K},{La,0,K},{Lb,0,n-K-M},{Lc,0,M}]//Simplify g[n_]:=Sum[1,{La,0,n},{Lb,0,n-La},{Lc,0,n-La-Lb},{K,La,n-Lb},{M,Lc,n-K-Lb}]//Simplify f[x]/.x->5
...
- asked by lamberto (7 votes), answered by Bob Hanlon (3 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating legends for plots with multiple lines?] http://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines
So I have a graph with multiple lists, for e.g.
data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have no way to generate a legend ...
- asked by Eiyrioü von Kauyf (59 votes), answered by Jens (88 votes)
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[Exporting graphics to PDF - huge file] http://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[\[Theta]], r Sin[\[Theta]], ...
- asked by Matthew Leingang (85 votes), answered by Heike (74 votes)
================================== Can you answer these? ==================================
[Parallelizing code, any tips?] http://mathematica.stackexchange.com/questions/128905/parallelizing-code-any-tips
I have access to a Linux cluster and I’m trying to use Parallelize to run the above bellow faster, but whenever I try to place Parallelize in any other parts, besides the loop, where I think it may ...
- asked by Sergio Parreiras (2 votes)
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[Does Reduce have problems with greek symbols that lead to wrong results?] http://mathematica.stackexchange.com/questions/128965/does-reduce-have-problems-with-greek-symbols-that-lead-to-wrong-results
I call Reduce on the following simple system of inequalities
e = ((-4 + Sqrt[(-2 + )^2] + 3 ) Log[p] + 4 Log[])/(2 ); Reduce[e > 0 && 1 > > 0 && 1 > p > 0 ...
- asked by klm (3 votes)
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[Full screen image in slideshow?] http://mathematica.stackexchange.com/questions/128875/full-screen-image-in-slideshow
Is it possible to make an image fill up and entire slide in a slideshow notebook so that there are no cell brackets or any white space around it at all (when viewed in presentation mode of course)?
- asked by M.R. (1 vote)
================================== Top new questions this week: ==================================
[How to programmatically play an Audio object?] http://mathematica.stackexchange.com/questions/128147/how-to-programmatically-play-an-audio-object
A Sound object can be programmatically played using EmitSound. Example:
snd = ExampleData[{"Sound", "AltoFlute"}]; Button["Play!", EmitSound[snd]]
What about an Audio object?
- asked by Szabolcs (14 votes), answered by Szabolcs (9 votes)
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[TreePlot does not give a "binary-looking" tree for a binary tree] http://mathematica.stackexchange.com/questions/128323/treeplot-does-not-give-a-binary-looking-tree-for-a-binary-tree
I use the following code to generate a binary tree with root 1.
TreePlot[{1 -> 2, 1 -> 3, 2 -> 4, 2 -> 5, 3 -> 6, 3 -> 7, 4 -> 8, 4 -> 9, 5 -> 10, 5 -> 11, 6 -> ...
- asked by Tony (13 votes), answered by WReach (19 votes)
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[Partition array without unpacking] http://mathematica.stackexchange.com/questions/128133/partition-array-without-unpacking
What is the simplest way to partition a list into equal-length sublists, allow the last sublist to be shorter of necessary, and avoid unpacking?
Partition doesn’t usually unpack:
arr = RandomReal[1, ...
- asked by Szabolcs (13 votes), answered by Szabolcs (7 votes)
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[Creating a simple Dock Cell that Fades In when Cursor Hover Over It] http://mathematica.stackexchange.com/questions/128025/creating-a-simple-dock-cell-that-fades-in-when-cursor-hover-over-it
I like to create dock cells, that enhance the look of my notebooks. Do you know of a simple way to get the functionality in iBooks shown below in the video. I want the dock cell in Mathematica to ...
- asked by Michael McCain (13 votes), answered by Karsten 7. (14 votes)
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[Why are Exp[3] and 2 treated differently within Complex?] http://mathematica.stackexchange.com/questions/128211/why-are-exp3-and-2-treated-differently-within-complex
Why doesn’t the last command below split the complex number into its real and imaginary parts?
Complex[2,2] (* 2 + 2 I *) Complex[N[Exp[3]], N[Exp[3]]] (* 20.0855 + 20.0855 I *) ...
- asked by Fernando Saldanha (12 votes), answered by Szabolcs (18 votes)
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[KeyDrop does not respect Key in V11] http://mathematica.stackexchange.com/questions/128171/keydrop-does-not-respect-key-in-v11
KeyDrop[<|a -> 1|>, Key[a]] <|a -> 1|> KeyTake[<|a -> 1|>, Key[a]] <||>
closely related but not the same: Unexpected behavior of KeyTake
Are there any ...
- asked by Kuba (11 votes), answered by Xavier (5 votes)
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[Strategies for creating 3D text] http://mathematica.stackexchange.com/questions/128412/strategies-for-creating-3d-text
I am interested in using Mathematica to create 3D text for printing. I stumbled upon this answer which works very well in a slightly modified form:
text3D[text_String, mult_] := ListPlot3D[ ...
- asked by bobthechemist (10 votes), answered by J. M. (14 votes)
================================== Greatest hits from previous weeks: ==================================
[Is it possible to export the equations from Mathematica to MATLAB?] http://mathematica.stackexchange.com/questions/14035/is-it-possible-to-export-the-equations-from-mathematica-to-matlab
Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?
- asked by Seyhmus Güngören (24 votes), answered by R. M. (32 votes)
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[Labeling individual curves in Mathematica] http://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (47 votes), answered by Artes (37 votes)
================================== Can you answer these? ==================================
[Help: Reclassify] http://mathematica.stackexchange.com/questions/128194/help-reclassify
Is it possible to improve the current ClassifierFunction with more training data without running the previous training again?
In this way i will be able to deal with very large datasets in chunks.
- asked by user13892 (5 votes)
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[Pattern matching problem in version 11.01] http://mathematica.stackexchange.com/questions/128247/pattern-matching-problem-in-version-11-01
Consider this simple example:
p1 = ListPlot3D[ Table[Sin[j^2 + i], {i, 0, Pi, Pi/5}, {j, 0, Pi, Pi/5}], Mesh -> None, Axes -> False, Boxed -> False, ColorFunction -> Hue]; p2 = ...
- asked by xslittlegrass (8 votes)
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[CUDADot runs slowly and writes "CUDALink experienced a kernel launch failure" with matrix size > 3300] http://mathematica.stackexchange.com/questions/128124/cudadot-runs-slowly-and-writes-cudalink-experienced-a-kernel-launch-failure-wi
I am trying to learn CUDA and start from the help examples. It turnes out that CPU calculation is much faster for matrix sizes < 3200 than CUDA, while CUDADot gives the error for sizes > 3300. I ...
- asked by luu (4 votes)
================================== Top new questions this week: ==================================
[UI performance with large image data] http://mathematica.stackexchange.com/questions/127523/ui-performance-with-large-image-data
Some days ago, I built a small program for some of my colleagues to analyse cell images. One minor part of the user interface was the selection of the region of interest. The images are large and need ...
- asked by halirutan (25 votes), answered by Kuba (21 votes)
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[Transform sphere to an ellipse in \(R^2\)] http://mathematica.stackexchange.com/questions/127645/transform-sphere-to-an-ellipse-in-r2
In Lay’s Linear Algebra and Its Applications textbook, he defines the matrix \[A=\begin {bmatrix} 4 & 11 & 14\\8 & 7 & -2 \end {bmatrix}\] and claims that the transformation \(T(x)=A x\) ...
- asked by David (15 votes), answered by yarchik (17 votes)
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[Did Fibonacci slow down?] http://mathematica.stackexchange.com/questions/127876/did-fibonacci-slow-down
For Fibonacci numbers we have a nice formula:
\[ \frac {\left (1+\sqrt {5}\right )^n-\left (1-\sqrt {5}\right )^n}{2^{n} \sqrt {5}} \]
We can implement that in Mathematica:
a[n_]:= ...
- asked by Fred Simons (13 votes), answered by Szabolcs (20 votes)
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[I would like to create a fractal by copying, scaling and rotating the initial element] http://mathematica.stackexchange.com/questions/127458/i-would-like-to-create-a-fractal-by-copying-scaling-and-rotating-the-initial-el
I want to create a fractal, which looks like this:
This is rule 150R, which can be found in NKS, page 439.
However, instead of using a cellular automaton, I want to create this fractal from a ...
- asked by Yuriy S (13 votes), answered by wxffles (13 votes)
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[Mathematica + Pythonika on the Raspberry pi] http://mathematica.stackexchange.com/questions/127802/mathematica-pythonika-on-the-raspberry-pi
Due to the high availability of python code for the rpi, I’m trying to call python functions from Mathematica. I know that pythonika works well on OS X, but I can’t compile it on the Raspberry pi.
...
- asked by elbOlita (12 votes), answered by elbOlita (13 votes)
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[How to map and sum a list fast?] http://mathematica.stackexchange.com/questions/127658/how-to-map-and-sum-a-list-fast
The following takes a lot of memory and is slow:
Timing[Total[Map[#^2 &, Range[1, 100000000]]]]
I suspect this is because it first calculates and stores the whole list of squared numbers and ...
- asked by Yrogirg (12 votes), answered by BlacKow (19 votes)
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[Implementing the BihamMiddletonLevine traffic model as CellularAutomaton] http://mathematica.stackexchange.com/questions/127821/implementing-the-biham-middleton-levine-traffic-model-as-cellularautomaton
In an attempt to understand how to make rules for CellularAutomaton[], I set out to try to implement the BihamMiddletonLevine traffic model.
It is a 2D, k=3 model with a 3x3 neighborhood, so the ...
- asked by HJensen (10 votes), answered by C. E. (5 votes)
================================== Greatest hits from previous weeks: ==================================
[What are the most common pitfalls awaiting new users?] http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by Dr. belisarius (341 votes), answered by Michael E2 (197 votes)
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[How to make this beautiful animation] http://mathematica.stackexchange.com/questions/112700/how-to-make-this-beautiful-animation
How to make an animation of following gif in Mathematica?
Edit: The animation shown above was created by Charlie Deck in processing.
And how to make 3D analog?
I tried first few steps
line = ...
- asked by vito (47 votes), answered by C. E. (50 votes)
================================== Can you answer these? ==================================
[VectorPlot3D broken in Mathematica 11.0.1?] http://mathematica.stackexchange.com/questions/127724/vectorplot3d-broken-in-mathematica-11-0-1
Here is what I get when simply evaluating the example in the documentation:
This is on Win7 x64. I can see some vectors if I do something like
VectorPlot3D[{1, 1, 1}, {x, -1, 1}, {y, -1, 1}, {z, ...
- asked by Pirx (5 votes)
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[Least squares approximation] http://mathematica.stackexchange.com/questions/127806/least-squares-approximation
I have data points which is mydata = 0, 0, 1, 1, 2, 0;
From this data, I need to do the least squares approximation by using Bernstein polynomials to produce a set of Bezier points. Before ...
- asked by NKamaru (2 votes)
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[Matching key-value pair without converting to List in KeyValueMap] http://mathematica.stackexchange.com/questions/127860/matching-key-value-pair-without-converting-to-list-in-keyvaluemap
I frequently use this method with KeyValueMap in order to match and refer to named parts (ie, "myKey", "myValue")
EDIT: to refer to named parts in the function f without an external function ...
- asked by alancalvitti (1 vote)
================================== Top new questions this week: ==================================
[Should I always be using Module in functions unless I explicitly want global variables?] http://mathematica.stackexchange.com/questions/126877/should-i-always-be-using-module-in-functions-unless-i-explicitly-want-global-var
I define functions a ton. In the past, I’ve mostly just defined my functions like:
myFunc[var1_]:=( var2=var1^2; Return@var2; )
And I haven’t run into too much trouble. If I wanted to be really ...
- asked by YungHummmma (15 votes), answered by WReach (18 votes)
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[Why this real integral yields imaginary results?] http://mathematica.stackexchange.com/questions/127301/why-this-real-integral-yields-imaginary-results
Integrate[(y - y^2 + x - x^2 + 2*x*y)/(1 - x - y),{x,0,1},{y, 0, 1}]
The above integral yields -1-4I/3
in Mathematica. Since the integrand is real (although
divergent at some points), how does ...
- asked by Chong Wang (12 votes), answered by bbgodfrey (12 votes)
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[Would it be a good idea to use Failure and FailureQ in own code] http://mathematica.stackexchange.com/questions/126908/would-it-be-a-good-idea-to-use-failure-and-failureq-in-own-code
Since version 10 (at least 10.0.2 but I think 10.0.0) there is Failure and since version 10.2 there is also FailureQ. As often the documentation is somewhat vague and says "Failure is generated by ...
- asked by Albert Retey (12 votes), answered by Leonid Shifrin (9 votes)
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[Display grayscale image as 3d plot] http://mathematica.stackexchange.com/questions/127210/display-grayscale-image-as-3d-plot
How to build 3d plot of grayscale image where x,y - pixel coordinates, z - pixel intensity?
I tried ListPlot3D[ImageData[image]], but ImageData gives just intensities. I suppose a possible solution ...
- asked by red1ynx (10 votes), answered by Kuba (11 votes)
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[Automatically draw ellipsoids around groups of select points] http://mathematica.stackexchange.com/questions/126899/automatically-draw-ellipsoids-around-groups-of-select-points
Suppose you have a ListPlot, and there are certain points you wish to emphasize belong to particular group. I would like to make a function that automatically draws an ellipsoid around a select group ...
- asked by SumNeuron (10 votes), answered by Szabolcs (11 votes)
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[Enter colors directly into notebook?] http://mathematica.stackexchange.com/questions/127245/enter-colors-directly-into-notebook
In Mathematica notebook interface, you can evaluate:
In[1]:= Black
and you get a colored squared representing the color. Then I can copy and paste this color square and use it as input, like so:
...
- asked by becko (9 votes), answered by WReach (10 votes)
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[Large Dataset query fails if column contains Missing] http://mathematica.stackexchange.com/questions/126851/large-dataset-query-fails-if-column-contains-missing
In version 11.0 (Win 8.1 Pro) a query on a large Dataset for a column that contains Missing fails most unceremoniously.
With
dsTest = AssociationThread[{"a", "b"}, If[Last@# == 10000, ...
- asked by Edmund (9 votes), answered by JasonB (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Is there an open source implementation of Mathematica-the-language?] http://mathematica.stackexchange.com/questions/4454/is-there-an-open-source-implementation-of-mathematica-the-language
I’ve seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
- asked by sblom (81 votes), answered by Simon (63 votes)
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[What are the most common pitfalls awaiting new users?] http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by Dr. belisarius (341 votes), answered by Michael E2 (195 votes)
================================== Can you answer these? ==================================
[Enable file completion by default?] http://mathematica.stackexchange.com/questions/127203/enable-file-completion-by-default
File completions work for Import and Get but not with << syntax as you can see:
Is there some way to enable this?
- asked by M.R. (2 votes)
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[Trouble with NIntegrate strategy "DoubleExponentialOscillatory" when trying to ListPlot the results] http://mathematica.stackexchange.com/questions/126832/trouble-with-nintegrate-strategy-doubleexponentialoscillatory-when-trying-to-l
Can someone point me in the right direction? I ’ve been puzzling with this for weeks...
I have a huge function (of the form f(y,)sin(x) ) to integrate in in region (0, Infinity) and I use ...
- asked by George13 (1 vote)
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[Using an umlaut for a keyboard shortcut] http://mathematica.stackexchange.com/questions/126909/using-an-umlaut-for-a-keyboard-shortcut
How can I define a keyboard shortcut based on an umlaut like ü?
KeyEvent in KeyEventTranslations.tr doesn’t seem to register umlaut based keyboard inputs. For example, after adding
...
- asked by Karsten 7. (3 votes)
================================== Top new questions this week: ==================================
[The paradigm behind Dynamic and related functionality] http://mathematica.stackexchange.com/questions/126471/the-paradigm-behind-dynamic-and-related-functionality
Dynamic and the related functionality strikes me as a very unique way to build quick and dirty personal GUIs which are great for experimentation.
I suspect that this is only because of my lack of ...
- asked by Szabolcs (24 votes), answered by Leonid Shifrin (21 votes)
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[Bug with iterated With: Referring to function arguments invalidates previous definitions] http://mathematica.stackexchange.com/questions/126425/bug-with-iterated-with-referring-to-function-arguments-invalidates-previous-def
G[x_] := With[{a = 0}, With[{b = x}, a]] G @ 0 F[x_] := With[{a = 0}, {b = x}, a] F @ 0 gives 0 a
I would expect both to behave exactly the same.
It seems that referring to the parameter ...
- asked by masterxilo (20 votes), answered by Kuba (20 votes)
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[How to quickly find all grid cells covered by a geometric region?] http://mathematica.stackexchange.com/questions/126346/how-to-quickly-find-all-grid-cells-covered-by-a-geometric-region
I’m trying to compute a complete set of unit grid cells ("pixels") which a geometric region covers at least partially. I have constructed a method that produces correct results:
With[{reg = ...
- asked by kirma (14 votes), answered by george2079 (9 votes)
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[Cone Trees: map a graph onto geometric shape] http://mathematica.stackexchange.com/questions/126657/cone-trees-map-a-graph-onto-geometric-shape
Question
Is it possible to map a Graph onto a geometric object such as a Cone?
Motivation
Visualizing large trees can be tedious, especially when limited to the confines of the printed page. One ...
- asked by SumNeuron (13 votes), answered by Szabolcs (18 votes)
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[Evaluate expressions within Vim] http://mathematica.stackexchange.com/questions/126449/evaluate-expressions-within-vim
I want to be able to type a quick Mathematica expression, such as
550/3. (e.g. common math), Sum[i, {i, 0, n}]//TeXForm//ToString (e.g. writing LaTeX document), or {55, 1, 10, 40, 9}//Total (e.g. ...
- asked by Andrew MacFie (11 votes), answered by Andrew MacFie (11 votes)
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[Non newtonian calculus] http://mathematica.stackexchange.com/questions/126730/non-newtonian-calculus
I would like to define a new operator say
\(\text {stard}[f[x]] = \lim _{h\rightarrow 0}\left (\frac {f[x+h]}{f[x]}\right )^{\frac {1}{h}}\)
I think it must be done with an upvalue but I do not know how to ...
- asked by cyrille.piatecki (10 votes), answered by Szabolcs (18 votes)
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[How could I perform Region or Polygon Clipping in mathematica?] http://mathematica.stackexchange.com/questions/126463/how-could-i-perform-region-or-polygon-clipping-in-mathematica
I need to clip several regions reg: like Rectangle, Polygon, Ellipse... My goal isn’t to plot the clipping but to have a representation of each new region.
I searched if there was any package or ...
- asked by A.M. (10 votes), answered by george2079 (4 votes)
================================== Greatest hits from previous weeks: ==================================
[Beautiful dance of the Earth and Venus around the sun] http://mathematica.stackexchange.com/questions/115358/beautiful-dance-of-the-earth-and-venus-around-the-sun
I have seen very nice dynamic graphics created by users of Ma. I would like to get help whether the following graphics can be created using Ma. I was not able to create the dynamic picture here. ...
- asked by ramesh (12 votes), answered by ubpdqn (6 votes)
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[How can this image (optical illusion) be created with Mathematica?] http://mathematica.stackexchange.com/questions/24148/how-can-this-image-optical-illusion-be-created-with-mathematica
I came across this image the other day:
and liked the sensation of it pulsing. I was wondering if anyone would know how to create something similar with Mathematica (without the Pink Floyd Dark ...
- asked by Mike Honeychurch (53 votes), answered by halirutan (66 votes)
================================== Can you answer these? ==================================
[Smart Subscript] http://mathematica.stackexchange.com/questions/126736/smart-subscript
I have a question about subscript policy. For some reason I have some variables called Subscript[q, 1], Subscript[q, 2], Subscript[q, 3] and Subscript[q, 4]. I know that I could have called them in ...
- asked by MaPo (1 vote)
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[Difficult R installation] http://mathematica.stackexchange.com/questions/126501/difficult-r-installation
In RLink and R v3.0.1?, there is an update which say that the problem of the lack of compatibility between the expected version and the last version of R has been settled for version 10.0.1 of ...
- asked by cyrille.piatecki (2 votes)
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[Does Overflow[] poison session for N?] http://mathematica.stackexchange.com/questions/126337/does-overflow-poison-session-for-n
Summary: once Mathematica hits an overflow error, N[] appears to break for even simple calculations.
RealDigits[N[Sqrt[2]-1,10^8]];
I was impressed that Mathematica ran the code above (first 100 ...
- asked by barrycarter (9 votes)
================================== Top new questions this week: ==================================
[Drawing picture with straight line (Petros Vrellis’s Art)] http://mathematica.stackexchange.com/questions/126161/drawing-picture-with-straight-line-petros-vrelliss-art
I am trying to extend Writing a word with straight lines for any picture/image. I guess the basic idea is to find a set of points in the image region and then draw random lines through them. Let’s ...
- asked by Sumit (16 votes), answered by Rahul (6 votes)
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[How do I count the most used functions across a set of notebooks?] http://mathematica.stackexchange.com/questions/125960/how-do-i-count-the-most-used-functions-across-a-set-of-notebooks
WolframLanguageData allows us to view the most used functions across several code bases like Wolfram Alpha, the documentation, or Stack Exchange. I was curious about the results for my own collection ...
- asked by Michael Hale (15 votes), answered by Michael Hale (11 votes)
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[How to ReplaceAll except within specified heads] http://mathematica.stackexchange.com/questions/125918/how-to-replaceall-except-within-specified-heads
ReplaceAll[expr, rule] and ReplaceRepeated[expr, rule] search through all subexpressions of expr applying rule where they match.
Are there built-in Mathematica functions that do the same thing, ...
- asked by QuantumDot (15 votes), answered by JHM (15 votes)
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[Is this a bug in Replace?] http://mathematica.stackexchange.com/questions/125771/is-this-a-bug-in-replace
Consider the following minimal examples. This one works as expected, replacing trees starting from the inside with a numerical value.
ClearAll[tree]; x = tree["A", {tree["B", {1, 2}], 3}]; Replace[x, ...
- asked by István Zachar (14 votes), answered by Leonid Shifrin (17 votes)
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[How do I test if a variable represents a sequence?] http://mathematica.stackexchange.com/questions/126193/how-do-i-test-if-a-variable-represents-a-sequence
I created a variable that represents a sequence:
mySeq = Sequence[1, 2, 3];
I wanted to use that variable as an argument for some functions. But I got in trouble. For example,
FreeQ[mySeq, 1]
...
- asked by Fernando Saldanha (12 votes), answered by Edmund (8 votes)
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[How to calculate the numerical integral more efficiently?] http://mathematica.stackexchange.com/questions/126001/how-to-calculate-the-numerical-integral-more-efficiently
Rencently, I ecountered the following numerical intergral:
\begin{cases} \mathbf I_1=\displaystyle \int_{t}\mathbf N' {\mathbf N'}^{\text T}{\rm d}t\\ \mathbf I_2=\displaystyle \int_{t}\mathbf N''
- asked by Shutao Tang (11 votes), answered by Anton Antonov (8 votes)
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[Optional argument that can be completely omitted?] http://mathematica.stackexchange.com/questions/125929/optional-argument-that-can-be-completely-omitted
I am writing a simple function return similar words.
Clear[similarWords] similarWords[string_]:=Nearest[WordList[],string]
I want to add another argument n which is optional. When it presents, it ...
- asked by matheorem (11 votes), answered by Szabolcs (12 votes)
================================== Greatest hits from previous weeks: ==================================
[Writing a word with straight lines] http://mathematica.stackexchange.com/questions/113403/writing-a-word-with-straight-lines
Here is an interesting way to write a word: (it is from a poster for the International Museum Day 2006; I believe it even won an award at an international design competition)
by Boris Ljubicic. ...
- asked by VividD (71 votes), answered by Anton Antonov (32 votes)
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[Exporting graphics to PDF - huge file] http://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[\[Theta]], r Sin[\[Theta]], ...
- asked by Matthew Leingang (85 votes), answered by Heike (73 votes)
================================== Can you answer these? ==================================
[Finding covariation between datasets] http://mathematica.stackexchange.com/questions/125963/finding-covariation-between-datasets
For me this is a very fascinating problem, which I however lack the ability to deal with as well as the nomenclature to describe properly. (Please feel free to edit the title).
The conditions are the ...
- asked by MathLind (2 votes)
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[Wolfram math on windows using PBSPro cluster] http://mathematica.stackexchange.com/questions/125861/wolfram-math-on-windows-using-pbspro-cluster
A user wishes to use math application running on our PBSPpro cluster.
Our cluster is accessible to linux users, running qsub to submit their jobs.
We have math10.4 for our cluster users, with ...
- asked by Dvory (2 votes)
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[Unexpected view of a vectorial triad in a combination of a Plot3D with Graphics3D] http://mathematica.stackexchange.com/questions/126168/unexpected-view-of-a-vectorial-triad-in-a-combination-of-a-plot3d-with-graphics3
I am preparing an illustration for the lecture on differential geometry. In this demonstration I am illustrating the Monge parameterization of the surface:
R = {xx, yy, 55 + xx^2 - xx^3 - 2*yy^2}; (* ...
- asked by Alexei Boulbitch (2 votes)
================================== Top new questions this week: ==================================
[The Game of Hex in Mathematica] http://mathematica.stackexchange.com/questions/125460/the-game-of-hex-in-mathematica
The Game of Hex is a game originally developed by Nash, and it’s rules are very simple. You start out with a hexagonal tiling of some size:
There are two players. The game is in turns, and every ...
- asked by TreFox (31 votes), answered by C. E. (26 votes)
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[Visualize fraction] http://mathematica.stackexchange.com/questions/125209/visualize-fraction
I would like to visualize a fraction like the square root of 2 with Mathematica. I found this visualization of Pi in the internet and wonder how this would be done with Mathematica. The image shows ...
- asked by Arjihad (22 votes), answered by Kuba (20 votes)
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[Monad-like structures in Mathematica] http://mathematica.stackexchange.com/questions/125537/monad-like-structures-in-mathematica
I have been trying to code monad-like structures in Mathematica. However, I am facing some issues and I was wondering if anyone can help. I will give some background in the hope it can be useful to ...
- asked by Diogo Gomes (16 votes), answered by m_goldberg (6 votes)
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[paclets updating awareness and tracking] http://mathematica.stackexchange.com/questions/125199/paclets-updating-awareness-and-tracking
It turns out that some silent updating may be done in our computers with paclets. See for example here. How are we aware that something has been changed ? Can we track updating/versions of paclets ?
...
- asked by andre (16 votes)
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[Is it important that the front-end has a built-in parser?] http://mathematica.stackexchange.com/questions/125180/is-it-important-that-the-front-end-has-a-built-in-parser
The Notebook interface has a parser that seems aware of all operator-precedences, allowing us to step through the expressions (rather: Box-) hierarchy with Ctrl+.
This is extremely convenient, saving ...
- asked by masterxilo (15 votes), answered by John Fultz (18 votes)
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[Package organization] http://mathematica.stackexchange.com/questions/125579/package-organization
When writing a Mathematica package Foo, with functions f1, f2 and f3, one can use the template:
BeginPackage["Foo`"]; f1::usage = "f1[] ...."; f2::usage = "f2[] ...."; Begin["`Private`"]; f1[]:= ...
- asked by Pixor (14 votes), answered by Szabolcs (17 votes)
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[ClearAll::clloc - "Cannot clear local variable x" in Block[x, ...] - why?] http://mathematica.stackexchange.com/questions/125251/clearallclloc-cannot-clear-local-variable-x-in-blockx-why
Block[{x}, ClearAll@x] ClearAll::clloc: Cannot clear local variable x.
The documentation just says
An error occurs because ClearAll cannot be used with a local variable in Block:
and
...
- asked by masterxilo (14 votes)
================================== Greatest hits from previous weeks: ==================================
[Beautiful dance of the Earth and Venus around the sun] http://mathematica.stackexchange.com/questions/115358/beautiful-dance-of-the-earth-and-venus-around-the-sun
I have seen very nice dynamic graphics created by users of Ma. I would like to get help whether the following graphics can be created using Ma. I was not able to create the dynamic picture here. ...
- asked by ramesh (11 votes), answered by ubpdqn (6 votes)
—————————-
[How can I draw the Olympic rings with Mathematica?] http://mathematica.stackexchange.com/questions/8885/how-can-i-draw-the-olympic-rings-with-mathematica
How can I draw the 5 interlocking Olympic rings with Mathematica?
(SVG version)
Edit
Hard choice, but some pretty cool answers here. I didn’t have 3D answers in mind when I posted the question, ...
- asked by Mike Honeychurch (41 votes), answered by cormullion (18 votes)
================================== Can you answer these? ==================================
[Creating notebooks with specific options being editable but not saveable] http://mathematica.stackexchange.com/questions/125676/creating-notebooks-with-specific-options-being-editable-but-not-saveable
The goal
is to create a notebook whose options, when the notebook is opened, are fixed regardless of edits done to the notebook.
E.g. WindowSize -> Automatic and WindowMargins -> 30 should be ...
- asked by Kuba (8 votes)
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[Possible bug with Dataset formatting for incompatible shapes and Missing] http://mathematica.stackexchange.com/questions/125689/possible-bug-with-dataset-formatting-for-incompatible-shapes-and-missing
Bug introduced in 11.0.0
The problem:
{<|"a" -> Range[5]|>, <|"a" -> Missing["KeyAbsent", "a"]|>} // Dataset
More detailed example shows that 5 is the magic number and ...
- asked by Kuba (10 votes)
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[TensorContract applied twice] http://mathematica.stackexchange.com/questions/125588/tensorcontract-applied-twice
I have a very simple question about TensorContract command: I’m declaring
$Assumptions = {T \[Element] Arrays[{4, 4, 4, 4}], a \[Element] Arrays[{4, 4}], b \[Element] Arrays[{4, 4}]};
so T is a ...
- asked by MaPo (3 votes)
================================== Top new questions this week: ==================================
[How to make a Spherical Cow?] http://mathematica.stackexchange.com/questions/125043/how-to-make-a-spherical-cow
Being a theoretical physicist, I always have a great respect for Spherical Cow. So I thought about making one myself. I am not sure how can I create (something considered to be the simplest!) this ...
- asked by Sumit (29 votes), answered by andre (41 votes)
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[Unit Discovery: Is this some sort of a sick joke?] http://mathematica.stackexchange.com/questions/124745/unit-discovery-is-this-some-sort-of-a-sick-joke
Alright, let’s have some fun here. I am essentially following the documentation by Wolfram, just looking at different quantities.
N[UnitConvert[Quantity["earth's gravity"]]] 9.80665m/(s)^2
Hmm, ...
- asked by Pirx (26 votes), answered by Xavier (27 votes)
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[Remove noise from data] http://mathematica.stackexchange.com/questions/124928/remove-noise-from-data
Hi, as you can see above I have some experimental data which has a large offset and shows clear noise fluctations around the tendency of the curve. I wanted to ask if someone could suggest me a ...
- asked by Filipe (23 votes), answered by nikie (22 votes)
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[Q&A Mathematica v.11 Neural Networks: A comprehensive look at Layers, Net Functions, and pioneering into this [[experimental]] code] http://mathematica.stackexchange.com/questions/124977/qa-mathematica-v-11-neural-networks-a-comprehensive-look-at-layers-net-functi
Motivation
As Mathematica v.11 was released earlier this month with a host of new [[experimental]] functions and a limited number of examples on curated data that do not cover all layers, options, ...
- asked by SumNeuron (20 votes), answered by Sebastian (12 votes)
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[Custom OpenerView with lazy evaluation] http://mathematica.stackexchange.com/questions/124892/custom-openerview-with-lazy-evaluation
OpenerView can be nested to create a hierarchical structure such as this:
One great aspect is that it remembers which lists are open and which are closed even after the parent has been closed and ...
- asked by C. E. (16 votes), answered by C. E. (7 votes)
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[RNN in Mathematica?] http://mathematica.stackexchange.com/questions/124988/rnn-in-mathematica
Recurrent neural network is an important part of machine learning and its improved version: LSTM network is widely applied, but Mathematica seemingly is in lack of these two features and in my ...
- asked by Wjx (15 votes), answered by Taliesin Beynon (19 votes)
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[Pentagonal spiral in Mathematica] http://mathematica.stackexchange.com/questions/125007/pentagonal-spiral-in-mathematica
I would like to plot an image of what I call a pentagonal spiral with Mathematica. A sample image of what I’d like to obtain is this (sorry for low-quality):
My initial idea was to get some kind of ...
- asked by bharb (14 votes), answered by Wjx (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Labeling individual curves in Mathematica] http://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (44 votes), answered by Artes (37 votes)
—————————-
[How to make this beautiful animation] http://mathematica.stackexchange.com/questions/112700/how-to-make-this-beautiful-animation
How to make an animation of following gif in Mathematica?
Edit: The animation shown above was created by Charlie Deck in processing.
And how to make 3D analog?
I tried first few steps
line = ...
- asked by vito (45 votes), answered by C. E. (48 votes)
================================== Can you answer these? ==================================
[WolframScript never exits (v11 only)] http://mathematica.stackexchange.com/questions/124667/wolframscript-never-exits-v11-only
after updating to version 11, I came across a problem with the execution of package files via bash.
The WolframScript program runs the entire code, but frequently it does not exit properly and as a ...
- asked by fabio.hipolito (5 votes)
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[Representing inequalties with proper boundaries] http://mathematica.stackexchange.com/questions/124747/representing-inequalties-with-proper-boundaries
I have a very simple problem: given an inequality, I’d like to represent it in a regional plot marking the boundary differently depending whether it belongs to the region or not. For example I’d like ...
- asked by Geon (3 votes)
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[StringTemplate performance issue] http://mathematica.stackexchange.com/questions/125087/stringtemplate-performance-issue
StringTemplate introduced in version 10 is very convenient in constructing formatted data. However, it seems to have a huge performance issue.
Consider this example:
data = RandomInteger[1, 100, ...
- asked by xslittlegrass (5 votes)
================================== Top new questions this week: ==================================
[GeoPosition coordinates from Shape file (.SHP) with unknown Datum] http://mathematica.stackexchange.com/questions/124121/geoposition-coordinates-from-shape-file-shp-with-unknown-datum
The City of Amsterdam supports an Open Data policy. Much information can be retrieved at the level of boroughs (stadsdelen). Unfortunately, GeoGraphics does not provide outlines of these smaller ...
- asked by Romke Bontekoe (12 votes), answered by JasonB (8 votes)
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[Detecting collisions in FEM] http://mathematica.stackexchange.com/questions/124324/detecting-collisions-in-fem
Say I want to study the deformation of a pitchfork when you have it fixed on the bottom and push one side.
<< NDSolve`FEM` = RegionDifference[Cuboid[{0, -5}, {1, 0}], Cuboid[{0.45, ...
- asked by tsuresuregusa (12 votes)
—————————-
[Discovering crosswords] http://mathematica.stackexchange.com/questions/124552/discovering-crosswords
I am trying to create a code that can identify the following terms: MATHEMATICA, STACK, EXCHANGE and USERS.
list1={"M","S","T","A","S","I","S","X","X","T","R","X"}; list2={"A ","T ","H ","X ","R ","X ...
- asked by Leandro Maciel de Carvalho (11 votes), answered by C. E. (15 votes)
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[29 Differential equations hang/not solved in version 11 compared to 10.4, looking for cause] http://mathematica.stackexchange.com/questions/124573/29-differential-equations-hang-not-solved-in-version-11-compared-to-10-4-lookin
I run Kamke differential equations in version 11 and compared the result to version 10.4. Found 29 differential equations that are no longer solved in version 11. Actually v11 hangs on these, eating ...
- asked by Nasser (11 votes)
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[Using predefined expressions as free variables in a pure function] http://mathematica.stackexchange.com/questions/124530/using-predefined-expressions-as-free-variables-in-a-pure-function
I want to have a function value of an expression where some variables are solutions to some set of equations, with some values of parameters. I had an idea to use pure functions for that.
However, ...
- asked by Picek (10 votes), answered by Alexey Popkov (4 votes)
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[How to delete unnecessary resistances in a resistance network] http://mathematica.stackexchange.com/questions/124475/how-to-delete-unnecessary-resistances-in-a-resistance-network
I’m still dealing with resistance network processing and got one problem left: how to delete unnecessary resistances?
Background
Let’s assume we are junior high students and know nothing about ...
- asked by Wjx (10 votes), answered by Sascha (5 votes)
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[Object detection in a low contrast image] http://mathematica.stackexchange.com/questions/124060/object-detection-in-a-low-contrast-image
I have a small dark object in the upper left corner of an image.
How can I separate it from the noisy rest and determine its IntensityCentroid?
The problem is that the objects intensity is not ...
- asked by mrz (10 votes), answered by Svyatoslav Korneev (12 votes)
================================== Greatest hits from previous weeks: ==================================
[Make a beautiful Moiré effect] http://mathematica.stackexchange.com/questions/112998/make-a-beautiful-moir%c3%a9-effect
How do I make the following Moiré pattern?
I tried:
A = Plot[Table[n, {n, 1, 30}], {x, 0, 31}, GridLines -> {Table[n, {n, 1, 30}], None}, GridLinesStyle -> AbsoluteThickness[1.2], ...
- asked by vito (23 votes), answered by gpap (34 votes)
—————————-
[Beautiful dance of the Earth and Venus around the sun] http://mathematica.stackexchange.com/questions/115358/beautiful-dance-of-the-earth-and-venus-around-the-sun
I have seen very nice dynamic graphics created by users of Ma. I would like to get help whether the following graphics can be created using Ma. I was not able to create the dynamic picture here. ...
- asked by ramesh (11 votes), answered by ubpdqn (6 votes)
================================== Can you answer these? ==================================
[CapForm bugged in V11?] http://mathematica.stackexchange.com/questions/124591/capform-bugged-in-v11
It appears on my system (OSX 10.10.5) that CapForm isn’t behaving itself in V11. Initially I thought it was a problem with the combination of CapForm and VertexColors but it seems even weirder than ...
- asked by Quantum_Oli (6 votes)
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[Linear tangent steering law and orbital insertion altitude] http://mathematica.stackexchange.com/questions/124489/linear-tangent-steering-law-and-orbital-insertion-altitude
I’ve been trying to figure out how to build a rocket launch simulation that allows the user to specify the desired altitude at which a payload will be inserted into a stable circular orbit, but have ...
- asked by AlexR (2 votes)
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[What is a "generic case"?] http://mathematica.stackexchange.com/questions/124347/what-is-a-generic-case
Introduction
With this question I am coming back to a long-standing issue I have with Mma’s concept of a "generically correct" result. The basic idea seems to be, vaguely, that if a result is true in ...
- asked by Pirx (6 votes)
================================== Top new questions this week: ==================================
[Can Mathematica put these puzzle pieces together?] http://mathematica.stackexchange.com/questions/123993/can-mathematica-put-these-puzzle-pieces-together
I have five DXF files with various geometric figures.
Are squares with a different geometric shape in each DXF file...
Four DXF files have a square with a different geometric shape on one side ...
- asked by Leandro Maciel de Carvalho (17 votes), answered by kirma (11 votes)
—————————-
[How to monitor the process of Neural Network Learning] http://mathematica.stackexchange.com/questions/123684/how-to-monitor-the-process-of-neural-network-learning
Main Problem
I’m exploring the neural network in v11 and I would like to monitor the training progress in my own way instead of Mathematica’s default way. So my question is, how to do this ...
- asked by Wjx (17 votes), answered by Taliesin Beynon (13 votes)
—————————-
[Changes to Coefficient function in v10.2] http://mathematica.stackexchange.com/questions/123565/changes-to-coefficient-function-in-v10-2
In the version Mathemaica 10.4, I am very surprised that the core function Coefficient has changed, e.g.,
Coefficient[3 x x + 8 y y - 24 x y, 2 x y] 0
In previous versions (e.g. v9.0.1, ...
- asked by Orders (17 votes)
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[Unexpected behaviour from Table[]] http://mathematica.stackexchange.com/questions/124046/unexpected-behaviour-from-table
The following code in Mathematica 11:
iList = {i, -10, 10, 2}; Table[i, iList] produces this result: {i, i, i, i}
Where in version 10 (and presumably earlier versions) it produced an error:
...
- asked by Bruce Crawford (16 votes), answered by Szabolcs (15 votes)
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[Can Mathematica act like a web server?] http://mathematica.stackexchange.com/questions/123805/can-mathematica-act-like-a-web-server
I have a Mathematica program that modifies images that I would like to make available for other people to use through the web. The input is only one parameter. So, for example, I could run it as a ...
- asked by Tyler Durden (16 votes)
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[How to generate all possible orderless partitions of a list according to another list?] http://mathematica.stackexchange.com/questions/123835/how-to-generate-all-possible-orderless-partitions-of-a-list-according-to-another
This question is hard to describe in plain text. So I will post an example and a working code (brute force) to illustrate.
For example I have a list: {1, 2, 3, 4, 5} and a partition list {2, 2, 1}. I ...
- asked by happy fish (15 votes), answered by Mr.Wizard (11 votes)
—————————-
[RandomPoint crashes kernel] http://mathematica.stackexchange.com/questions/123735/randompoint-crashes-kernel
Bug introduced in Version 11.0
Reported as CASE:3686963, 12 Aug 2016
I attempted to determine whether the problem with RandomPoint identified in my answer to question 89384 had been fixed in
...
- asked by bbgodfrey (12 votes), answered by ilian (6 votes)
================================== Greatest hits from previous weeks: ==================================
[How to Plot an Infinite Series] http://mathematica.stackexchange.com/questions/14083/how-to-plot-an-infinite-series
I want to sketch the graphs of \[u(t,x)=\frac {1}{2}+\sum _{n\geq 1} \frac {1}{n\pi } ((-1)^n-1)e^{-n^2t}\sin (nx)\] for \(t=0, 0.01, 0.1, 0.5, 1, 10\) on the same axes.
For \(t=0\), I input
Plot[{1/2 + ...
- asked by Vladimir (2 votes), answered by chris (9 votes)
—————————-
[How to make this beautiful animation] http://mathematica.stackexchange.com/questions/112700/how-to-make-this-beautiful-animation
How to make an animation of following gif in Mathematica?
Edit: The animation shown above was created by Charlie Deck in processing.
And how to make 3D analog?
I tried first few steps
line = ...
- asked by vito (45 votes), answered by C. E. (48 votes)
================================== Can you answer these? ==================================
[Holidays output] http://mathematica.stackexchange.com/questions/123763/holidays-output
I wanted to print out the holidays in Germany in 2016:
DayRange[DateObject[{2016, 1, 1}], DateObject[{2016, 12, 31}], "Holiday", HolidayCalendar -> {"Germany", "Bavaria"}]
The result list ...
- asked by mrz (2 votes)
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[How to crawl some website needed username and password] http://mathematica.stackexchange.com/questions/123771/how-to-crawl-some-website-needed-username-and-password
In version 11,if we want to crawl public website like wiki,we can do it like this:
URLRead["https://en.wikipedia.org/wiki/Wiki", "Body"]
But I don’t know how to crawl some website needed ...
- asked by yode (4 votes)
—————————-
[NFourierTransform of an interpolating function] http://mathematica.stackexchange.com/questions/123800/nfouriertransform-of-an-interpolating-function
I have an interpolating function called rs22 - a solution from NDSolve - which is defined from 0 to about 1 ms. rs22 is a function that reaches a non-zero equilibrium value. (only shown here up to ...
- asked by Shiki (3 votes)
================================== Top new questions this week: ==================================
[PostScript-like drawing in Mathematica?] http://mathematica.stackexchange.com/questions/123289/postscript-like-drawing-in-mathematica
To illustrate by example, construct an equilateral triangle in PostScript:
0 0 moveto %moveto origin 6 0 lineto %construct first line segment 6 0 translate %translate ...
- asked by Alan (14 votes), answered by WReach (21 votes)
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[Efficiently exchange elements between two lists] http://mathematica.stackexchange.com/questions/123221/efficiently-exchange-elements-between-two-lists
I have two lists with equal length, and I want to exchange the elements on every even positions. For example,
{{1, 2, 3, 4, 5}, {6, 7, 8, 9, 10}} will return {{1, 7, 3, 9, 5}, {6, 2, 8, 4, 10}} ...
- asked by happy fish (13 votes), answered by Kuba (12 votes)
—————————-
[Finite element simulation of Airy waves] http://mathematica.stackexchange.com/questions/122063/finite-element-simulation-of-airy-waves
I am attempting to solve for waves on a water surface starting with a two dimensional solution. The equations are that the water must satisfy Laplace’s equation everywhere with a time dependent ...
- asked by Hugh (13 votes), answered by user21 (10 votes)
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[How do you make a Neural Net?] http://mathematica.stackexchange.com/questions/123458/how-do-you-make-a-neural-net
In the new Mathematica release (v11), NeuralNetworks is one of the new main features. However, the documentation isn’t that clear on what function should be used in a Net.
The documentation on ...
- asked by JHM (12 votes), answered by Searke (13 votes)
—————————-
[How to plot data by counties?] http://mathematica.stackexchange.com/questions/123324/how-to-plot-data-by-counties
I’d like to plot county data as in this D3 example:
Is there a way to do this with GeoGraphics, or at least to get path polygons per county and then plot them with different colors?
The first ...
- asked by M.R. (11 votes), answered by C. E. (9 votes)
—————————-
[Why are delayed definitions in scoping functions NOT documented?] http://mathematica.stackexchange.com/questions/122061/why-are-delayed-definitions-in-scoping-functions-not-documented
As outlined here, := may be used in scoping constructs like With to give delayed definitions, but this is undocumented.
This has been in the language since at least Mathematica 4.0. It is very ...
- asked by Mr.Wizard (11 votes)
—————————-
[Shading under a curve with dots]http://mathematica.stackexchange.com/questions/123422/shading-under-a-curve-with-dots
I plotted the function \(y=x^2\) using the Plot command
Plot[x^2, {x,-5,5}]
I need to shade the area under the curve using a pattern (dots pattern), not using a solid color or a hue. Is it possible? ...
- asked by James (10 votes), answered by JasonB (14 votes)
================================== Greatest hits from previous weeks: ==================================
[General strategies to write big code in Mathematica?] http://mathematica.stackexchange.com/questions/109888/general-strategies-to-write-big-code-in-mathematica
I think after six months of exposure to Mathematica and the Wolfram Language I am fairly OK with writing short codes and snippets. However, what are some general strategies to use in order to write ...
- asked by Ali Hashmi (94 votes), answered by Leonid Shifrin (75 votes)
—————————-
[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (430 votes), answered by faysou (388 votes)
================================== Can you answer these? ==================================
[Can I use Mathematica as a constraint solver?] http://mathematica.stackexchange.com/questions/123487/can-i-use-mathematica-as-a-constraint-solver
I have been using SMT solvers for program analysis. Basically the idea is to translate x86 assembly code to SMT formulas and use the solver for automatic input test generation. There is a Microsoft ...
- asked by Edgar (1 vote)
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[Why is this function slower after a simple change?] http://mathematica.stackexchange.com/questions/122109/why-is-this-function-slower-after-a-simple-change
I have a function that calculates the rank of a restricted growth string defined like so,
rankKRGS[{}] = 0; rankKRGS[string_] := With[{n = Length@string, k = Max@string + 1, alone = ...
- asked by Jordy Dickinson (3 votes)
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[Is there an efficient way to monitor the progress of a task remotely?] http://mathematica.stackexchange.com/questions/123181/is-there-an-efficient-way-to-monitor-the-progress-of-a-task-remotely
Recently, I’ve been running Mathematica packages on a remote cluster using SSH (using, e.g. the command
nohup nice math -noprompt -run "<<myPackage.m" > myOutput &
so that the output ...
- asked by Nikhil Anand (2 votes)
================================== Top new questions this week: ==================================
[How can I detect locations of Go (aka Baduk, Weiqi) stones on a board?] http://mathematica.stackexchange.com/questions/121835/how-can-i-detect-locations-of-go-aka-baduk-weiqi-stones-on-a-board
The Goal
There are a couple apps that score a Go board from a photo. I was wondering if something like that would be possible with Mathematica. The key step is to detect the positions of the stones ...
- asked by Mark S. (19 votes), answered by halirutan (2 votes)
—————————-
[What are all the "magic" Symbols in the Mathematica language?] http://mathematica.stackexchange.com/questions/121981/what-are-all-the-magic-symbols-in-the-mathematica-language
Leonid Shifrin once wrote (excerpted):
(Unevaluated) is one of a very few "magic symbols", along with Sequence and Evaluate - these are deeply wired into the system and can not be easily ...
- asked by Mr.Wizard (16 votes), answered by Mr.Wizard (9 votes)
—————————-
[What has changed in pattern matching functions with the Orderless attribute?] http://mathematica.stackexchange.com/questions/121564/what-has-changed-in-pattern-matching-functions-with-the-orderless-attribute
In making an attempt to answer this question, we ran into a version-dependent pattern-matching issue. An extended discussion in the comments transpired, and some inconsistencies arose. Consider the ...
- asked by march (16 votes)
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[Converting a Sierpinski tetrahedron to a Graph] http://mathematica.stackexchange.com/questions/121553/converting-a-sierpinski-tetrahedron-to-a-graph
I need a representation of a 3D Sierpinski gasket as a graph to perform some simulations on. The 2D version is included in GraphData[], but the 3D one is nowhere to be found, so I was wondering if ...
- asked by FEARxxx (13 votes), answered by J. M. (2 votes)
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[Working with DynamicModule: SetDelayed + OwnValues] http://mathematica.stackexchange.com/questions/121584/working-with-dynamicmodule-setdelayed-ownvalues
Shortly, definitions in form of e.g. x:= RandomReal[] have to be avoided inside DynamicModule[{x}, ...]. Why?, this Prints immediately: DynamicModule[{x}, x := Print[1]; {}]
It hit us hard in the ...
- asked by Kuba (12 votes), answered by Kuba (13 votes)
—————————-
[How to speed up pattern matching] http://mathematica.stackexchange.com/questions/121911/how-to-speed-up-pattern-matching
Main Problem
Mr.Wizard posed this question when discussing another problem.
I reproduce the main part of Mr.Wizard’s problem here:
MatchQ[{1, 2, 3, 4, 5}, {x__?((Echo[##]; False) &), y__}]
On ...
- asked by Wjx (11 votes), answered by Michael E2 (5 votes)
—————————-
[How to efficiently implement k-FN (k-Furthest Neighbors)?] http://mathematica.stackexchange.com/questions/121541/how-to-efficiently-implement-k-fn-k-furthest-neighbors
I’d like to pick k points from a set of points in n-dimensions that are approximately "maximally apart" (sum of pairwise distances is almost maxed). What is an efficient way to do this in MMA? Using ...
- asked by M.R. (10 votes), answered by C. Woods (2 votes)
================================== Greatest hits from previous weeks: ==================================
[Writing a word with straight lines] http://mathematica.stackexchange.com/questions/113403/writing-a-word-with-straight-lines
Here is an interesting way to write a word: (it is from a poster for the International Museum Day 2006; I believe it even won an award at an international design competition)
by Boris Ljubicic. ...
- asked by VividD (70 votes), answered by Anton Antonov (32 votes)
—————————-
[Make a beautiful Moiré effect] http://mathematica.stackexchange.com/questions/112998/make-a-beautiful-moir%c3%a9-effect
How do I make the following Moiré pattern?
I tried:
A = Plot[Table[n, {n, 1, 30}], {x, 0, 31}, GridLines -> {Table[n, {n, 1, 30}], None}, GridLinesStyle -> AbsoluteThickness[1.2], ...
- asked by vito (23 votes), answered by gpap (34 votes)
================================== Can you answer these? ==================================
[Looking for a package for finite mappings] http://mathematica.stackexchange.com/questions/121776/looking-for-a-package-for-finite-mappings
I am looking for a package for dealing with "mappings" \(f\colon A\to B\) where \(A\) and \(B\) are finite subsets of the set of all possible (inert) expressions.
I need operations like:
Computing \(f(a)\) ...
- asked by masterxilo (3 votes)
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[Using Palettes in Mathematica Online] http://mathematica.stackexchange.com/questions/121935/using-palettes-in-mathematica-online
my student is using the online version of Mathematica for my class; it appears to not have a palette feature for typing formatted input? This was kind of shocking to me; why wouldn’t there be a ...
- asked by Jake Mirra (1 vote)
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[Derivation of an interpolation function with multiple arguments] http://mathematica.stackexchange.com/questions/121599/derivation-of-an-interpolation-function-with-multiple-arguments
I have the following interpolation function:
f[x_,a_,b_]:=70 s[a,b][[1,1,2]][x] where s[a,b] is the solution of a differential equation. s[a_, b_] := NDSolve[{ H2[x] == Rx[x]^2 + G[x, a, b], ...
- asked by Maria (2 votes)
================================== Top new questions this week: ==================================
[Generate a certain colorful triangle] http://mathematica.stackexchange.com/questions/121353/generate-a-certain-colorful-triangle
I want to get a colorful triangle like this:
I hope to get a triangle with any number of layers. This is my current method. Actually, I’m not very content with these graph theory functions, since ...
- asked by yode (13 votes), answered by Mr.Wizard (7 votes)
—————————-
[Bad interaction between Join and ListPlot (or Plot)] http://mathematica.stackexchange.com/questions/121289/bad-interaction-between-join-and-listplot-or-plot
When you write this code:
tab = {{1, 1}}; tab = Join[tab, {{2,2}}]; you expect to get the following table: {{1, 1}, {2, 2}} but, if you write the following code instead: tab = {{1, 1}}; tab = ...
- asked by Francisco (11 votes), answered by C. E. (8 votes)
—————————-
[Handwriting recognition with Mathematica] http://mathematica.stackexchange.com/questions/121051/handwriting-recognition-with-mathematica
I am trying to teach Mathematica to read my handwriting. Since I don’t want to ruin my reputation by showing my own handwriting, I am going to use a font called blackjack.
Lets say this is a ...
- asked by Sumit (11 votes)
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[Can one effectively edit a Front End Resource that is already loaded?] http://mathematica.stackexchange.com/questions/121059/can-one-effectively-edit-a-front-end-resource-that-is-already-loaded
A number of special definitions are loaded from .tr files on Front End initialization and are accessible via FrontEndResource. These are used among other things for various menus and toolsbars, e.g.:
- asked by Mr.Wizard (11 votes)
—————————- [Bug with Compile and Log2?] http://mathematica.stackexchange.com/questions/121336/bug-with-compile-and-log2
It seems that Log2 in Compile gives numerical errors (CompiledFunction::cfn) if the input is not a power of 2.
For instance:
test1 = Compile[{{in, _Integer}}, Log2[in]]; test1[3]
gives an error ...
- asked by JHM (10 votes), answered by Michael E2 (4 votes)
—————————-
[What is the effect of giving ColorFunctionScaling a numerical argument?] http://mathematica.stackexchange.com/questions/121231/what-is-the-effect-of-giving-colorfunctionscaling-a-numerical-argument
(by making a mistake) I realised that ColorFunctionScaling can take a list of numerical arguments rather than just booleans. The following is true for ContourPlot and DensityPlot but not Plot3D and ...
- asked by gpap (10 votes), answered by Mr.Wizard (4 votes)
—————————-
[Reproducing the xkcd "Self-Description" comic] http://mathematica.stackexchange.com/questions/121160/reproducing-the-xkcd-self-description-comic
Trying to brush up on my programming, I wanted to see if I can reproduce at least the first two panels of the following comic in Mathematica:
I have some code for trying to reproduce the first ...
- asked by Mayumi It (10 votes), answered by Alexey Popkov (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Exporting graphics to PDF - huge file] http://mathematica.stackexchange.com/questions/1542/exporting-graphics-to-pdf-huge-file
I want to draw some basic surfaces, export them to PDF and include them in a LaTeX file. I create a simple 3D graphics object, for instance with
ParametricPlot3D[{r Cos[\[Theta]], r Sin[\[Theta]], ...
- asked by Matthew Leingang (84 votes), answered by Heike (71 votes)
—————————-
[Calculate the 2D Fourier transform of an Image] http://mathematica.stackexchange.com/questions/29203/calculate-the-2d-fourier-transform-of-an-image
I am new to Mathematica, and using version 8.0.
I would like to calculate the 2D Fourier Transform of an Image with Mathematica and plot the magnitude and phase spectrum, as well as reconstruct the ...
- asked by user8727 (2 votes), answered by Nasser (22 votes)
================================== Can you answer these? ==================================
[single slit diffraction numerical simulation] http://mathematica.stackexchange.com/questions/121474/single-slit-diffraction-numerical-simulation
I’m trying to simulate the Fraunhoffer diffraction at slits(single,double,triple) with Mathematica.
In the picture, the red one is analytical result and the green one is numerical result.
The ...
- asked by Taeshin Kim (5 votes)
—————————-
[How does the Contours->f_1, g1, f_2, g_2,... setting work?] http://mathematica.stackexchange.com/questions/121205/how-does-the-contours%e2%86%92f-1-g1-f-2-g-2-setting-work
I want to plot some wavefronts in Mathematica, and I’m having some trouble reining in one of the options for my ContourPlot3D.
More specifically, the documentation for ContourPlot3D says that the ...
- asked by Emilio Pisanty (5 votes)
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[Is every menu command equivalent to a command that can be executed within a notebook?] http://mathematica.stackexchange.com/questions/121453/is-every-menu-command-equivalent-to-a-command-that-can-be-executed-within-a-note
If so, is there a directory which gives the in-notebook command associated with each menu command ?
In particular, I would like to know how to replicate the menu command Evaluation -> Quit Kernel -> ...
- asked by Simon (3 votes)
================================== Top new questions this week: ==================================
[How can I better mimic the graphics at earth.nullschool.net?] http://mathematica.stackexchange.com/questions/120842/how-can-i-better-mimic-the-graphics-at-earth-nullschool-net
I’d like to be able to better mimic the graphics at earth.nullschool.net using Mathematica and I’m looking for suggestions for either improving my code or getting directed to some other approach.
...
- asked by Jim Baldwin (14 votes), answered by Simon Woods (15 votes)
—————————-
[how to permute list of number1,2,3,...,n,while preserve the order of first m terms as well as the last n-m terms?] http://mathematica.stackexchange.com/questions/120690/how-to-permute-list-of-number1-2-3-n-while-preserve-the-order-of-first-m-t
For example, starting from 1,2,3,4, I want to generate all permutations like 1,3,2,4,1,3,4,2,3,4,1,2 which preserve the order of e.g first two terms 1,2 and the order of e.g. last two terms ...
- asked by user41614 (12 votes), answered by Kuba (8 votes)
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[Create a polynomial of a given degree] http://mathematica.stackexchange.com/questions/120841/create-a-polynomial-of-a-given-degree
In Mathematica, how can I create a polynomial function in given variables of a given degree with unknown coefficents?
That is, I am looking for a function Poly[vars, degree] that generates, for ...
- asked by Posch79 (11 votes), answered by march (6 votes)
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[Fractal basins of attraction in a Magnetic Pendulum] http://mathematica.stackexchange.com/questions/120946/fractal-basins-of-attraction-in-a-magnetic-pendulum
I am trying to write a Mathematica program that realizes a graphical approximation of the basins of attraction in a Magnetic pendulum subject to friction and gravity, in which the three magnets are ...
- asked by bharb (10 votes), answered by C. E. (9 votes)
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[Draw half empty rectangle] http://mathematica.stackexchange.com/questions/120781/draw-half-empty-rectangle
How can I draw an half or a third filled rectangle? I want to make one rectangle frame with a unity width and then filled it according to a value between 0 and 1.
- asked by Miguel (9 votes), answered by Feyre (9 votes)
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[How to access "Choose Color Scheme" Programmatically] http://mathematica.stackexchange.com/questions/120999/how-to-access-choose-color-scheme-programmatically
I am designing an App and I want to use the "Choose Color Scheme" tools inside Button.
I am looking to have this tool in popup window when the Button is clicked but I can’t find the command to get ...
- asked by Algohi (8 votes), answered by Karsten 7. (9 votes)
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[Programming the fiver game] http://mathematica.stackexchange.com/questions/120959/programming-the-fiver-game
Obviously, even if I ask a lot of question I am, obviously, still a dummy!!!!
I want to program the fiver game. It’s a very simple game played solitary on a \(5 \times 5\) the rule is elementary : if ...
- asked by cyrille.piatecki (8 votes), answered by Mr.Wizard (15 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating 3D dice] http://mathematica.stackexchange.com/questions/110295/creating-3d-dice
How to create an image of a 3D die from the 2D images?
There is an example in the Documentation Center
I tried
but it doesn’t work.
- asked by vito (13 votes), answered by Martin Ender (21 votes)
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[xkcd-style graphs] http://mathematica.stackexchange.com/questions/11350/xkcd-style-graphs
I received an email to which I wanted to respond with a xkcd-style graph, but I couldn’t manage it. Everything I drew looked perfect, and I don’t have enough command over PlotLegends to have these ...
- asked by Amatya (518 votes), answered by Simon Woods (371 votes)
================================== Can you answer these? ==================================
[How to increase the image resolution of a map?] http://mathematica.stackexchange.com/questions/120572/how-to-increase-the-image-resolution-of-a-map
I’d like to obtain higher-resolution geographic maps retrieved from Wolfram geo server, since the standard resolution seems poor.
I tried to increase the "TileSize" parameter, like this:
...
- asked by Fred (2 votes)
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[Hidden Markov Model: emissions probabilities dependent on observable parameter] http://mathematica.stackexchange.com/questions/120700/hidden-markov-model-emissions-probabilities-dependent-on-observable-parameter
I need to fit an HMM where the emission probabilities (ep) are discrete and dependent on a known variable quantity. E.g.:
Imagine a daily time series of binary emissions ("1" or "2"). I suppose an ...
- asked by CupiDio (1 vote)
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[Why are there these jagged "shards" in my RegionPlot3D?] http://mathematica.stackexchange.com/questions/120712/why-are-there-these-jagged-shards-in-my-regionplot3d
I’m creating a region out of two component regions. Before anyone suggests it (because a lot of similar questions are about it), I don’t think the problem is increasing PlotPoints. I’ve increased it ...
- asked by YungHummmma (1 vote)
================================== Top new questions this week: ==================================
[How to extract the list of all matrices from a Block Diagonal Matrix?] http://mathematica.stackexchange.com/questions/120433/how-to-extract-the-list-of-all-matrices-from-a-block-diagonal-matrix
I am working on a function to do the opposite operation of How to form a block-diagonal Matrix from a list of matrices?
Here is my current algorithm: For i starting at 1, scan the elements of index ...
- asked by happy fish (11 votes), answered by yode (6 votes)
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[Collect all inputs from Documentation Center] http://mathematica.stackexchange.com/questions/120334/collect-all-inputs-from-documentation-center
Is it possible to collect all inputs programmatically from every function in the Documentation Center in a list and wrap them in a HoldComplete?
My case: With some fundamental functions modified, I ...
- asked by happy fish (9 votes), answered by Edmund (12 votes)
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[How to avoid procedural loops in this example?] http://mathematica.stackexchange.com/questions/120533/how-to-avoid-procedural-loops-in-this-example
I want to iterate over a list, and return the index as long as I found the first element satisfying my condition. Written in a for loop:
f[x_]:=2x For[i=1, i<=10, i++, If[f[i]==10, Return[i]] ] ...
- asked by Nick (8 votes), answered by Gerli (5 votes)
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[Why does this LibraryLink function crash?] http://mathematica.stackexchange.com/questions/120384/why-does-this-librarylink-function-crash
Recently, I have rewritten pure Wolfram Language implementation CAGDBSplineSurface[] with C. Below is main LibraryLink code:
LibraryLink Code
#include "WolframLibrary.h" ...
- asked by Shutao TANG (8 votes), answered by happy fish (11 votes)
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[How can I combine a list of Line[]’s into one continuous Line?] http://mathematica.stackexchange.com/questions/120285/how-can-i-combine-a-list-of-lines-into-one-continuous-line
I have a huge list of Lines. Take this one as an example:
linelist1 = {Line[{{0.15042300130733277`, 0.09918669845167598`}, {0.15124668865085406`, 0.09522452324491057`}}], ...
- asked by YungHummmma (8 votes), answered by Michael E2 (12 votes)
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[NIntegrate appears to give incorrect results] http://mathematica.stackexchange.com/questions/120118/nintegrate-appears-to-give-incorrect-results
I am trying to specify a bivariate probability density function in Mathematica. As a check, I would like to confirm that it integrates to one. Here is the function:
f[x1_, x2_, u1_, u2_, v11_, v22_, ...
- asked by Miguel (8 votes), answered by Anton Antonov (11 votes)
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[Which fonts are supported in Wolfram Cloud?] http://mathematica.stackexchange.com/questions/120102/which-fonts-are-supported-in-wolfram-cloud
I recently suggested creating dynamic community ads with Wolfram Cloud. @C.E. made a proof of concept ad to show that it works well.
Fonts are an important part of graphics design. It is useful to ...
- asked by Szabolcs (8 votes), answered by Szabolcs (5 votes)
================================== Greatest hits from previous weeks: ==================================
[What is the best Mathematica tutorial for young people?] http://mathematica.stackexchange.com/questions/733/what-is-the-best-mathematica-tutorial-for-young-people
As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ...
- asked by noisy (44 votes), answered by Vitaliy Kaurov (23 votes)
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[Mathematica Minecraft] http://mathematica.stackexchange.com/questions/19669/mathematica-minecraft
Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
- asked by faleichik (140 votes), answered by faleichik (192 votes)
================================== Can you answer these? ==================================
[integrate giving wrong result] http://mathematica.stackexchange.com/questions/120495/integrate-giving-wrong-result
A question with the same title has been asked many times, but I can’t find the solution of my problem in their answers. The integral I am trying to calculate is
Integrate[Sin[q ]^2 / Sinh[q]^2, {q, ...
- asked by Felix (7 votes)
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[Why FinancialDerivative fails for the Spread case?] http://mathematica.stackexchange.com/questions/120277/why-financialderivative-fails-for-the-spread-case
According to the documentation center for FinancialDerivative in version 10.4, when there are multi assets, we still may use FinancialDerivative with the corresponding correlation matrix to find the ...
- asked by M.J.2 (2 votes)
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[What does the GraphLayout -> "SpectralEmbedding" option do (mean) when displaying a graph?] http://mathematica.stackexchange.com/questions/120139/what-does-the-graphlayout-spectralembedding-option-do-mean-when-displayin
I have some relational data represented as a graph. As such some of the relational properties can be recognized. When I use the GraphLayout -> "SpectralEmbedding" option a very nice and sharply ...
- asked by Phillip Dukes (5 votes)
================================== Top new questions this week: ==================================
[Which Object-oriented paradigm approach to use in Mathematica?] http://mathematica.stackexchange.com/questions/119991/which-object-oriented-paradigm-approach-to-use-in-mathematica
Which Object-Oriented Paradigm (OOP) approach to use in Mathematica for:
general implementation, or a particular project?
There are a lot of related questions and answers in MSE on doing OOP that ...
- asked by Anton Antonov (14 votes)
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[How can I use Mathematica to sort the US Congressional Districts by PerimeterœArea] http://mathematica.stackexchange.com/questions/119944/how-can-i-use-mathematica-to-sort-the-us-congressional-districts-by-perimeter%c3%b7ar
The United States is divided into 435 congressional districts. Some of their shapes can be really strange due to gerrymandering. I think that I can find very gerrymandered congressional districts if ...
- asked by QuantumDot (13 votes), answered by Emilio Pisanty (6 votes)
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[Gillespie Stochastic Simulation Algorithm] http://mathematica.stackexchange.com/questions/119786/gillespie-stochastic-simulation-algorithm
The Gillespie SSA is a Monte Carlo stochastic simulation algorithm to find the trajectory a dynamic system described by a reaction (or interaction) network, e.g. chemical reactions or ecological ...
- asked by István Zachar (13 votes), answered by István Zachar (15 votes)
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[How to create a fascinating QR code like this?] http://mathematica.stackexchange.com/questions/120041/how-to-create-a-fascinating-qr-code-like-this
Check the facinating QRCode in my profile page here
You can find that this QRCode is some sort of intriguing as the QRCode is a IMAGE ITSELF!!!
So my question is, how to create such a QRCode ...
- asked by Wjx (11 votes), answered by Wjx (11 votes)
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[Data extraction from a picture of a graph] http://mathematica.stackexchange.com/questions/119666/data-extraction-from-a-picture-of-a-graph
How can I extract data from this picture of a graph?
i = Import["http://i.stack.imgur.com/Ac8m0.png"];
The caption of the picture reads: " Two-dimensional histogram values measured . Tick labels ...
- asked by psimeson (10 votes), answered by Simon Woods (16 votes)
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[Evaluating summations involving Fibonacci numbers in terms of Fibonacci numbers] http://mathematica.stackexchange.com/questions/119822/evaluating-summations-involving-fibonacci-numbers-in-terms-of-fibonacci-numbers
There are many summations involving Fibonacci numbers which Mathematica 10.4 is able to evaluate directly in terms of Fibonacci numbers. For example, Mathematica evaluates the summation given below as ...
- asked by John M. Campbell (9 votes), answered by yarchik (4 votes)
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[TreeForm outputs different results for the same inputs but why?] http://mathematica.stackexchange.com/questions/119745/treeform-outputs-different-results-for-the-same-inputs-but-why
First of all, please look at the below inputs and outputs:
In[1]:= $a = Array[# Range[#] &, {5}] Out[1]= {{1}, {2, 4}, {3, 6, 9}, {4, 8, 12, 16}, {5, 10, 15, 20, 25}} In[2]:= $af = Flatten[$a, ...
- asked by Taiki Bessho (8 votes), answered by JasonB (11 votes)
================================== Greatest hits from previous weeks: ==================================
[How to plot an ellipse?] http://mathematica.stackexchange.com/questions/20100/how-to-plot-an-ellipse
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting some errors. Is there something wrong ...
- asked by Sriram (6 votes), answered by Jens (15 votes)
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[Is it possible to draw this figure using Mathematica?] http://mathematica.stackexchange.com/questions/110848/is-it-possible-to-draw-this-figure-using-mathematica
The figure is
See the how-to video or a speeded-up GIF.
I believe it should be possible to draw this figure programmatically using some Random function, but I’m rather new to Mathematica, so I ...
- asked by AccidentalFourierTransform (50 votes), answered by M.R. (75 votes)
================================== Can you answer these? ==================================
[Hide Notebook scrollbars] http://mathematica.stackexchange.com/questions/119665/hide-notebook-scrollbars
Is it possible to hide the scrollbars from the notebook windows while still being able to use the mousewheel to scroll? Since I never click on the bars themselves they’re just a waste of space. It’s ...
- asked by Ray (3 votes)
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[Hold Values of DensityPlot to use for an other DensityPlot] http://mathematica.stackexchange.com/questions/120022/hold-values-of-densityplot-to-use-for-an-other-densityplot
I have two surface functions, f[x,y] and g[x,y]. Assuming that the DensityPlot of f and g takes a while, is there a way to hold the values of DensityPlot, to efficiently DensityPlot f[x,y]-g[x,y] ?
...
- asked by Pierre L. (1 vote)
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[How to place window on second screen?] http://mathematica.stackexchange.com/questions/119835/how-to-place-window-on-second-screen
I am trying to open a window on a second screen (a thunderbolt display attached to a macbook pro) that is the full size of the second screen. Here is the command I use:
ThunderboltDimensions = 2560, ...
- asked by abwatson (1 vote)
================================== Top new questions this week: ==================================
[Is the renaming mechanism of ‘With‘ flawed?] http://mathematica.stackexchange.com/questions/119403/is-the-renaming-mechanism-of-with-flawed
I’m confused about the renaming mechanism of With:
With[{x = a}, Hold[With[{a = b}, a + 2 x]]] (*==>Hold[With[{a$ = b}, a$ + 2 a]]*) With[{x = a$}, Hold[With[{a = b}, a + 2 x]]] ...
- asked by luyuwuli (21 votes), answered by Leonid Shifrin (22 votes)
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[How do I increase the readability of this code?] http://mathematica.stackexchange.com/questions/119074/how-do-i-increase-the-readability-of-this-code
Below is some code I am working on; being a beginner. How can I increase the readability of the part behind Manipulate?
I can’t read my own code anymore, because it is simply too long and unordered. ...
- asked by Imre Vegh (20 votes), answered by E.Doroskevic (16 votes)
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[Mysterious behaviour of Pick] http://mathematica.stackexchange.com/questions/119223/mysterious-behaviour-of-pick
As everyone knows, Pick can do amazing things, The most facinating phenomenon is that it can pick though all sorts of lists:
The basic & pattern matching: Pick[{4, 5, 6}, {1, 2, 1}, 1] (*{4,6}*) ...
- asked by Wjx (18 votes), answered by WReach (25 votes)
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[How to debug the C code for LibraryLink?] http://mathematica.stackexchange.com/questions/119053/how-to-debug-the-c-code-for-librarylink
Recently, I use the C to rewrite a Mathematica function NonzeroBasis[], please see here for fully descriptions.
Here, NonzeroBasis[i,p,u,U] calculates the values of ...
- asked by Shutao TANG (11 votes), answered by Szabolcs (16 votes)
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[Is it possible to attach a debugger to a dynamically linked library on the supported OS?] http://mathematica.stackexchange.com/questions/119083/is-it-possible-to-attach-a-debugger-to-a-dynamically-linked-library-on-the-suppo
Recently, I discovered that LibraryLink technique is a very useful tool to improve the performance of function. Firstly, I need to use LibraryLink template to write C/C++ program. Then compiling the ...
- asked by Shutao TANG (10 votes), answered by user21 (3 votes)
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[Nothing not behaving as expected?] http://mathematica.stackexchange.com/questions/119239/nothing-not-behaving-as-expected
I was thinking that Nothing was doing the same job as the vanishing sequence ##&[]. Yet this exemple shows it doesn't. Association[If[True,Nothing]] (*returns Association[Nothing]*) ...
- asked by faysou (10 votes), answered by Szabolcs (12 votes)
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[Random walk on a Sierpinski gasket] http://mathematica.stackexchange.com/questions/119036/random-walk-on-a-sierpinski-gasket
I am trying to simulate a random walk on a Sierpinski gasket. The best strategy i could come up with is to use Nearest point function to determine the next possible step of my walker. But this creates ...
- asked by FEARxxx (9 votes), answered by Wjx (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Creating legends for plots with multiple lines?] http://mathematica.stackexchange.com/questions/4025/creating-legends-for-plots-with-multiple-lines
So I have a graph with multiple lists, for e.g.
data = {{1,2}, {3,4}, {3,5}, {2,3} . . .} If I then do ListLinePlot[Table[{#1,Log[b,#2]}&@@@data, {b,1,10,2}]] I have no way to generate a legend ...
- asked by Eiyriou von Kauyf (58 votes), answered by Jens (88 votes)
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[How can this image (optical illusion) be created with Mathematica?] http://mathematica.stackexchange.com/questions/24148/how-can-this-image-optical-illusion-be-created-with-mathematica
I came across this image the other day:
and liked the sensation of it pulsing. I was wondering if anyone would know how to create something similar with Mathematica (without the Pink Floyd Dark ...
- asked by Mike Honeychurch (51 votes), answered by halirutan (65 votes)
================================== Can you answer these? ==================================
[Is pattern matching just systematic guessing and checking?] http://mathematica.stackexchange.com/questions/119394/is-pattern-matching-just-systematic-guessing-and-checking
How does the pattern matcher work?
how does it match this example?
f[3, h[4]] /. f[x_, z_[y_]] :> {x, y, z}
My guess is that the pattern matcher collects all the names in the expression f[3, ...
- asked by John Conor Cosnett (3 votes)
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[How can I move he documentation to another location after install on Windows?] http://mathematica.stackexchange.com/questions/119503/how-can-i-move-he-documentation-to-another-location-after-install-on-windows
How can I move he documentation to another location after install on Windows?
I would like to move the documentation to another partition on my Windows filesystem. Michael Hale in chat recommended ...
- asked by jamesson (4 votes)
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[How to perform convolutions on this complicated pdf?] http://mathematica.stackexchange.com/questions/119034/how-to-perform-convolutions-on-this-complicated-pdf
For a known pdf f[x], I need to calculate integrals over the probability density of the sum of Log[f[x]] over independent samples:
\[Q[t,n]\equiv P(\sum _{i=1}^{n}Log[f[x_{i}]]=t)\]
Since the sample ...
- asked by Jerry Guern (2 votes)
================================== Top new questions this week: ==================================
[\(3D\) graphic of soccer ball] http://mathematica.stackexchange.com/questions/118604/3d-graphic-of-soccer-ball
How to make a soccer ball \(3D\) graphic?
The following image is from Wikipedia, Spherical polyhedron:
Truncated icosahedron (left) and standard soccer ball (right)
...
- asked by vito (23 votes), answered by Michael E2 (23 votes)
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[The character sequence "
. d" triggers line break in strings]
http://mathematica.stackexchange.com/questions/118801/the-character-sequence-d-triggers-line-break-in-strings
Bug introduced in 7.0 or earlier and persists through 10.4.1
Bug isn’t present in version 5.2
Update: Sjoerd pointed out that this happens with any string and it is not related to StringForm. Just ...
- asked by Szabolcs (14 votes), answered by Sjoerd C. de Vries (12 votes)
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[Inconsistent handling of Dynamic option values; intended, omission, or bug?] http://mathematica.stackexchange.com/questions/118646/inconsistent-handling-of-dynamic-option-values-intended-omission-or-bug
In answering Dynamic ClipPlanes calculated from current ViewPoint Kuba and I got into a brief exchange regarding how Option values wrapped in Dynamic should be handled. For background John Fultz ...
- asked by Mr.Wizard (14 votes)
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[How can I plot this spirally surface?] http://mathematica.stackexchange.com/questions/118887/how-can-i-plot-this-spirally-surface
I would like to plot a surface that looks something like this sand spiral.
But I really have no idea how. Ideally I would like to be able to express this as a function in cartesian coordinates. I’m ...
- asked by user41147 (12 votes), answered by Thies Heidecke (28 votes)
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[Any manual on cell grouping management?] http://mathematica.stackexchange.com/questions/118649/any-manual-on-cell-grouping-management
Recently I come back to the problem of cell grouping and performed extensive search on this site and on MathGroup archive for information on how to use the possible values of the CellGroupingRules ...
- asked by Alexey Popkov (12 votes)
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[How can Mathematica be used to create Images like these?] http://mathematica.stackexchange.com/questions/118992/how-can-mathematica-be-used-to-create-images-like-these
Here are two examples of artistic image interpolation using just black lines. The first link shows the desired result created by an artist and the second done with C#.
TRIANGULATION: ANGULAR ...
- asked by R Hall (11 votes), answered by MarcoB (10 votes)
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[How to implement custom NIntegrate integration strategies?] http://mathematica.stackexchange.com/questions/118920/how-to-implement-custom-nintegrate-integration-strategies
How can new integration strategies algorithms be used with NIntegrate?
This is a different type of extension than the extensions with new integration rules, as described in the answer for the ...
- asked by Anton Antonov (10 votes), answered by Anton Antonov (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Fit image of mountain to gaussian] http://mathematica.stackexchange.com/questions/109946/fit-image-of-mountain-to-gaussian
I want to detect the edges of an image of a mountain and then fit that to a gaussian.
I am unsure about how to only get the mountain edge, rather than every single edge in the image.
How do I ...
- asked by olliepower (13 votes), answered by Dr. belisarius (14 votes)
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[How to find the position of elements in a list satisfying criteria] http://mathematica.stackexchange.com/questions/180/how-to-find-the-position-of-elements-in-a-list-satisfying-criteria
Say I have a list x={2,4,6,8,10} and I want to find out the positions of the elements that are greater than 7. Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
- asked by PeterR (32 votes), answered by J. M. (29 votes)
================================== Can you answer these? ==================================
[Softmax Regression Classification Algorithm] http://mathematica.stackexchange.com/questions/118958/softmax-regression-classification-algorithm
I’m following the Stanford Machine Learning course while simultaneously developing my Mathematica abilities. I’m having issues with my Softmax Classifier implementation (for ref, have a look at these ...
- asked by Frederik Brinck Jensen (4 votes)
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[Protected Variable Error with Workbench 3.0] http://mathematica.stackexchange.com/questions/118919/protected-variable-error-with-workbench-3-0
I have Wolfram Workbench 3.0, build 78, with Mathematica 10.4 as the front end. I am using Windows 10. I am trying to run a simple test source code test.m:
fun[x_] := x^2;
I have an empty notebook ...
- asked by S2167 (2 votes)
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[Putting the elements of a list inside another list] http://mathematica.stackexchange.com/questions/118837/putting-the-elements-of-a-list-inside-another-list
I have the list list1 = 1, 3, 4, 5, 6 and want to put the elements of this list inside a list of 0’s, list2 = 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, where each element of list1 will be in the ...
- asked by user41129 (1 vote)
================================== Top new questions this week: ==================================
[Are you interested in a Wolfram Workbench Update?] http://mathematica.stackexchange.com/questions/118154/are-you-interested-in-a-wolfram-workbench-update
I also posted this on the Wolfram Community site (link below)
Last week I attended the Wolfram Tour (which was great). I asked whenever we could expect a new version of Workbench, as the current ...
- asked by Frank Martin (18 votes), answered by Anton Antonov (14 votes)
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[Is manual adjustment of AccuracyGoal and PrecisionGoal useless?] http://mathematica.stackexchange.com/questions/118249/is-manual-adjustment-of-accuracygoal-and-precisiongoal-useless
This is a problem confusing me for years.
AccuracyGoal and PrecisionGoal are two options that I never truly understand and, to be honest, always avoid touching. Let’s first look at the descriptions ...
- asked by xzczd (15 votes)
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[Can Mathematica recompose an image?] http://mathematica.stackexchange.com/questions/117892/can-mathematica-recompose-an-image
The OP in this post on superuser.com asks how to recompose an image; quoting:
I have a set of images, which are parts of a bigger image.
I would like the images to assembled as automated as ...
- asked by mattiav27 (15 votes), answered by C. E. (13 votes)
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[How to implement custom integration rules for use by NIntegrate] http://mathematica.stackexchange.com/questions/118324/how-to-implement-custom-integration-rules-for-use-by-nintegrate
How can NIntegrate be extended with custom implementation of integration rules?
This answer of the question "Monte Carlo integration with random numbers generated from a Gaussian distribution" shows ...
- asked by Anton Antonov (14 votes), answered by Anton Antonov (15 votes)
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[Unexpected behavior of Sequence – using Sequence to delete parts of an expression] http://mathematica.stackexchange.com/questions/118108/unexpected-behavior-of-sequence-using-sequence-to-delete-parts-of-an-expressi
I thought that assigning Sequence[] to the part of an expression was an effective way to remove it. For example, the following code yields 2,3,4,5:
xx = Range[5]; xx[[1]] = Sequence[]; xx
Thus, I ...
- asked by Hector (10 votes), answered by Leonid Shifrin (6 votes)
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[Why NIntegrate is badly-behaved on \(J_{\frac {9}{2}}(x)\) by default?] http://mathematica.stackexchange.com/questions/117888/why-nintegrate-is-badly-behaved-on-j-frac92x-by-default
A friend of mine showed me this example:
Plot[BesselJ[9/2, x], {x, 0, 1}, PlotLabel -> Style["The integrand seems to be simple", 14]] Integrate[BesselJ[9/2, x], {x, 0, 1}] // N (* ...
- asked by xzczd (10 votes), answered by Anton Antonov (6 votes)
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[How do I insert OwnValues inside a held expression without evaluating it?] http://mathematica.stackexchange.com/questions/118030/how-do-i-insert-ownvalues-inside-a-held-expression-without-evaluating-it
Here is a very long and complicated expression, which we abbreviate as a. I store it using SetDelayed because I want to perform algebraic manipulations on it:
ClearAll[a]; a := 1 + 1
Here is a ...
- asked by QuantumDot (9 votes), answered by Kuba (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (419 votes), answered by faysou (377 votes)
—————————-
[++ is dangerous for C programmers] http://mathematica.stackexchange.com/questions/107619/is-dangerous-for-c-programmers
I noticed this fact, that may be misleading for programmers used to C language.
In Mathematica, if you have a function f[] and an array v, and you write
v[[ f[] ]]++
the function f is called ...
- asked by Giovanni Resta (32 votes), answered by Mr.Wizard (24 votes)
================================== Can you answer these? ==================================
[Solve and design "water flow"] http://mathematica.stackexchange.com/questions/118183/solve-and-design-water-flow
In some strategy game I play, I’ll have to change the terrain to make the water flow in some specific way to fulfill my goal. The water flow changes with terrain so if I can change the terrain wisely ...
- asked by Wjx (5 votes)
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[Is there a way to figure out the "upper limit" of my PC’s computational ability in Mathematica?] http://mathematica.stackexchange.com/questions/117852/is-there-a-way-to-figure-out-the-upper-limit-of-my-pcs-computational-ability
I am doing some simulations with Finite Element Analysis (FEA) and part of it is forming a mesh in 3D and then using NDSolveValue to solve a differential equation on that mesh.
For some meshes, my ...
- asked by YungHummmma (2 votes)
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[Numerical testing of Hardy’s inequality] http://mathematica.stackexchange.com/questions/118061/numerical-testing-of-hardys-inequality
I want to check the following Hardy’s most fundamental inequality by using Mathematica:
\[\sum _{n=1}^\infty \left (\frac {A_n}{n}\right )^p<\left (\frac {p}{p-1}\right )^p\sum _{n=1}^\infty a_n^p\] ...
- asked by vito (2 votes)
================================== Top new questions this week: ==================================
[Bug with MapAt, Span, and Association?] http://mathematica.stackexchange.com/questions/116561/bug-with-mapat-span-and-association
Bug introduced in 10.0 and persisting through 10.4.1 or later
Related to Mapping (Query) a function at multiple locations in nested data via All, Span, it seems to me that the behavior of MapAt ...
- asked by Mr.Wizard (19 votes)
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[Joining points into 3D surface] http://mathematica.stackexchange.com/questions/117736/joining-points-into-3d-surface
This seems like a simple problem, but I can’t find any questions like it here so I’m making a new one. Apologies if I missed one.
I have a list of points contained in a file which can be visualized ...
- asked by Crepo (12 votes), answered by george2079 (6 votes)
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[How to check the validity of an option value] http://mathematica.stackexchange.com/questions/116623/how-to-check-the-validity-of-an-option-value
I have a user-defined function, func, which takes the following form:
func[arg1, arg2, options] Here is the actual code Options[func] = {opt1 -> Automatic, opt2 -> False, opt3 -> {1, ...
- asked by Shutao TANG (12 votes), answered by Leonid Shifrin (10 votes)
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[Why does the GeoGraphics Frame show different Latitude than GeoPosition?] http://mathematica.stackexchange.com/questions/116507/why-does-the-geographics-frame-show-different-latitude-than-geoposition
The map looks right, but the Latitude in the Frame looks wrong.
Am I making a mistake or is this a bug?
- asked by vonkohorn (12 votes), answered by jose (8 votes)
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[Rotate Geographic map] http://mathematica.stackexchange.com/questions/117744/rotate-geographic-map
I want the map to be rotated by -45 Degree. I want to coast to be horizontal (perfect -45 degree). I already have:
loc = GeoPosition[{52.57243, 5.51780}]; loc1 = GeoPosition[{52.57718, 5.52193}]; ...
- asked by Dennis (11 votes)
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[How to learn the LibraryLink technique for the newcomer?] http://mathematica.stackexchange.com/questions/116451/how-to-learn-the-librarylink-technique-for-the-newcomer
Description
For the built-in programming language(or called Wolfram Language) of Wolfram Mathematica, I think it is much easier and simpler to learn than other computer language(such as C/C++ or ...
- asked by Shutao TANG (11 votes), answered by Szabolcs (12 votes)
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[Nested association values validation. POJsO handling] http://mathematica.stackexchange.com/questions/116571/nested-association-values-validation-pojso-handling
Sometimes it is convenient to work in your package/app with "objects" like:
childObject = <| "id" -> 284, "text" -> "texttext", "property" -> <| "type" -> "String", ...
- asked by Kuba (9 votes), answered by Leonid Shifrin (5 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (417 votes), answered by faysou (376 votes)
—————————-
[How to create word clouds?] http://mathematica.stackexchange.com/questions/2334/how-to-create-word-clouds
Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ...
- asked by Istvan Zachar (126 votes), answered by Heike (105 votes)
================================== Can you answer these? ==================================
[What is the difference between getting a boundary mesh from ToBoundaryMesh vs doing it with ToElementMesh?] http://mathematica.stackexchange.com/questions/116559/what-is-the-difference-between-getting-a-boundary-mesh-from-toboundarymesh-vs-do
I am trying to figure out how to define and use meshes for FEM and NDSolve. I’ve figured out that if I want more resolution near my boundaries, I can use ToBoundaryMesh to first create the boundary ...
- asked by YungHummmma (4 votes)
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[Solving Differential Equation for derivative] http://mathematica.stackexchange.com/questions/117689/solving-differential-equation-for-derivative
I am new to mathematica and am trying to solve a differential equation. Actually, I am not entirely sure if the system can be called differential equation.
I am interested in finding out the second ...
- asked by JKJ (1 vote)
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[ShortestTour Problem with Constraints] http://mathematica.stackexchange.com/questions/116505/shortesttour-problem-with-constraints
I can solve a travelling salesman problem with FindShortestTour[], but couldn’t find any function to solve a shorest tour problem with additional constraints like cost, fuel capacity etc. How cam I ...
- asked by user40405 (3 votes)
================================== Top new questions this week: ==================================
[Determine whether points lie within a cow] http://mathematica.stackexchange.com/questions/116160/determine-whether-points-lie-within-a-cow
I would like to determine whether randomly-generated points
lX = RandomVariate[UniformDistribution[{-0.4, 0.4}], {1000}]; lY = RandomVariate[UniformDistribution[{-0.2, 0.2}], {1000}]; lZ = ...
- asked by ben18785 (18 votes), answered by Daniel Lichtblau (12 votes)
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[FindMinimum doesn’t increase step size when necessary] http://mathematica.stackexchange.com/questions/116295/findminimum-doesnt-increase-step-size-when-necessary
I’ve spent much time finding a minimal example demonstrating this problem with FindMinimum. Normally one faces this problem when fitting very large and complicated functions which cannot be posted ...
- asked by Alexey Popkov (13 votes)
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[Internal DynamicModule steals scope of external DynamicModule] http://mathematica.stackexchange.com/questions/116167/internal-dynamicmodule-steals-scope-of-external-dynamicmodule
I have two dynamic objects, one nested in the other. Both have their own functions defined, as follows. I have simplified them to the point where they don’t make much sense, but can still illustrate ...
- asked by Istvan Zachar (13 votes), answered by John Fultz (6 votes)
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[Opposite of Alternatives in a Rule] http://mathematica.stackexchange.com/questions/116302/opposite-of-alternatives-in-a-rule
Mathematica provides Alternatives, to match one of several patterns. In a rule, this is used as p1|p2|p3:>replacement. I would like to have the opposite logic: p1&p2&p3:>replacement ...
- asked by Bruno Le Floch (10 votes), answered by Bruno Le Floch (8 votes)
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[Symbolic and numeric limit disagreeing on branch cut of ArcTan] http://mathematica.stackexchange.com/questions/116183/symbolic-and-numeric-limit-disagreeing-on-branch-cut-of-arctan
Bug introduced after v8.0.4 and before v9.0.1, and persisting through v10.4.1.
Investigating comments to my previous question lead me to the following problem:
N[Limit[ ArcTan[Sqrt[-4 E^(I a)]], ...
- asked by Axel Boldt (9 votes), answered by bbgodfrey (9 votes)
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[Why does the global variable exist here, where it was declared only in Module?] http://mathematica.stackexchange.com/questions/116140/why-does-the-global-variable-exist-here-where-it-was-declared-only-in-module
Why does Mathematica choose the mechanism that makes the global variable a here while parsing?
In f := Module[{a}, a;] In ?a Out Global`a
I don’t understand why Mathematica goes in the way ...
- asked by Smart Humanism (8 votes), answered by Leonid Shifrin (15 votes)
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[Integrate and NIntegrate disagreeing over branch cut of Sqrt?] http://mathematica.stackexchange.com/questions/116041/integrate-and-nintegrate-disagreeing-over-branch-cut-of-sqrt
Bug introduced after v8.0.4 and before v9.0.1, and persisting through v10.4.1.
In Mathematica 10.2 I’m trying to integrate this piecewise continuous function, but Integrate and NIntegrate seem to ...
- asked by Axel Boldt (8 votes), answered by bbgodfrey (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Generating a Sierpinski carpet] http://mathematica.stackexchange.com/questions/22052/generating-a-sierpinski-carpet
I am trying to draw a Sierpinski_carpet
. I have code that works, but I think there is a
more elegant way to do than my way. Maybe I couls use Tuples or Permutations or some
similar function to ...
- asked by chyaong (43 votes), answered by Mr.Wizard (67 votes)
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[Drawing a square root spiral] http://mathematica.stackexchange.com/questions/66969/drawing-a-square-root-spiral
Here is a start. I’m looking for a nice way to draw it.
Graphics[{EdgeForm[Black], White, Polygon @ {{0, 0}, {-1, 0}, Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, Polygon @ {{0, ...
- asked by mathe (22 votes), answered by Bob Hanlon (18 votes)
================================== Can you answer these? ==================================
[Problem with Parallelization when using Packages] http://mathematica.stackexchange.com/questions/115862/problem-with-parallelization-when-using-packages
I tried to find a solution to my problem in several answers posted in MSE but due to lack of my knowledge on parallelization territory, I couldn’t figure out solution to my problem.
I have a big code ...
- asked by Algohi (4 votes)
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[Fourier transform of Exp[x]/x] http://mathematica.stackexchange.com/questions/116157/fourier-transform-of-expx-x
Could you please explain why Mathematica gives the following expression when taking Fourier transform of \(\exp (\lambda z)/\lambda \)? \[\frac {-\log (-z)+\log (z)}{\sqrt {2\pi }}\] Why the answer does not ...
- asked by Ivan Gankevich (4 votes)
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[Inconsistent behavior from RegionMeasure on the RegionIntersection between a Polygon and a Line] http://mathematica.stackexchange.com/questions/116083/inconsistent-behavior-from-regionmeasure-on-the-regionintersection-between-a-pol
Consider a Polygon with lines drawn between two of its vertices,
pgon = Get[ "https://gist.githubusercontent.com/jasondbiggs/\ 59cb7d4aa802bde68c9f6a5203ef698f/raw/\ ...
- asked by Jason is no longer a postdoc (1 vote)
================================== Top new questions this week: ==================================
[Pulsed NMR animation] http://mathematica.stackexchange.com/questions/115675/pulsed-nmr-animation
I’m new here and have never interacted with the community so excuse me if this has been asked before or if I format incorrectly or anything like that.
Anyway, I’m trying to make an animation for a ...
- asked by D. Sessions (13 votes), answered by Jack LaVigne (16 votes)
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[Plot 3D model of DNA in Mathematica] http://mathematica.stackexchange.com/questions/115491/plot-3d-model-of-dna-in-mathematica
My friend asked me if we can plot a 3D model of DNA (deoxyribonucleic acid) in Mathematica. However, I am not really familiar with this and I don’t know if Mathematica can do this. Could you answer ...
- asked by BlueSky (12 votes), answered by JasonB (23 votes)
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[Exclude overlapping lists while keeping disjoint- and sub-lists?] http://mathematica.stackexchange.com/questions/115545/exclude-overlapping-lists-while-keeping-disjoint-and-sub-lists
Consider a function f[l1_List,l2_List]
which is given lists of integers. Whenever two of
the lists contain completely disjoint sets of integers OR one of the lists is completely
contained in the ...
- asked by Kagaratsch (12 votes), answered by ciao (15 votes)
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[Beautiful dance of the Earth and Venus around the sun] http://mathematica.stackexchange.com/questions/115358/beautiful-dance-of-the-earth-and-venus-around-the-sun
I have seen very nice dynamic graphics created by users of Ma. I would like to get help whether the following graphics can be created using Ma. I was not able to create the dynamic picture here. ...
- asked by ramesh (11 votes), answered by ubpdqn (6 votes)
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[Second argument of BeginPackage with nested package loading] http://mathematica.stackexchange.com/questions/115502/second-argument-of-beginpackage-with-nested-package-loading
I naively thought that the second argument of BeginPackage can simply be used to ensure the loading and availability in the $ContextPath of additional packages.
Example:
(* Pack1.m *) ...
- asked by Szabolcs (11 votes), answered by Leonid Shifrin (7 votes)
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[How to correctly implement in a new function the scoping behavior of Table, Sum and other commands that use Block to localize iterators?] http://mathematica.stackexchange.com/questions/115722/how-to-correctly-implement-in-a-new-function-the-scoping-behavior-of-table-sum
It is documented that "Block is automatically used to localize values of iterators in iteration constructs such as Do, Sum, and Table." Therefore the dummy index (iterator) in a Sum is shielded ...
- asked by MaTECmatica (9 votes), answered by Leonid Shifrin (6 votes)
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[Parallelization works, but does not use all CPU power] http://mathematica.stackexchange.com/questions/115436/parallelization-works-but-does-not-use-all-cpu-power
I’ve written code which involves Parallelize@Cases. When I evaluate, I find that all 16 cores are being used, but not fully; in other words all cores are active, but the total CPU usage is only 50
...
- asked by Luther (8 votes), answered by Szabolcs (17 votes)
================================== Greatest hits from previous weeks: ==================================
[How was Mathematica built?] http://mathematica.stackexchange.com/questions/106020/how-was-mathematica-built
I’ve been wondering this for a while now: How was Mathematica built?
Is it written in Haskell? C++? I’d love to get a taste of the wizardry behind this incredible software.
- asked by Chet (17 votes), answered by Sjoerd C. de Vries (23 votes)
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[How do I clear all user defined symbols?] http://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
- asked by niklasfi (42 votes), answered by Artes (36 votes)
================================== Can you answer these? ==================================
[How can I define MakeBoxes for Inactive forms user-defined heads?] http://mathematica.stackexchange.com/questions/115638/how-can-i-define-makeboxes-for-inactive-forms-user-defined-heads
Here I define a MakeBoxes for Times:
MakeBoxes[p : Inactive[Times][args___], form_] := MakeBoxes[Interpretation[HoldForm@myHead[args], p], form] And it works as expected: Inactivate[Times[3, ...
- asked by QuantumDot (2 votes)
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[Quits Kernel during evaluation of CreateTopologies] http://mathematica.stackexchange.com/questions/115660/quits-kernel-during-evaluation-of-createtopologies
I am using Feynarts 3.9 and FeynCalc 9.0.1 with Mathematica 10. Every time I load FeynArts with FeynCalc and execute
t = CreateTopologies[1, 1 -> 2];
mathematica quits the kernel after a few ...
- asked by Heerak Banerjee (1 vote)
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[Inconsistent performance of code] http://mathematica.stackexchange.com/questions/115634/inconsistent-performance-of-code
I’m trying to do some optimizations to my code to make it run faster, but it seems that there are inconsistencies in the performance of the code. Namely, the codes have different performance in ...
- asked by xslittlegrass (5 votes)
================================== Top new questions this week: ==================================
[Speedup matrix number multiplication] http://mathematica.stackexchange.com/questions/115087/speedup-matrix-number-multiplication
Consider this simple matrix number multiplication:
lth = 200; mtx = RandomReal[{0, 1}, {lth, lth}]; ls = RandomReal[{0, 1}, {lth}]; Et = Function[{t}, Sin[(Pi t)/20] Sin[2 t]]; Etc = Compile[{{t, ...
- asked by xslittlegrass (15 votes), answered by xslittlegrass (5 votes)
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[Fit a function with an unusual side condition] http://mathematica.stackexchange.com/questions/114864/fit-a-function-with-an-unusual-side-condition
I have a set of measurement data and I try to fit there a function (a Exp[b x] + c Exp[d x] - o). I have two problems:
The fit function does not converge nor after \(500\) iterations. The fit function ...
- asked by Lutscher (12 votes), answered by Anton Antonov (15 votes)
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[Tips to move from functional programming to GUI-based applications] http://mathematica.stackexchange.com/questions/114984/tips-to-move-from-functional-programming-to-gui-based-applications
Even though this forum has some questions related to Mathematica programming tips I think that we still don’t have specific help for those who want to learn to efficiently create GUIs in Mathematica. ...
- asked by Ariel Sepulveda (11 votes), answered by Brian G (0 votes)
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[Longest common substring for multiple strings?] http://mathematica.stackexchange.com/questions/114979/longest-common-substring-for-multiple-strings
I’m looking for a way to get the longest common substring for multiple strings such as
{home/dir1/dir2/jmoasd.txt,home/dir1/dir2/ivbnoxcihv.txt,home/dir1/dir2/siuhgiuchv.txt}
should yield
...
- asked by nqduy (10 votes), answered by xslittlegrass (9 votes)
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[How does a Pringle lose its curvature?] http://mathematica.stackexchange.com/questions/115231/how-does-a-pringle-lose-its-curvature
Nom!
As part of a bigger project, I’ve was writing some code to calculate the scalar curvature of surfaces of the form \(z = f(x,y)\). This uses a general calculation of the scalar curvature to produce ...
- asked by Lucas (9 votes), answered by KraZug (9 votes)
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[How to make datasets display correctly?] http://mathematica.stackexchange.com/questions/115246/how-to-make-datasets-display-correctly
NB: The problem illustrated below is truly ubiquitous. I hope the examples given below are sufficiently different to demonstrate this fact, and to discourage answers that hinge on the details of the ...
- asked by kjo (9 votes), answered by Stefan R (9 votes)
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[How do I translate a list of English words into another language using an online translation service with Mathematica?] http://mathematica.stackexchange.com/questions/115141/how-do-i-translate-a-list-of-english-words-into-another-language-using-an-online
As far as I know, there are two posts on this topic: Can I use Mathematica to translate a English word to a Chinese characters? and *How can I use Mathematica to get the translated result from the ...
- asked by matheorem (9 votes), answered by Rashid (11 votes)
================================== Greatest hits from previous weeks: ==================================
[What is the best Mathematica tutorial for young people?] http://mathematica.stackexchange.com/questions/733/what-is-the-best-mathematica-tutorial-for-young-people
As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ...
- asked by noisy (43 votes), answered by Vitaliy Kaurov (23 votes)
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[How to make use of Associations?] http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (110 votes), answered by Leonid Shifrin (128 votes)
================================== Can you answer these? ==================================
[PearsonChiSquareTest for count/frequency data?] http://mathematica.stackexchange.com/questions/114905/pearsonchisquaretest-for-count-frequency-data
I read with interest a previous question on the PearsonChiSquareTest from a few years ago, and one answer was very helpful:
Performing a chi-square goodness of fit test
Have there been any updates ...
- asked by Jim (3 votes)
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[ParallelDo issue with SQLExecute (SQLite)] http://mathematica.stackexchange.com/questions/115263/paralleldo-issue-with-sqlexecute-sqlite
This code run as expected if I use Do[...], but if I use instead ParallelDo[...], as in the code bellow, the SQL INSERT statements seems to be completely ignored.
In both cases, the filename is ...
- asked by jss (2 votes)
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[Why does Kernels[] produce this error?] http://mathematica.stackexchange.com/questions/115100/why-does-kernels-produce-this-error
Most of times, on my PC, when Kernel[] is launched for the first time, produces this error:
Executed again returns .
Is it a clue of malfunctioning or is, for reason I’m unaware of, the way it ...
- asked by mitochondrial (3 votes)
================================== Top new questions this week: ==================================
[Understanding evaluation and typesetting] http://mathematica.stackexchange.com/questions/114305/understanding-evaluation-and-typesetting
Background
So, one could be surprised by the fact that:
Hold @ Grid[{{1, 2}}] (*or*) Hold @ Graphics @ Disk[]
This issue and methods of prevention are discussed in Prevent graphics render ...
- asked by Kuba (16 votes), answered by Alexey Popkov (7 votes)
—————————-
[Empty WhenEvent action crashes kernel] http://mathematica.stackexchange.com/questions/114314/empty-whenevent-action-crashes-kernel
Bug introduced in 9.0 and persisting through 10.4.1 WhenEvent is new in 9.0.
This is an example from the docs, slightly modified (action is wrapped in ), working as expected.
NDSolve[x’[t] == ...
- asked by Istvan Zachar (12 votes), answered by Istvan Zachar (3 votes)
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[Difference between = and Ctrl + =] http://mathematica.stackexchange.com/questions/114357/difference-between-and-ctrl
What is a difference between \(\textbf {=}\), and Ctrl + \(\textbf {=}\)?
For instance
there are some examples, but result is same.
and
- asked by vito (11 votes), answered by WReach (19 votes)
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[Is there a way to make links to functions in a notebook?] http://mathematica.stackexchange.com/questions/114342/is-there-a-way-to-make-links-to-functions-in-a-notebook
Frequently I’m working on a function that’s at the top of my notebook in a "functions" section, but I’m looking at the output of it in a lower "body" section of the notebook. When I want to edit the ...
- asked by YungHummmma (11 votes), answered by Mr.Wizard (11 votes)
—————————-
[Strategies to compensate for lack of multi-document interface?] http://mathematica.stackexchange.com/questions/114515/strategies-to-compensate-for-lack-of-multi-document-interface
I use Mathematica (Home Edition) to manage notes which live in a large number of different notebooks. In my case the notebooks (hundreds) are just organized using document names and file system ...
- asked by billc (10 votes), answered by Leonid Shifrin (10 votes)
—————————-
[Definition of Mod and Quotient with complex arguments] http://mathematica.stackexchange.com/questions/114361/definition-of-mod-and-quotient-with-complex-arguments
How are Mod and Quotient defined for three real/complex arguments? I wasn’t able to find the definition.
My main surprise so far when investigating their behavior is a discontinuity between real and ...
- asked by Bruno Le Floch (10 votes), answered by Chip Hurst (10 votes)
—————————-
[HighlightGraph Problem] http://mathematica.stackexchange.com/questions/114725/highlightgraph-problem
Bug introduced in 9.0 or earlier and persisting through 10.4.1
HighlightGraph does not work.
HighlightGraph[Graph[{{0, 0}, {0, 1}, {1, 0}, {1, 1}}, {{0, 0} \[UndirectedEdge] {0, 1}}], {{0, 0}, {0, ...
- asked by ZYX (8 votes), answered by Szabolcs (5 votes)
================================== Greatest hits from previous weeks: ==================================
[Labeling individual curves in Mathematica] http://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (42 votes), answered by Artes (36 votes)
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[Drawing a square root spiral] http://mathematica.stackexchange.com/questions/66969/drawing-a-square-root-spiral
Here is a start. I’m looking for a nice way to draw it.
Graphics[{EdgeForm[Black], White, Polygon @ {{0, 0}, {-1, 0}, Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, Polygon @ {{0, ...
- asked by mathe (22 votes), answered by Bob Hanlon (17 votes)
================================== Can you answer these? ==================================
[FrobeniusSolve: how does it work?] http://mathematica.stackexchange.com/questions/114308/frobeniussolve-how-does-it-work
Can someone suggest any reference to read? I would like to understand how the algorithm works.
- asked by Mirko Aveta (3 votes)
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[How to delete lines containing specific values from a matrix?] http://mathematica.stackexchange.com/questions/114709/how-to-delete-lines-containing-specific-values-from-a-matrix
I am doing some numerical computations and a few iterations return values that are obviously incorrect (some numerical integration problem, I suppose.). I have managed to set these values to zero but ...
- asked by Gabu (2 votes)
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[ImageSize not working correctly with Placed directive] http://mathematica.stackexchange.com/questions/114580/imagesize-not-working-correctly-with-placed-directive
It seems that having Placed inside Plot breaks the ImageSize specification:
cm = 72/2.54; plt = LogLogPlot[Exp[x], {x, 1, 3}, ImageSize -> 12 cm, AspectRatio -> 0.73, Frame -> ...
- asked by leosenko (2 votes)
================================== Top new questions this week: ==================================
[Find duplicates in list of InfiniteLine] http://mathematica.stackexchange.com/questions/114046/find-duplicates-in-list-of-infiniteline
MMA 10 introduced a new function, which can be very convenient: InfiniteLine.
Of course, two infinite lines can be described by different arguments: for example InfiniteLine[0,0,1,0] and ...
- asked by anderstood (14 votes), answered by kglr (12 votes)
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[Is there any harm or benefit to Removing unneeded private symbols in packages?] http://mathematica.stackexchange.com/questions/114106/is-there-any-harm-or-benefit-to-removing-unneeded-private-symbols-in-packages
One of the things I noticed is that in typical medium-to-large sized packages, a huge number of symbols are created in the myPackage‘Private context. You can see a list of them by running
? ...
- asked by QuantumDot (12 votes), answered by R. M. (18 votes)
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[Can Mathematica solve functional equations with nested variable?] http://mathematica.stackexchange.com/questions/114210/can-mathematica-solve-functional-equations-with-nested-variable
First, inline free form input can solve these equations:
But it seems no native Mathematica function can solve these, there is even an error page for equations of this form (nestdv).
Now my ...
- asked by happy fish (10 votes)
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[How to describe the convex hull of a set of points as an implicit region for optimization?] http://mathematica.stackexchange.com/questions/113689/how-to-describe-the-convex-hull-of-a-set-of-points-as-an-implicit-region-for-opt
Last edit: 2016-05-03
A.G.’s answer was the one helped me the most, see explanation at the end of this question.
Original question
In Mathematica you can create out of a set of points in 2D and 3D ...
- asked by Mauricio Lobos (10 votes), answered by A.G. (2 votes)
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[NDEigensystem returns incorrect eigenvalues for 2D coulomb problem, eigenfunctions contain discontinuity] http://mathematica.stackexchange.com/questions/113898/ndeigensystem-returns-incorrect-eigenvalues-for-2d-coulomb-problem-eigenfunctio
I posted a similar question a short time ago regarding the 3D Coulomb problem. Jens’ excellent answer to this thread allowed me to obtain the correct eigenvalues and eigenenergies for that system.
I ...
- asked by Matthew Brunetti (10 votes), answered by Jens (12 votes)
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[RandomInteger: speed with long lists] http://mathematica.stackexchange.com/questions/114047/randominteger-speed-with-long-lists
I noticed an interesting effect with RandomInteger when looking at the time to create \(10^8\) random integers. The following code lines all take about 0.5 seconds on a i7 Windows 64bit Laptop:
...
- asked by Eisbar (9 votes), answered by Daniel Lichtblau (8 votes)
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[Creating Saveable->False notebooks] http://mathematica.stackexchange.com/questions/113858/creating-saveable-false-notebooks
Bug introduced in 10.3 or earlier and persisting through 10.4.1
Reproduced on Windows 7, 10
I’m having difficulties with programmatic creation of non saveable notebooks on Windows with V10.4.1.
...
- asked by Kuba (9 votes), answered by Kuba (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make use of Associations?] http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (109 votes), answered by Leonid Shifrin (127 votes)
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[What are the most common pitfalls awaiting new users?] http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by Dr. belisarius (308 votes), answered by Michael E2 (177 votes)
================================== Can you answer these? ==================================
[Integrate producing bad result] http://mathematica.stackexchange.com/questions/113791/integrate-producing-bad-result
I noticed a bug in Mathematica. It computes incorrectly a definite integral
Integrate[y* Sqrt[(l1^2 - y^2) (l2^2 - y^2)]/(a^2 - y^2), {y, 0, l1}, Assumptions -> l2 > a > l1 > 0]
and ...
- asked by user1765636 (3 votes)
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[FindPeaks error " Expecting an image or graphics instead of"] http://mathematica.stackexchange.com/questions/113884/findpeaks-error-expecting-an-image-or-graphics-instead-of
I’m running Mathematica 10.3.1.0 on windows 7 Professional Sp.1 when I try to use FindPeaks I keep getting the following error, even when trying the example in the documentation.
I have done the ...
- asked by Phymonkey (2 votes)
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[How can I set notebook’s options without opening it?] http://mathematica.stackexchange.com/questions/113816/how-can-i-set-notebooks-options-without-opening-it
At present moment, to batch apply a change in a set of notebook I use a "brute force", rough, method:
(* simple example *) setBackgroundBlue[notebookFileName_] := Module[ {tempNb}, tempNb = ...
- asked by mitochondrial (3 votes)
================================== Top new questions this week: ==================================
[Writing a word with straight lines] http://mathematica.stackexchange.com/questions/113403/writing-a-word-with-straight-lines
Here is an interesting way to write a word: (it is from a poster for the International Museum Day 2006; I believe it even won an award at an international design competition)
by Boris Ljubicic. ...
- asked by VividD (59 votes), answered by Martin Buttner (54 votes)
—————————-
[Numerical inverse Laplace-Hankel transform for a highly oscillatory function] http://mathematica.stackexchange.com/questions/113240/numerical-inverse-laplace-hankel-transform-for-a-highly-oscillatory-function
When trying to reproduce the result of this paper about numerical solution of Lamb’s problem, I encountered the double integral (to be more precise, the 0-order inverse Hankel-Laplace transform) of a ...
- asked by xzczd (11 votes)
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[Fitting Stradivari’s scroll] http://mathematica.stackexchange.com/questions/113273/fitting-stradivaris-scroll
How can I find the simplest curve that gives me a scroll like this?
This is where I am at the moment and doing it by hand is becoming more and more cumbersome.
First, take a drawing of the scroll ...
- asked by tsuresuregusa (11 votes), answered by nikie (13 votes)
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[NDEigensystem cannot solve numerically the 3D Coulomb problem, while DSolve returns the right answer] http://mathematica.stackexchange.com/questions/113520/ndeigensystem-cannot-solve-numerically-the-3d-coulomb-problem-while-dsolve-retu
After having derived by hand the eigenvalues and eigenfunctions for the 3D and 2D hydrogen atom, I want to solve the systems numerically using Mathematica. I need to do this because my next step is to ...
- asked by Matthew Brunetti (9 votes), answered by user21 (4 votes)
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[Make the moon’s 3D gif] http://mathematica.stackexchange.com/questions/113217/make-the-moons-3d-gif
How do I make the following gif
I tried:
moon = Import[ "https://upload.wikimedia.org/wikipedia/commons/f/f0/Full_Moon_as_Seen_From_Denmark.jpg"]; {r, g, b} = ColorSeparate[ImageResize[moon, ...
- asked by vito (9 votes), answered by Kuba (13 votes)
—————————-
[How to generate this structure of a list without ‘While‘ and the like?] http://mathematica.stackexchange.com/questions/113307/how-to-generate-this-structure-of-a-list-without-while-and-the-like
I need to create a list that holds, for given integer d, the elements \(1,\ldots ,d,d+2,\ldots ,2d,2d+3,\ldots ,3d,3d+4,\ldots ,d^2\) where \(\ldots \) is just denoting increment by 1 until the next written ...
- asked by Lukas (8 votes), answered by ciao (3 votes)
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[Join a list with 6, 6, 2 dimensions with a list 6, 6 dimensions] http://mathematica.stackexchange.com/questions/113630/join-a-list-with-6-6-2-dimensions-with-a-list-6-6-dimensions
listA = {{a1, a2, a3, a4, a5, a6}, {b1, b2, b3, b4, b5, b6}, {c1, c2, c3, c4, c5, c6}, {d1, d2, d3, d4, d5, d6}, {e1, e2, e3, e4, e5, e6}, {f1, f2, f3, f4, f5, f6}} listB = {{{n1, p1}, {n2, p2}, ...
- asked by SPIL (7 votes), answered by Kuba (6 votes)
================================== Greatest hits from previous weeks: ==================================
[How to plot an ellipse?] http://mathematica.stackexchange.com/questions/20100/how-to-plot-an-ellipse
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting some errors. Is there something wrong ...
- asked by Sriram (5 votes), answered by Jens (15 votes)
—————————-
[Multivariable Taylor expansion does not work as expected] http://mathematica.stackexchange.com/questions/15023/multivariable-taylor-expansion-does-not-work-as-expected
The basic multivariable Taylor expansion formula around a point is as follows:
\[ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac {1}{2!}(\mathbf a \cdot ... \]
- asked by matheorem (24 votes), answered by Jens (29 votes)
================================== Can you answer these? ==================================
[JournalArticle does not react on the PointSize option] http://mathematica.stackexchange.com/questions/113547/journalarticle-does-not-react-on-the-pointsize-option
The Default StyleSheet recognizes the PointSize option for ListPlot:
ListPlot[Table[Table[{i, j*i}, {i, 1, 10}], {j, 1, 3}], PlotStyle -> {{Red, PointSize[0.1]}, {Blue, PointSize[0.05]}, ...
- asked by Alexei Boulbitch (2 votes)
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[How to trace the stylesheet directives responsible for the selected text’s appearance?] http://mathematica.stackexchange.com/questions/113495/how-to-trace-the-stylesheet-directives-responsible-for-the-selected-texts-appea
By way of example, in a typical Mathematica interactive session, one sees text content as shown below:
Three different text styles can be seen in this figure: input, output, and the style for the ...
- asked by kjo (5 votes)
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[How do I get my ZWO ASI120MM astro-camera to work in MMA?] http://mathematica.stackexchange.com/questions/113481/how-do-i-get-my-zwo-asi120mm-astro-camera-to-work-in-mma
I am using Windows 10 + MMA 10.4.1. I bought a ZWO ASI120MM astro camera which I want to use as a guiding camera during astrophotography. From this site (http://astronomy-imaging-camera.com/software/) ...
- asked by Max (2 votes)
================================== Top new questions this week: ==================================
[How to make this beautiful animation] http://mathematica.stackexchange.com/questions/112700/how-to-make-this-beautiful-animation
How to make an animation of following gif in Mathematica?
Edit: The animation shown above was created by Charlie Deck in processing.
And how to make 3D analog?
I tried first few steps
line = ...
- asked by vito (36 votes), answered by C. E. (38 votes)
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[Can you plot pure function without specifying variable?] http://mathematica.stackexchange.com/questions/112478/can-you-plot-pure-function-without-specifying-variable
Given a pure function, e.g. f=Sin[#]&
it is possible to plot it with introducing an arbitrary
local variable, e.g.,
Plot[f[x],x,0,1]
However, the introduction of a variable x seems ...
- asked by JeffDror (15 votes), answered by Jens (12 votes)
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[Vizualization of percolation paths] http://mathematica.stackexchange.com/questions/112878/vizualization-of-percolation-paths
I did a simple demonstration to illustrate the percolation theory for my students. The content is a conductive square network possessing electrodes at its top and bottom edges. Some randomly chosen ...
- asked by Alexei Boulbitch (13 votes), answered by Kuba (8 votes)
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[How to access FEM shape functions] http://mathematica.stackexchange.com/questions/112907/how-to-access-fem-shape-functions
A couple of days ago I asked here about surface meshes and plotting on surfaces.
Now I have another question: How can I access the surface or boundary element shape functions?
I would like to ...
- asked by AxelF (9 votes), answered by user21 (7 votes)
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[Finding peaks of curve with small values] http://mathematica.stackexchange.com/questions/112993/finding-peaks-of-curve-with-small-values
I have 2d data of which I want to find the peaks.
data << "http://pastebin.com/raw/EQFz1KFn"; peaks = FindPeaks[data[[All, 2]], 0, 0, -Infinity] // N
The magnitudes of the found peaks are ...
- asked by mrz (8 votes), answered by JasonB (11 votes)
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[Is there research about the Mathematica programming paradigm?] http://mathematica.stackexchange.com/questions/112920/is-there-research-about-the-mathematica-programming-paradigm
There seem to be lots of papers discussing the functional programming paradigm terminology for Haskell, such as monad, category theory, lambda calculus, *morphism, etc. People study concepts and ...
- asked by Eric (8 votes)
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[Constructing a graph from a distance matrix] http://mathematica.stackexchange.com/questions/112745/constructing-a-graph-from-a-distance-matrix
I have a set \(S\) of \(n\) 2-dimensional points. We can compute a distance matrix (Euclidean distance) for \(S\) using say this answer. I wish to form an \(n\)-vertex graph having the points \(S\) as vertices, ...
- asked by Juho (8 votes), answered by Martin Buttner (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Labeling individual curves in Mathematica] http://mathematica.stackexchange.com/questions/4444/labeling-individual-curves-in-mathematica
I need to create a plot for export and inclusion in a report. Is there a better way to label curves than PlotLegends? From what I’ve read and my personal experience, PlotLegends is pretty bad.
Is ...
- asked by Tianxiang Xiong (42 votes), answered by Artes (36 votes)
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[What is the best Mathematica tutorial for young people?] http://mathematica.stackexchange.com/questions/733/what-is-the-best-mathematica-tutorial-for-young-people
As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ...
- asked by noisy (43 votes), answered by Vitaliy Kaurov (23 votes)
================================== Can you answer these? ==================================
[Possible reduced GUI performance in 10.4] http://mathematica.stackexchange.com/questions/112526/possible-reduced-gui-performance-in-10-4
I have observed significantly reduced performance in GUI in Mathematica v10.4. This is especially visible in autocomplete feature delays. This is very evident when I turn some power saving features ...
- asked by leosenko (3 votes)
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[Why does Eigenvalues work for a matrix \(\{M\}\) but not \(\{\{M\}\}\)?] http://mathematica.stackexchange.com/questions/112619/why-does-eigenvalues-work-for-a-matrix-m-but-not-m
Suppose I have a matrix {{1, 2}, {3, 4}}
which I’ll call mat. In a blur of human error, I computed the eigenvalues of mat with an extra set of curly braces surrounding it. To my surprise, this ...
- asked by user170231 (3 votes)
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[Calculate the ESP Grid based on Density Grid] http://mathematica.stackexchange.com/questions/112872/calculate-the-esp-grid-based-on-density-grid
I want to build a fast way to convert a density grid file into a grid file of the respective electrostatic potential (ESP; also known as MEP, the molecular electrostatic potential).
This ...
- asked by pH13 - Yet another Philipp (3 votes)
================================== Top new questions this week: ==================================
[How to model wooden joints with mathematica’s FEM?] http://mathematica.stackexchange.com/questions/111960/how-to-model-wooden-joints-with-mathematicas-fem
This is a dovetail joint:
and I’d like to see the stresses and deformation on the joint.I haven’t seen any modeling of disconnected regions with FEM, only connected regions, so I’m curious if you ...
- asked by tsuresuregusa (16 votes), answered by user21 (6 votes) —————————-
[Possible Bug in ArrayMesh] http://mathematica.stackexchange.com/questions/111945/possible-bug-in-arraymesh
Suppose we have the following array from which we intend to create an ArrayMesh:
arr = {{{1, 1, 1}, {1, 0, 1}, {1, 1, 0}}, {{1, 1, 1}, {0, 1, 1}, {1, 1, 0}}, {{0, 1, 0}, {0, 1, 1}, {0, 0, 1}}};
...
- asked by RunnyKine (15 votes), answered by ilian (9 votes)
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[How to draw all paths from (1,1) to (n,n) by move (+1, 0) or (0, +1)?] http://mathematica.stackexchange.com/questions/112395/how-to-draw-all-paths-from-1-1-to-n-n-by-move-1-0-or-0-1
Now I can draw some grid:
But what I want(I’m sorry for the weird line. I have no image processing software in my mac...):
Please notice:
f(1, 1) = f(2, 1) = f(3, 1) = 1 f(1, 1) = f(1, 2) = ...
- asked by Sayakiss (14 votes), answered by wxffles (14 votes)
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[All the food WolframAlpha knows about] http://mathematica.stackexchange.com/questions/112104/all-the-food-wolframalpha-knows-about
I want to plot some nutritional values and do some computation with it.
Is there an analogue of CountryData[] to get a list of all the foods for which WA has information?
- asked by Andrea Di Biagio (12 votes), answered by C. E. (12 votes)
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[RegionNearest and neighborhoods] http://mathematica.stackexchange.com/questions/112264/regionnearest-and-neighborhoods
In this previous question we see that RegionNearest isn’t quite as ’capable’ as Nearest for some things.
Similarly, I need to be able to find a given neighborhood of points on a MeshRegion. With ...
- asked by flip (11 votes), answered by Simon Woods (10 votes)
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[How do I extract a matrix of only positive numbers given a set of assumptions?] http://mathematica.stackexchange.com/questions/111989/how-do-i-extract-a-matrix-of-only-positive-numbers-given-a-set-of-assumptions
I want to divide a matrix:
mat = {{a, 0, -b}, {d, a, 0}, {0, 0, -a}} with the following assumptions: a >= 0, b >= 0, d >= 0
Into two matrices, one containing the positive elements, and one ...
- asked by Luis Fernando (11 votes), answered by b.gatessucks (14 votes)
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[How to type text with an underbrace underneath it like: \(\underbrace {g...g}_{n-times}\)?] http://mathematica.stackexchange.com/questions/111970/how-to-type-text-with-an-underbrace-underneath-it-like-underbraceg-g-n-t
I want to use the underbrace "esc u esc" but have it placed underneath text. Like \[\underbrace {g...g}_{n-times}\]
in a mathematica text cell. Is it possible? Thanks
- asked by Craig (11 votes), answered by JasonB (16 votes)
================================== Greatest hits from previous weeks: ==================================
[How to plot an ellipse?] http://mathematica.stackexchange.com/questions/20100/how-to-plot-an-ellipse
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting some errors. Is there something wrong ...
- asked by Sriram (5 votes), answered by Jens (15 votes)
—————————-
[How to manipulate 2D plots?] http://mathematica.stackexchange.com/questions/7142/how-to-manipulate-2d-plots
When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ...
- asked by Istvan Zachar (94 votes), answered by Istvan Zachar (105 votes)
================================== Can you answer these? ==================================
[Possible Bug in LinearSolveFunction with Sparse Vectors] http://mathematica.stackexchange.com/questions/112313/possible-bug-in-linearsolvefunction-with-sparse-vectors
Bug introduced in 5.0 and persists through 10.4
LinearSolveFunction is new in 5.0
Consider the following set of equations and corresponding variables:
eqns1 ={2 x == 2 - 4 y, 3 y == 4 z, 2 z + 4 ...
- asked by RunnyKine (8 votes)
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[Why FoldList 5 times faster than Apply for matrix multiplication?] http://mathematica.stackexchange.com/questions/112125/why-foldlist-5-times-faster-than-apply-for-matrix-multiplication
Consider this list of \(2x2\) matrices:
list=RandomReal[{-2,2},{500,2,2}];
Now compare timings of Apply and FoldList for matrix multiplication:
t1=FoldList[Dot,list];//AbsoluteTiming (* 0.000324, ...
- asked by Lukas (6 votes)
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[Generating OpenCL C code] http://mathematica.stackexchange.com/questions/112127/generating-opencl-c-code
I’m trying to make an interactive complex function plotter using OpenCl. So far I can only
plot functions that I hardcode into the kernel by hand. I’d like to be able to use
ComplexExpand@#@f@(x + ...
- asked by ra91 (6 votes)
================================== Top new questions this week: ==================================
[Rounding the Corners of a Shape] http://mathematica.stackexchange.com/questions/111479/rounding-the-corners-of-a-shape
I was wondering whether there is an option in Mathematica that enables me to smooth the corners of a shape. The example I want to start with is the pentagon.
This can be crudely specified as
...
- asked by Mr S 100 (23 votes), answered by MarcoB (21 votes)
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[Writing functions with "Method" options] http://mathematica.stackexchange.com/questions/111666/writing-functions-with-method-options
I’d like to implement several behaviors for a particular function using a Method option added to the function definition:
Options[saveData] = {Method -> "Addition"}; saveData[vars_, opts : ...
- asked by dionys (14 votes), answered by Shutao TANG (7 votes)
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[Interpretation of the result of ?@] http://mathematica.stackexchange.com/questions/111394/interpretation-of-the-result-of
This might be a very trivial question but as a beginner, I don’t know the answer. I was exploring ? and after running a cell containing ?@, I got an interesting result:
However, I’m not sure about ...
- asked by MathX (13 votes), answered by m_goldberg (15 votes)
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[Ticks in v10 - a bug or undocumented change] http://mathematica.stackexchange.com/questions/111663/ticks-in-v10-a-bug-or-undocumented-change
Bug introduced in 10.0 and fixed in 10.4
In this post @Heike provides this code:
ticksfun[xmin_, xmax_] := Table[{10^i, Superscript[10, i]}, {i, Floor[Log10[xmin]], Ceiling[Log10[xmax]]}]
...
- asked by leosenko (12 votes), answered by rcollyer (8 votes)
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[Why is an empty list not tested by VectorQ?] http://mathematica.stackexchange.com/questions/111438/why-is-an-empty-list-not-tested-by-vectorq
I am a bit amazed by this behavior of VectorQ[ expr, test ]: VectorQ[ {}, NumberQ ] True
It seems that the test itself is never applied and thus does not matter, so NumericQ or OddQ for ...
- asked by gwr (11 votes), answered by Szabolcs (16 votes)
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[Matrix indexed by one number] http://mathematica.stackexchange.com/questions/111631/matrix-indexed-by-one-number
I’m trying to find a generic way (for arbitrary dimensions) to create a matrix like so
a[1] a[2]
a[3] a[4]
i.e where it is indexed by one number, instead of say Array[a, 2, 2] which gives
...
- asked by Henrik (10 votes), answered by Szabolcs (14 votes)
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[ErrorListPlot ignores some exact data points] http://mathematica.stackexchange.com/questions/111436/errorlistplot-ignores-some-exact-data-points
Possible bug? Or am I missing something / expecting too much?
Forgive the seemingly obscure data points but they’re where I’ve noticed a problem.
Needs["ErrorBarPlots`"] data = { {{(10 Pi)/8, 1}, ...
- asked by Quantum_Oli (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Generate two random numbers with constraints] http://mathematica.stackexchange.com/questions/97424/generate-two-random-numbers-with-constraints
I want to generate two random numbers, \(p\) and \(q\), between \(0.5\) and \(1\).
They are connected by the constraint \(1/(2q) > p\).
How do I generate \(p\) and \(q\)?
- asked by Chandan Datta (25 votes), answered by JasonB (11 votes)
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[Multivariable Taylor expansion does not work as expected] http://mathematica.stackexchange.com/questions/15023/multivariable-taylor-expansion-does-not-work-as-expected
The basic multivariable Taylor expansion formula around a point is as follows:
\[ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac {1}{2!}(\mathbf a \cdot \nabla )^2 f(\mathbf r) + \cdots \]
- asked by matheorem (24 votes), answered by Jens (29 votes)
================================== Can you answer these? ==================================
[Numerical Optimal Control] http://mathematica.stackexchange.com/questions/111375/numerical-optimal-control
It seems that most practical optimal control problems are only able to be solved numerically using a non-linear programming approach. As such, I was hoping to tackle the following optimal control ...
- asked by user7388 (3 votes)
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[How to define a custom 3D graphics primitive in Mathematica?] http://mathematica.stackexchange.com/questions/111403/how-to-define-a-custom-3d-graphics-primitive-in-mathematica
There are lots of basic graphics pimitive in Mathematica such as 2D- caseLine[], Circle[] and 3D case Cylinder[], BSplineSurface[],etc.
In general, they own the following usage if memory serves:
...
- asked by Shutao TANG (5 votes)
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[Can Mathematica reliably determine the equality of any two constructible numbers?] http://mathematica.stackexchange.com/questions/111615/can-mathematica-reliably-determine-the-equality-of-any-two-constructible-numbers
A constructible number is any number which can be expressed with only natural numbers and the operators \(+\), \(-\), \(\times \), \(/\), \(\sqrt {}\) (square root only). Is Mathematica’s Simplify or FullSimplify ...
- asked by Martin Buttner (3 votes)
================================== Top new questions this week: ==================================
[Is it possible to draw this figure using Mathematica?] http://mathematica.stackexchange.com/questions/110848/is-it-possible-to-draw-this-figure-using-mathematica
The figure is
See the how-to video or a speeded-up GIF.
I believe it should be possible to draw this figure programmatically using some Random function, but I’m rather new to Mathematica, so I ...
- asked by AccidentalFourierTransform (42 votes), answered by M.R. (65 votes)
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[Is there a simple strategy to determine whether a point is inside a boundary?] http://mathematica.stackexchange.com/questions/111114/is-there-a-simple-strategy-to-determine-whether-a-point-is-inside-a-boundary
For a ellipse \(E(\theta )\), which owns the parametric equation as follows:
\(\begin {cases} x = a \sin \theta + b \cos \theta + c \\ y = d \sin \theta + e \cos \theta + f \\ \end {cases}\)
Now, I have a ...
- asked by Shutao TANG (17 votes), answered by RunnyKine (19 votes)
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[How to divide the wine into two equal portions] http://mathematica.stackexchange.com/questions/111250/how-to-divide-the-wine-into-two-equal-portions
There is a 8-liter bottle is full of wine. There are two empty bottles that have capacity 5-liters and 3-liters. How can these three bottles be used to separate the wine into two 4-liter portions?
...
- asked by yode (14 votes), answered by Simon Woods (21 votes)
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[solve this probability problem symbolically] http://mathematica.stackexchange.com/questions/110789/solve-this-probability-problem-symbolically
Consider a unit square, Pick two points P and Q uniformly at random inside the square, What is the probability that |PQ|>1?
I tried solve this problem
...
- asked by mathe (11 votes), answered by ubpdqn (9 votes)
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[Radial distribution function] http://mathematica.stackexchange.com/questions/110743/radial-distribution-function
I have tried to rewrite my old IDL code to calculate the radial correlation function for a regular 2D crystal structure.
The theory behind this function is given here: ...
- asked by mrz (10 votes), answered by RunnyKine (11 votes)
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[How to plot GDPs in this way?] http://mathematica.stackexchange.com/questions/110901/how-to-plot-gdps-in-this-way
Actually the current answer is very wonderfull.The bouns just for someone can complete this question.
I found this interesting plot of how the relationship between the GDPs of different countries has ...
- asked by yode (10 votes), answered by C. E. (13 votes)
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[Interesting Progression of ParametricRegion: Bug?] http://mathematica.stackexchange.com/questions/110791/interesting-progression-of-parametricregion-bug
Consider the following ParametricRegion from an answer to this question:
region = ParametricRegion[{{(1 + r - 12 r^2 + 4 r^3)/(2 r - 2), z Sqrt[(4 r^2)/(r - 1)^2 (r - r^2 (r - 3)^2)]}, 2 ...
- asked by RunnyKine (10 votes)
================================== Greatest hits from previous weeks: ==================================
[How do I clear all user defined symbols?] http://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
- asked by niklasfi (41 votes), answered by Artes (34 votes)
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[How to create word clouds?] http://mathematica.stackexchange.com/questions/2334/how-to-create-word-clouds
Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ...
- asked by Istvan Zachar (126 votes), answered by Heike (105 votes)
================================== Can you answer these? ==================================
[Overlay Inside a Grid/Column/Row Not Working] http://mathematica.stackexchange.com/questions/110836/overlay-inside-a-grid-column-row-not-working
Here is a microscopy image of some cells I want to make measurements on with Mathematica:
In order to make some measurements of cells in a microscopy image I have written a simple dynamic overlay ...
- asked by user13999 (3 votes)
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[WeightedAdjacencyMatrix does not complete for Connected Graph] http://mathematica.stackexchange.com/questions/111007/weightedadjacencymatrix-does-not-complete-for-connected-graph
Please see code snippet below - I have a weighted, connected graph that models a software process using a DiscreteMarkovProcess. I set some of the edge weights to zero to "turn off" some of the ...
- asked by Chris Ruhl (3 votes)
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[Counting automorphisms that preserve a group action] http://mathematica.stackexchange.com/questions/111102/counting-automorphisms-that-preserve-a-group-action
Note: the math, I believe, is not the problem here. The issue is not that I get the wrong answer, just that my code does not terminate. So, if you do not feel comfortable with the problem below, I do ...
- asked by Gerald (5 votes)
================================== Top new questions this week: ==================================
[General techniques for creating complex animations] http://mathematica.stackexchange.com/questions/110190/general-techniques-for-creating-complex-animations
I love good animations of abstract concepts, and when I try to create them myself, I prefer doing so in code to make sure they are exact (and because some things are just way too fiddly to do by ...
- asked by Martin Buttner (23 votes), answered by LLlAMnYP (6 votes)
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[Is there a numerical method/built-in to calculate the boundary of a set of graphs?] http://mathematica.stackexchange.com/questions/110236/is-there-a-numerical-method-built-in-to-calculate-the-boundary-of-a-set-of-graph
Recently, I encounted a geometry problem in my work. For a curve-family that owns the following parametric equation: \[E(t,\theta )= \begin {pmatrix} x_E(t,\theta ) \\ y_E(t,\theta ) \end {pmatrix}\]
...
- asked by Shutao TANG (13 votes), answered by RunnyKine (8 votes)
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[Creating 3D dice] http://mathematica.stackexchange.com/questions/110295/creating-3d-dice
How to create an image of a 3D die from the 2D images?
There is an example in the Documentation Center
I tried
but it doesn’t work.
- asked by vito (13 votes), answered by Martin Buttner (20 votes)
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[Regression /Bug in DelaunayMesh from 10.3.1 to 10.4] http://mathematica.stackexchange.com/questions/110598/regression-bug-in-delaunaymesh-from-10-3-1-to-10-4
In answering this question, I realized the OP and I were obtaining different results from the alphaShapes2D code. This question was updated with additional point sets, but when I tried to use my ...
- asked by RunnyKine (12 votes)
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[Handling Kernel quit] http://mathematica.stackexchange.com/questions/110162/handling-kernel-quit
One can use $Epilog to do something when the Kernel is quit or put an end.m file next to the init.m.
For Wolfram System sessions, $Epilog is conventionally defined to read in a file named end.m.
...
- asked by Kuba (12 votes), answered by Mr.Wizard (7 votes)
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[What is the closest star to Earth other than the sun?] http://mathematica.stackexchange.com/questions/110559/what-is-the-closest-star-to-earth-other-than-the-sun
How to find the Sun’s nearest neighbor star using Mathematica? I tried
but it didn’t work
- asked by vito (10 votes), answered by Zviovich (26 votes)
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[Find the Panda - Dudolf panda puzzle] http://mathematica.stackexchange.com/questions/110497/find-the-panda-dudolf-panda-puzzle
I recently find this puzzle where you have to find the panda from a group of snowmen. Having a horrible eyesight I have to take help of mathematica to find it.
I start with assumption that all ...
- asked by Sumit (10 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make use of Associations?] http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (105 votes), answered by Leonid Shifrin (125 votes)
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[Mathematica 10.0.x freezes in Initializing kernels] http://mathematica.stackexchange.com/questions/92931/mathematica-10-0-x-freezes-in-initializing-kernels
Bug caused by paclet update and fixed by paclet update.
I updated to Windows 10 and have been running Mathematica fine on it for over a month. For some reason, it has just stopped working. I don’t ...
- asked by mitcheljh (67 votes), answered by ilian (84 votes)
================================== Can you answer these? ==================================
[SiegelTheta gives misleading message when the dimensions don’t match] http://mathematica.stackexchange.com/questions/110500/siegeltheta-gives-misleading-message-when-the-dimensions-dont-match
Bug introduced in 6.0 and persisting through 10.4
SiegelTheta is new in 6.0
In order to test the SiegelTheta function, I wanted to evaluate it for \(\mathbf s=\mathbf 0\) when \(\mathbf ...\)
- asked by Semiclassical (3 votes)
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[How do I invert a function with two arguments?] http://mathematica.stackexchange.com/questions/110146/how-do-i-invert-a-function-with-two-arguments
I begin with a function defined by
c[u_, mH_]
I won’t go into details because it comes from countless lines of partial differential equations, boundary conditions and perturbations. But suffice to ...
- asked by Ash Arsenault (2 votes)
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[Cell format for usage statements] http://mathematica.stackexchange.com/questions/110199/cell-format-for-usage-statements
The myFunc::usage statement is intended to be a simple summary of the symbol and its arguments. However, many users like myself opt out of using Workbench and prefer to maximize use of the Notebook ...
- asked by Robert (2 votes)
================================== Top new questions this week: ==================================
[General strategies to write big code in Mathematica?] http://mathematica.stackexchange.com/questions/109888/general-strategies-to-write-big-code-in-mathematica
I think after six months of exposure to Mathematica and the Wolfram Language I am fairly OK with writing short codes and snippets. However, what are some general strategies to use in order to write ...
- asked by Ali Hashmi (47 votes), answered by Leonid Shifrin (45 votes)
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[How to make the digits of Pi go around in a spiral like this?] http://mathematica.stackexchange.com/questions/109982/how-to-make-the-digits-of-%cf%80-go-around-in-a-spiral-like-this
Here is a start.
MapIndexed[Text[Reverse[First[RealDigits[Pi,10,252]]][[Tr@#2]],#]&, Table[{t Cos[t],t Sin[t]},{t,0,16Pi,0.2}]]//Graphics
- asked by mathe (32 votes), answered by Martin Buttner (40 votes)
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[Guidelines for planning custom GUI in Mathematica] http://mathematica.stackexchange.com/questions/109525/guidelines-for-planning-custom-gui-in-mathematica
Intro
Usually I don’t have to care (it hurts my brain though) about misaligned details, additional/missing pixels. But currently I’m participating in a project where the design matters and I have to ...
- asked by Kuba (27 votes)
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[Wrong labelling of contours with ListContourPlot] http://mathematica.stackexchange.com/questions/109778/wrong-labelling-of-contours-with-listcontourplot
Bug introduced in 9.0 or earlier and persisting through 10.4
Consider this example:
dat = Table[Re[Sqrt[1 - x^2 - y^2]], {x, -1.1, 1.1, 0.01}, {y, -1.1, 1.1, 0.01}];
Now pay special attention to ...
- asked by Szabolcs (16 votes), answered by Szabolcs (10 votes)
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[Fit image of mountain to gaussian] http://mathematica.stackexchange.com/questions/109946/fit-image-of-mountain-to-gaussian
I want to detect the edges of an image of a mountain and then fit that to a gaussian.
I am unsure about how to only get the mountain edge, rather than every single edge in the image.
How do I ...
- asked by olliepower (13 votes), answered by Dr. belisarius (13 votes)
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[What is a printer’s point?] http://mathematica.stackexchange.com/questions/109813/what-is-a-printers-point
According to the documentation it is a basic unit for size spec. WindowSize and ImageSize says:
I think all the statements below are correct yet I would like to know for sure:
Is this the same ...
- asked by Kuba (12 votes), answered by Silvia (5 votes)
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[A weird issue with Interval[$MaxNumber]] http://mathematica.stackexchange.com/questions/109597/a-weird-issue-with-intervalmaxnumber
From the Interval documentation:
For approximate machine- or arbitrary-precision numbers x, Interval[x] yields an interval reflecting the uncertainty in x.
$Version (* 10.4.0 for Microsoft ...
- asked by Vladimir Reshetnikov (12 votes), answered by The Vee (3 votes)
================================== Greatest hits from previous weeks: ==================================
[What is the best Mathematica tutorial for young people?] http://mathematica.stackexchange.com/questions/733/what-is-the-best-mathematica-tutorial-for-young-people
As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ...
- asked by noisy (43 votes), answered by Vitaliy Kaurov (23 votes)
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[Is Mathematica worth it for me?] http://mathematica.stackexchange.com/questions/100072/is-mathematica-worth-it-for-me
I’m 13 years old and in 7th grade. I’m currently in Algebra 1, and I have fallen in love with both math and programming.
When I came upon Mathematica, it was awesome. My two favorite things fused ...
- asked by TreFox (59 votes), answered by Pillsy (43 votes)
================================== Can you answer these? ==================================
[Building a classifier for images] http://mathematica.stackexchange.com/questions/109484/building-a-classifier-for-images
I tried to build a classifier for some images that I have with the following code:
class1 = Import /@ FileNames["*", "location1"]; class2 = Import /@ FileNames["*", "location2"];
...
- asked by soandos (2 votes)
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[AppearanceRules on multipage Web Form] http://mathematica.stackexchange.com/questions/109887/appearancerules-on-multipage-web-form
I’m attempting to make a web survey using FormFunction. To list the questions I am using AppearanceRules to give each page an individual title. I can’t find any documentation in regards to ...
- asked by Alex Krotz (4 votes)
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[Function output] http://mathematica.stackexchange.com/questions/109714/function-output
I would like a function that computes Cartesian product of two sets z=(Tuples@{#1,#2}), and computes the number of elements in this set(list) Length@z which have a x elements in #1 and y elements in ...
- asked by Gelios (2 votes)
================================== Top new questions this week: ==================================
[How to design CloudObjects with reasonable CloudCredit costs] http://mathematica.stackexchange.com/questions/109259/how-to-design-cloudobjects-with-reasonable-cloudcredit-costs
Note: I originally thought to post this as a non-answer/extended comment to this question; however I feared that I would end up hijacking the original question. It is likely a duplicate with the ...
- asked by bobthechemist (17 votes)
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[How to merge two screenshots into one image?] http://mathematica.stackexchange.com/questions/109196/how-to-merge-two-screenshots-into-one-image
I have two screenshots:
For a long screenshot picture I usually use PhotoShop to combine both images:
How do I use Mathematica to make an automated program to do this? This is my current ...
- asked by yode (13 votes), answered by Arnoud Buzing (13 votes)
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[Current (e.g., ca. 2016 / MMa 10 / WP 4+) best practices for embedding interactive content in WordPress?] http://mathematica.stackexchange.com/questions/109231/current-e-g-ca-2016-mma-10-wp-4-best-practices-for-embedding-interacti
My strategy, in the past, has been to embed interactive CDF files into my WordPress blog for student’s to use (Much like the Wolfram Demonstration Project).
As many know 1) the ’Plug in’ ...
- asked by flip (11 votes)
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[Getting data from FRED] http://mathematica.stackexchange.com/questions/109203/getting-data-from-fred
Mathematica V10.4 supports a service for connection to FRED. If you create a connection with
fred = ServiceConnect["FederalReserveEconomicData"]
(you need to have created a login id to be ...
- asked by George Wolfe (11 votes), answered by George Wolfe (4 votes)
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[Do[ ]s and Don’t[ ]s when teaching Mathematica in undergraduate courses] http://mathematica.stackexchange.com/questions/108987/do-s-and-dont-s-when-teaching-mathematica-in-undergraduate-courses
Question motivated by some horrific homework-related posts that I don’t dare to link:
What are the top Do’s and Dont’s when teaching Mathematica to undergrads?
I don’t ask for the design of a ...
- asked by Dr. belisarius (11 votes), answered by bobthechemist (10 votes)
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[Primes Race (Mathematica Efficiency)] http://mathematica.stackexchange.com/questions/108798/primes-race-mathematica-efficiency
I am currently working with a paper that deals with this concept of Prime Races. You essentially create a large list of prime numbers and then split that list into two teams. You are assigned to ...
- asked by Dops (10 votes), answered by bbgodfrey (6 votes)
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[Gathering of list] http://mathematica.stackexchange.com/questions/109104/gathering-of-list
Problem statement
The following challenge was recently posted to the J language programming forum by Skip Cave http://jsoftware.com/pipermail/programming/2016-March/044561.html
"The animal ...
- asked by murray (9 votes), answered by J. M. (13 votes)
================================== Greatest hits from previous weeks: ==================================
[Find eigen energies of time-independent Schrodinger equation] http://mathematica.stackexchange.com/questions/32293/find-eigen-energies-of-time-independent-schr%c3%b6dinger-equation
I’m trying to get the eigenvalues of a one dimensional time-independent Schrodinger equation,
\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)
where U(x) is some potential and Ei is the ...
- asked by xslittlegrass (35 votes), answered by Jens (38 votes)
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[How to plot an ellipse?] http://mathematica.stackexchange.com/questions/20100/how-to-plot-an-ellipse
I’m new to Mathematica, and I’m finding it difficult to plot an ellipse. I tried using
Plot[(x/5)^2 + (y/3)^2 == 1, {x, -5, 5}, {y, -3, 3}]
but I’m getting some errors. Is there something wrong ...
- asked by Sriram (4 votes), answered by Jens (12 votes)
================================== Can you answer these? ==================================
[Mimicking Console and Output Matlab/Rstudio-Style Environment in Mathematica?] http://mathematica.stackexchange.com/questions/109179/mimicking-console-and-output-matlab-rstudio-style-environment-in-mathematica
I am trying to crudely approximate the RStudio or Matlab Workspace environment in Mathematica by having a specific notebook function as the "console notebook" where I execute commands and another ...
- asked by user13999 (6 votes)
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[What is the equivalent of $ModuleNumber for DynamicModule] http://mathematica.stackexchange.com/questions/108850/what-is-the-equivalent-of-modulenumber-for-dynamicmodule
Mathematica provides access to $ModuleNumber which can be enormously useful.
Unfortunately I can’t find the equivalent for DynamicModule.
I know such a parameter must exist for two reasons:
First, ...
- asked by MB1965 (8 votes)
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[Why this expression is not evaluated correctly?] http://mathematica.stackexchange.com/questions/109310/why-this-expression-is-not-evaluated-correctly
Look at the following code:
f[kx_, ky_] := -1*(Exp[I*kx] + 2*Exp[-I*kx/2]*Cos[Sqrt[3]*ky/2]); H = {{1, f[kx, ky]}, {Conjugate[f[kx, ky]], -1}}; D[Norm[Normalize[Eigensystem[H][[2]][[1]]]], kx] /. {kx ...
- asked by Chong Wang (1 vote)
================================== Top new questions this week: ==================================
[Typoglycemia text manipulation] http://mathematica.stackexchange.com/questions/108563/typoglycemia-text-manipulation
I was just reading the article: https://en.wikipedia.org/wiki/Typoglycemia
"... readers can understand the meaning of words in a sentence even when the interior letters of each word are scrambled ...
- asked by mrz (20 votes), answered by J. M. (15 votes)
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[Version inconsistency with optional arguments: what if the default value doesn’t match the pattern?] http://mathematica.stackexchange.com/questions/108636/version-inconsistency-with-optional-arguments-what-if-the-default-value-doesnt
I just came across some weird behaviour. Take this function definition:
ClearAll[f] f[vs_List : All] := "match"
The default value of vs is All. Now think about what f[] should return. Should it ...
- asked by Szabolcs (18 votes), answered by Mr.Wizard (12 votes)
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[Reproducing a ranking function that behaves like Excel’s RANK] http://mathematica.stackexchange.com/questions/108309/reproducing-a-ranking-function-that-behaves-like-excels-rank
I tried to find a function or expression in Mathematica that produces the same output as the RANK function in Excel (see its description here), but unfortunately I could not find an existing one.
For ...
- asked by M.Basel (14 votes), answered by TomD (18 votes)
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[Given a large binary matrix, find the largest submatrix containing non-zero elements] http://mathematica.stackexchange.com/questions/108299/given-a-large-binary-matrix-find-the-largest-submatrix-containing-non-zero-elem
I’m looking for a way to reduce a binary matrix containing zeros at some positions into a matrix that contains no zeros by deleting rows and columns of the original matrix until only non-zero values ...
- asked by tavr (13 votes), answered by unlikely (4 votes)
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[Generating a list of numbers that are not multiples of 4] http://mathematica.stackexchange.com/questions/108502/generating-a-list-of-numbers-that-are-not-multiples-of-4
I want to write simple code that will list all numbers from \(1\) to \(n\) that are not multiples of \(4\).
And in this case I consider that
n=100 For[i = 1, i <= n, i++, If[Mod[i, 4] != 0, ...
- asked by Mariam (12 votes), answered by Mr.Wizard (15 votes)
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[Can Mathematica convert a RegularExpression into a StringExpression or vice-versa?] http://mathematica.stackexchange.com/questions/108481/can-mathematica-convert-a-regularexpression-into-a-stringexpression-or-vice-vers
I know that Mathematica can perform string comparison using either StringExpression or RegularExpression. Although regular expressions are more common, I feel that the Mathematica StringExpressions ...
- asked by Denis Cousineau (12 votes)
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[What options and settings can be used to create print quality typeset documents with Mathematica?] http://mathematica.stackexchange.com/questions/108553/what-options-and-settings-can-be-used-to-create-print-quality-typeset-documents
If I am proficient on dedicated typesetting software (e.g. LaTeX) it makes sense to use that for typesetting but if I am not how can I use Mathematica to create good quality documents.
The question ...
- asked by Mike Honeychurch (11 votes), answered by Mike Honeychurch (17 votes)
================================== Greatest hits from previous weeks: ==================================
[1 Plot, 2 Scale/Axis] http://mathematica.stackexchange.com/questions/627/1-plot-2-scale-axis
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
- asked by 500 (97 votes), answered by ArgentoSapiens (92 votes)
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[Generating a Sierpinski carpet] http://mathematica.stackexchange.com/questions/22052/generating-a-sierpinski-carpet
I am trying to draw a Sierpinski_carpet. I have code that works, but I think there is a more elegant way to do than my way. Maybe I couls use Tuples or Permutations or some similar function to ...
- asked by chyaong (43 votes), answered by Mr.Wizard (66 votes)
================================== Can you answer these? ==================================
[Prepending a sequence with zeros gives ‘FindGeneratingFunction‘ hard time] http://mathematica.stackexchange.com/questions/108451/prepending-a-sequence-with-zeros-gives-findgeneratingfunction-hard-time
Asking for
FindGeneratingFunction[{1, 3, 11, 43, 171, 683, 2731, 10923, 43691, 174763}, t] gives the answer (namely (1 - 2 t)/(1 - 5 t + 4 t^2)) almost immediately. However if I prepend zeros in ...
- asked by (3 votes)
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[Obtaining a Previously Constructed Function as Desired Output] http://mathematica.stackexchange.com/questions/108373/obtaining-a-previously-constructed-function-as-desired-output
I was playing around with some Generalized Trigonometric Functions defined as follows;
w[n_] := E^((2*\[Pi]*I)/n) Ncos[n_, x_] := Expand[(1/n)*Sum[E^(x*w[2 n]^(2 k + 1)), {k, 0, n - 1}]]
...
- asked by Eleven-Eleven (3 votes)
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[The implementation of FunctionRange] http://mathematica.stackexchange.com/questions/108308/the-implementation-of-functionrange
How exactly does the FunctionRange work? What kind of algorithm does it use? I looked it up in the manual but it doesn’t provide any references or even a name of the algorithm.
It also accepts a ...
- asked by pwl (3 votes)
================================== Top new questions this week: ==================================
[++ is dangerous for C programmers] http://mathematica.stackexchange.com/questions/107619/is-dangerous-for-c-programmers
I noticed this fact, that may be misleading for programmers used to C language.
In Mathematica, if you have a function f[] and an array v, and you write
v[[ f[] ]]++
the function f is called ...
- asked by Giovanni Resta (30 votes), answered by Mr.Wizard (23 votes)
[Apply multiple functions to same list] http://mathematica.stackexchange.com/questions/107721/apply-multiple-functions-to-same-list
I’d like to get the Min, Max, Median, Mean, etc. for the same list. For now I’m doing the following:
y = {1, 2, 3, 4, 5, 6, 7}; Map[{Max[#] , Min[#] , Median[#], Mean[#]} &, y, {0}]
It seems ...
- asked by Mitchell Kaplan (15 votes), answered by Bob Hanlon (18 votes)
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[How do I delete all items that occur more than once?] http://mathematica.stackexchange.com/questions/107483/how-do-i-delete-all-items-that-occur-more-than-once
DeleteDuplicates works fine but leaves a single copy of the duplicated item. I need to remove all items that occur more than once i.e. {{1,2},{1,2},{3,4}} -> {3,4}. There must be a one-liner.
- asked by Boris (12 votes), answered by Leonid Shifrin (16 votes)
[Puzzle with Mathematica] http://mathematica.stackexchange.com/questions/107859/puzzle-with-mathematica
Hello everyone, This is a puzzle I got from someone via social media. Basically, we need to fill up the boxes with the numbers 1-9 (no repetitions) that fit the multiplication and addition ...
- asked by iFikr (11 votes), answered by unlikely (13 votes)
[Finite Element Method and ElementMeshInterpolation issue in v10.3] http://mathematica.stackexchange.com/questions/107668/finite-element-method-and-elementmeshinterpolation-issue-in-v10-3
I recently installed Mathematica v10.3 and checked a project I was working on few months ago under Mathematica v10.1.
In this project I solve a PDE with NDSolve and Finite Element Method over a 2D ...
- asked by unlikely (10 votes), answered by Jason B (8 votes)
[Efficient way to make subsets of list with placeholders] http://mathematica.stackexchange.com/questions/107517/efficient-way-to-make-subsets-of-list-with-placeholders
I have an arbitrary list of unique elements:
lst = {a, b, c, d} Documentation allows finding subsets with same number of elements, say 2: Subsets[lst, {2}] (* {{a, b}, {a, c}, {a, d}, {b, c}, {b, ...
- asked by garej (10 votes), answered by Dr. belisarius (10 votes)
[Double Sum Involving Condition] http://mathematica.stackexchange.com/questions/107652/double-sum-involving-condition
I would like to compute the dimensions of some small free nilpotent Lie algebras. However, I am totally new to this and I could not figure out how to write the double sum which gives the dimension of ...
- asked by Can Hatipoglu (9 votes), answered by J. M. (13 votes)
================================== Greatest hits from previous weeks: ==================================
[Why round to even integers?] http://mathematica.stackexchange.com/questions/2116/why-round-to-even-integers
According to the Mathematica help: Round rounds numbers of the form x.5 toward the nearest even integer.
For example:
Round[0.5, 1.5, 2.5, 3.5, 4.5]
gives
0, 2, 2, 4, 4
What’s the ...
- asked by wxffles (42 votes), answered by Per Alexandersson (27 votes)
[Calling Correct Function for Plotting DiracDelta] http://mathematica.stackexchange.com/questions/3506/calling-correct-function-for-plotting-diracdelta
I am wondering what is the correct function in Mathematica to plot the true impulse function, better known as the DiracDelta[] function. When using this inside of a function or just the function ...
- asked by night owl (11 votes), answered by Heike (13 votes)
================================== Can you answer these? ==================================
[How many clusters does DominantColors return?] http://mathematica.stackexchange.com/questions/107842/how-many-clusters-does-dominantcolors-return
Is there any documentation on how it automatically chooses the number of colors - does it use X-means?
- asked by M.R. (3 votes)
[Using GNU Make to compile MathLink program automatically removes a file] http://mathematica.stackexchange.com/questions/107863/using-gnu-make-to-compile-mathlink-program-automatically-removes-a-file
It’s possible that this question belongs on Stackoverflow; however, the Mathematica context may be important so I’m asking here first.
I am working on a project to interact with sensors connected to ...
- asked by bobthechemist (1 vote)
[Why does Solve work in v9.0.1 but not in v10.3.1] http://mathematica.stackexchange.com/questions/107585/why-does-solve-work-in-v9-0-1-but-not-in-v10-3-1
I want to solve the following DE \[ P'=k(M-P)P, P[0]=53.08, P[50]=23.192, P[100]=76.212.\] The Mathematica command is
sol1 = DSolve[P'[t] == k (M - P[t]) P[t], P[t], t] P[t_] = sol1[[1,1,2]]
sol2 ...
- asked by xpaul (4 votes)
================================== Top new questions this week: ==================================
[Why does Mathematica report that \(\int _1^\infty \frac {\sin (\sqrt {x})}{\sqrt {x}}dx\) = \(2\cos (1)\)?] http://mathematica.stackexchange.com/questions/106162/why-does-mathematica-report-that-int-1-infty-frac-sin-sqrtx-sqrtxdx
Bug introduced in 7.0 or earlier and persisting through 10.3.1 or later
Mathematica 10 gives the following very odd result,
Integrate[Sin[Sqrt[x]]/Sqrt[x], {x, 1, Infinity}] (* 2 Cos[1] *)
which seems ...
- asked by JEM (30 votes)
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[How was Mathematica built?] http://mathematica.stackexchange.com/questions/106020/how-was-mathematica-built
I’ve been wondering this for a while now: How was Mathematica built?
Is it written in Haskell? C++? I’d love to get a taste of the wizardry behind this incredible software.
- asked by Chet (14 votes), answered by Sjoerd C. de Vries (19 votes)
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[How can one manually change the rule ordering] http://mathematica.stackexchange.com/questions/106068/how-can-one-manually-change-the-rule-ordering
I have a function which has some general behaviour, but that should act on some specific kinds of objects in some other way. I know that Mathematica is supposed to automatically order the rules so ...
- asked by Lior Blech (14 votes), answered by Mr.Wizard (15 votes)
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[What governs images resizing in the FrontEnd environment] http://mathematica.stackexchange.com/questions/106204/what-governs-images-resizing-in-the-frontend-environment
What is responsible for the middle Row images’ size? And why single image row is different?
{#, Row[{#, #}], Row[{#}]} & @ RandomImage[1, {100, 100}]
I know I can prevent that with mapping ...
- asked by Kuba (13 votes), answered by Jason B (9 votes)
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[How to report a bug in Mathematica] http://mathematica.stackexchange.com/questions/106227/how-to-report-a-bug-in-mathematica
I found two bugs in Mathematica (10.3 and 10.1) and I need to report it. Is there any tools to do that or section on Wolfram website?
- asked by Developer2000 (12 votes), answered by Szabolcs (17 votes)
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[Reproduce image effect in Mathematica] http://mathematica.stackexchange.com/questions/106165/reproduce-image-effect-in-mathematica
How do I create the "dotifying" effect below in Mathematica?
I have tried to use Rasterize first to get the image pixelated, but how do I get the disc/circle pattern then?
image := ...
- asked by macurie (12 votes), answered by rhermans (17 votes)
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[How to make a CahnHilliard model GIF] http://mathematica.stackexchange.com/questions/106333/how-to-make-a-cahn-hilliard-model-gif
The question derived from @Jason B ’s answer.I wanna make it but don’t how to do. But we can get some rule about the GIF
The change of the total pixel is very small.
imagelist = ...
- asked by yode (10 votes), answered by MarcoB (15 votes)
================================== Greatest hits from previous weeks: ==================================
[Generating visually pleasing circle packs] http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs
EDIT: (my conclusion and thank you note) I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you had fun and enjoyed it the same as I did.
I would like to ...
- asked by VividD (89 votes), answered by level1807 (53 votes)
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[How to calculate contour integrals with Mathematica?] http://mathematica.stackexchange.com/questions/34073/how-to-calculate-contour-integrals-with-mathematica
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
- asked by user64494 (20 votes), answered by Artes (39 votes)
================================== Can you answer these? ==================================
[Extracting control points from BezierFunction] http://mathematica.stackexchange.com/questions/107435/extracting-control-points-from-bezierfunction
given a Bezier surface, is there a simple way to express \(g_{12}\) (from the First fundamental form) again in Bezier form?
More precisely, I have control points and a Bezier function \(f\):
cps = {{{0, ...
- asked by Osmihran (1 vote)
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[Order of importing data from files] http://mathematica.stackexchange.com/questions/106296/order-of-importing-data-from-files
I have many text files numbered from 1 to 1 million in numerical order. Within each text file is 5 columns of data (TAB spaced) with many rows. I effectively want to take the minimum value from each ...
- asked by David (1 vote)
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[WolframScript Unix - Script Parameters on Raspberry Pi] http://mathematica.stackexchange.com/questions/107436/wolframscript-unix-script-parameters-on-raspberry-pi
I’m currently trying to run a script with 2 parameters which gets called via a BASH script. The script runs fine however the list of passed parameters , $ScriptCommandLine, always stays empty.
...
- asked by TheCheatsrichter (2 votes)
================================== Top new questions this week: ==================================
[Partitioning a list when the cumulative sum exceeds 1] http://mathematica.stackexchange.com/questions/105792/partitioning-a-list-when-the-cumulative-sum-exceeds-1
I have a long list of say 1 million Uniform(0,1) random numbers, such as:
dat = {0.71, 0.685, 0.16, 0.82, 0.73, 0.44, 0.89, 0.02, 0.47, 0.65}
I want to partition this list whenever the cumulative ...
- asked by wolfies (15 votes), answered by Mr.Wizard (18 votes)
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[How to extract a contour line (or a region) from a ContourPlot?] http://mathematica.stackexchange.com/questions/105750/how-to-extract-a-contour-line-or-a-region-from-a-contourplot
Given a ContourPlot with a set of contours, say, this:
is it possible to get the contours separating domains with the different colors in the form of lists?
For example, how to extract the ...
- asked by Alexei Boulbitch (12 votes), answered by Michael E2 (7 votes)
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[Using NDSolve to find particle trajectory] http://mathematica.stackexchange.com/questions/105859/using-ndsolve-to-find-particle-trajectory
I’m trying to simulate a particle in an electric and magnetic fields, but numerically instead of analytically. This is basically solving the equation
\[q \cdot \left (p'\times B\right ) + q\cdot E = m \]
- asked by triplebig (11 votes), answered by Sjoerd C. de Vries (11 votes)
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[why MatchQ is fast and Replace slow?] http://mathematica.stackexchange.com/questions/105626/why-matchq-is-fast-and-replace-slow
Consider a large expression, say a polynomial with 25 terms
expr=Product[Unique["a"],{i,1,25}];
to which you apply the following replacement rule:
rep={x_ f[y_] /; FreeQ[x, y] -> 0};
Since f ...
- asked by M. Tissier (11 votes), answered by Mr.Wizard (13 votes)
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[Use of some functions of the Developer Utility Package, such as BesselSimplify] http://mathematica.stackexchange.com/questions/105643/use-of-some-functions-of-the-developer-utility-package-such-as-besselsimplify
The Developer Utilities Package contains several functions that look interesting:
BesselSimplify GammaSimplify PolyGammaSimplify ZetaSimplify PolyLogSimplify and TrigToRadicals
However for each ...
- asked by Alexei Boulbitch (10 votes), answered by Jens (5 votes)
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[Plot of \(sin(x^x)\) is missing from \(x=143\)] http://mathematica.stackexchange.com/questions/105774/plot-of-sinxx-is-missing-from-x-143
When plotting the graph of \(\sin (x^x)\) I noticed that there is no plot from about \(x=143\). I don’t suppose there is a purely mathematical explanation for this?
So, why is there no graph in ...
- asked by Imre Vegh (10 votes), answered by MarcoB (22 votes)
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[Brackets around each item in matrix] http://mathematica.stackexchange.com/questions/105864/brackets-around-each-item-in-matrix
I have a matrix where every item in the matrix has its own brackets that I do not want. How can I remove the brackets around each item?
- asked by C. Tamaro (8 votes), answered by John Conor Cosnett (9 votes)
================================== Greatest hits from previous weeks: ==================================
[How do I clear all user defined symbols?] http://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation ->
Quit kernel and firing a
new one up?
- asked by niklasfi (37 votes), answered by Artes (31 votes)
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[Drawing a square root spiral] http://mathematica.stackexchange.com/questions/66969/drawing-a-square-root-spiral
Here is a start. I’m looking for a nice way to draw it.
Graphics[{EdgeForm[Black], White, Polygon @ {{0, 0}, {-1, 0}, Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, Polygon @ {{0, ...
- asked by mathe (22 votes), answered by Bob Hanlon (17 votes)
================================== Can you answer these? ==================================
[Weird behaviour for a vector InterpolatingFunction inside an NDSolve] http://mathematica.stackexchange.com/questions/105594/weird-behaviour-for-a-vector-interpolatingfunction-inside-an-ndsolve
I have run into some weird behaviour on the part of NDSolve which I find pretty bizarre and which I would like to understand better.
Suppose, for the sake of argument, that I want to study the ODE ...
- asked by Emilio Pisanty (3 votes)
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[NDeigensystem returns error due to mesh discretization when calculating vibrations of a cantilever] http://mathematica.stackexchange.com/questions/105840/ndeigensystem-returns-error-due-to-mesh-discretization-when-calculating-vibratio
There was an transcription error in the code I provided in a previous post:
NDeigensystem returns complex non-hermitian error for the calculation of vibrations of a cantilever
This resulted in it ...
- asked by user37299 (2 votes)
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[WhenEvent and Resetting of Variable in PDE when operation succeeds] http://mathematica.stackexchange.com/questions/105781/whenevent-and-resetting-of-variable-in-pde-when-operation-succeeds
I have had success in using WhenEvent to reset or change a variable within NDSolve with ordinary differential equations. My working, functioning MWE is:
Clear[usol, u, t, x, \[Lambda]] usol = NDSolveValue[ ...
- asked by drN (3 votes)
================================== Top new questions this week: ==================================
[Exponential fitting - isn’t actually a BUG there?] http://mathematica.stackexchange.com/questions/105002/exponential-fitting-isnt-actually-a-bug-there
There are many questions on this site about wrong exponential fitting in Mathematica but no one considers this well-known problem as a potential bug. Usually people suggest well-known workarounds ...
- asked by Alexey Popkov (20 votes), answered by Sjoerd C. de Vries (6 votes)
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[Detecting components in timeseries] http://mathematica.stackexchange.com/questions/104950/detecting-components-in-timeseries
I’m looking at this sequence of values:
I’d like to detect the points where the center of the time-series shifts (around x=1000 and x=2000). Many of the transforms and smoothing methods I have ...
- asked by M.R. (17 votes), answered by blochwave (22 votes)
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[Generating Tuples with restrictions] http://mathematica.stackexchange.com/questions/105139/generating-tuples-with-restrictions
I am interested in a certain subset of all tuples. Generating all with Tuples and then filtering is wasteful, and will "blow up" very quickly.
For a concrete example, let’s say I want to find all ...
- asked by Kiro (13 votes), answered by Kuba (12 votes)
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[Grid cuts my images] http://mathematica.stackexchange.com/questions/105061/grid-cuts-my-images
Bug introduced in V9.0 or earlier
and persisting through V10.3.1 or later
pic2 = ImageResize[ ImageCrop@Rasterize@Graphics@Disk[], {Automatic, 40}] Grid[{{pic2}}]
This is just ...
- asked by Kuba (11 votes), answered by Coolwater (7 votes)
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[Non Standard Eigenfunction Plots of the Laplacian Over the Unit Square] http://mathematica.stackexchange.com/questions/105264/non-standard-eigenfunction-plots-of-the-laplacian-over-the-unit-square
I have recently been plotting eigenfunctions of the laplacian over the unit square using the NDEigensystem command. However, I have noticed something in the plots which puzzles me.
Below is an image ...
- asked by Mr S 100 (11 votes), answered by Jens (12 votes)
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[How to count the number of the tube] http://mathematica.stackexchange.com/questions/105229/how-to-count-the-number-of-the-tube
There is a picture Get the binary image
binimg = ColorSeparate[img][[2]] // Binarize[#, 0.25] & // Thinning Visulize the result of regconization lines = ImageLines[binimg, 0.074]; ...
- asked by yode (11 votes), answered by nikie (7 votes)
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[Detecting X or O in a small image] http://mathematica.stackexchange.com/questions/105327/detecting-x-or-o-in-a-small-image
I am making a robot that plays Tic Tac Toe
Currently, I have code that will parse the board and separate it into an array of 9 images, each space on the board. How can I detect if the image ...
- asked by Jenny (10 votes), answered by John Conor Cosnett (17 votes)
================================== Greatest hits from previous weeks: ==================================
[Is there a syntax for single-line comments for notebooks?] http://mathematica.stackexchange.com/questions/1496/is-there-a-syntax-for-single-line-comments-for-notebooks
I’m aware that I can use (* ... *) to comment out stuff in a notebook. Many languages have a syntax for single-line comments, such as
// in C, C++, Java, C#, ... # in shell, Python, ...
For ...
- asked by Peeter Joot (37 votes), answered by Szabolcs (43 votes)
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[Advice for Mathematica as Mathematician’s Aid] http://mathematica.stackexchange.com/questions/92686/advice-for-mathematica-as-mathematicians-aid
I use Mathematica mainly as an aid in symbolic attacks on problems, usually intermediate or harder and often number theoretic. While Reduce, Simplify, et al. are remarkably powerful, they of course ...
- asked by CarlEdman (56 votes), answered by MarcoB (39 votes)
================================== Can you answer these? ==================================
[What are the time and space complexities of Classify/Predict?] http://mathematica.stackexchange.com/questions/105366/what-are-the-time-and-space-complexities-of-classify-predict
Does anyone have knowledge of the O(n) time and space complexities for various model types supported by Classify[] and Predict[] during training and evaluation?
Here are a list of supported model ...
- asked by M.R. (4 votes)
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[Finding eigenvalues in Mathematica: why so slow?] http://mathematica.stackexchange.com/questions/105224/finding-eigenvalues-in-mathematica-why-so-slow
I am trying to find the eigensystem of a large sparse real symmetric matrix, and I only need the lowest 40 or so eigenstates. The relevant code is as follows:
TheModel[V0_, V1_, V2_, index_, ...
- asked by Xiao (3 votes)
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[Notebook created in cloud has odd errors in Mathematica 10.3.1] http://mathematica.stackexchange.com/questions/105019/notebook-created-in-cloud-has-odd-errors-in-mathematica-10-3-1
I’ve downloaded a notebook from develop.wolframcloud.com and opened it in 10.3.1 (running on Win 10). When I evaluate some cells I get syntax errors along the lines of...
Syntax::sntxf: "\"Clear[\" ...
- asked by Ymareth (2 votes)
================================== Top new questions this week: ==================================
[List of Mathematica related acronyms and their real meaning] http://mathematica.stackexchange.com/questions/104593/list-of-mathematica-related-acronyms-and-their-real-meaning
A few years ago, Wolfram Inc. not only started to rename things around Mathematica, a lot of new technologies and frameworks were introduced as well. Now, we are left with a lot of acronyms and ...
- asked by halirutan (37 votes), answered by halirutan (38 votes)
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[What would you ask Mathematica to do on a big system?] http://mathematica.stackexchange.com/questions/104842/what-would-you-ask-mathematica-to-do-on-a-big-system
Our hardware supplier has given us the opportunity to test Mathematica on a big Windows system. The specs will be 1 to 4 TB of working memory and 12 sockets with 18 cores each. I got 1 full week of ...
- asked by pvanbijnen (25 votes), answered by David G. Stork (9 votes)
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[What algorithm do the Compress and Uncompress functions use?] http://mathematica.stackexchange.com/questions/104660/what-algorithm-do-the-compress-and-uncompress-functions-use
Compress and Uncompress are used internally by Mathematica to compress things like 3D data in notebook files - data that I’d like to read independently. Does anyone have any idea if the compression ...
- asked by Andy C. (12 votes), answered by Mark Adler (13 votes)
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[Is there any predictor-corrector method in Mathematica for solving nonlinear system of algebraic equations?] http://mathematica.stackexchange.com/questions/104578/is-there-any-predictor-corrector-method-in-mathematica-for-solving-nonlinear-sys
The FindRoot Function in Matheatica can easily be used to solve systems of nonlinear algebraic equations. But, I want to solve a system of nonlinear equations with variations of some parameters.
...
- asked by hesam (12 votes), answered by Chris K (9 votes)
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[How do I define a periodic region?] http://mathematica.stackexchange.com/questions/104723/how-do-i-define-a-periodic-region
I’m trying to create a region of "thick" grid-lines, like so
GRID = ImplicitRegion[((0 <= x <= 1 || 2 <= x <= 3 || 4 <= x <= 5 || 6 <= x <= 7 || 8 <= x <= 9) || (0 ...
- asked by Zorngo (12 votes), answered by Kuba (10 votes)
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[Zoom in on a 2D graph] http://mathematica.stackexchange.com/questions/104718/zoom-in-on-a-2d-graph
I have seen many queries on zooming in on plots etc. But I haven’t seen any regarding 2D graphs. For eg if I have a graph like
Graph[{1->2, 2->3, 3->1}].
It will create a graph. I have a ...
- asked by vikram reddy (10 votes), answered by Kuba (11 votes)
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[Fitting a curve to an image object: not a superellipse, not an egg curve.. what else?] http://mathematica.stackexchange.com/questions/104419/fitting-a-curve-to-an-image-object-not-a-superellipse-not-an-egg-curve-what
I’m facing the problem of quantifying the morphology of objects with such a shape (nannoconids...
they are fossils).
One of the final goals is to produce a solid of revolution and compute ...
- asked by Stefano (9 votes), answered by nikie (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Drawing a square root spiral] http://mathematica.stackexchange.com/questions/66969/drawing-a-square-root-spiral
Here is a start. I’m looking for a nice way to draw it.
Graphics[{EdgeForm[Black], White, Polygon @ {{0, 0}, {-1, 0}, Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, Polygon @ {{0, ...
- asked by mathe (22 votes), answered by Bob Hanlon (17 votes)
—————————-
[Advice for Mathematica as Mathematician’s Aid] http://mathematica.stackexchange.com/questions/92686/advice-for-mathematica-as-mathematicians-aid
I use Mathematica mainly as an aid in symbolic attacks on problems, usually intermediate or harder and often number theoretic. While Reduce, Simplify, et al. are remarkably powerful, they of course ...
- asked by CarlEdman (56 votes), answered by MarcoB (39 votes)
================================== Can you answer these? ==================================
[Way to make contour labels on SliceContourPlot3D?] http://mathematica.stackexchange.com/questions/104590/way-to-make-contour-labels-on-slicecontourplot3d
SliceContourPlot3D doesn’t seem to come with the option of putting contour labels on the plots as far as I can see. I’m using the XStackedPlanes option. I don’t see any information about how one might ...
- asked by Eli Morris (4 votes)
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[Implementation of a matrix formula] http://mathematica.stackexchange.com/questions/104463/implementation-of-a-matrix-formula
For the Bezier surface, which owns the following matrix definition:
where, \(B_{n,i}\) denotes Bernstein-basis.
vec1 = {B[0],...,B[m]}; mat = {{P[0,0],...P[0,n]},...,{P[m,0],...P[m,n]}}; vec2= ...
- asked by Shutao TANG (2 votes)
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[Can one preserve the appearance of the HorizontalGauge?] http://mathematica.stackexchange.com/questions/104524/can-one-preserve-the-appearance-of-the-horizontalgauge
I use sometimes the HorizontalGauge instead of a slider in Manipulateor instead of the ProgressIndicator. I find it very convenient, since it gives quantitative information on the status of the ...
- asked by Alexei Boulbitch (3 votes)
================================== Top new questions this week: ==================================
[Partition a list based on specific elements? Grab the sublists beginning with a certain marker elements] http://mathematica.stackexchange.com/questions/104153/partition-a-list-based-on-specific-elements-grab-the-sublists-beginning-with-a
Say I have the list
{{a}, {0, 2, 5}, {5, 4, 1}, {a}, {1, 1, 0}, {1, 4, 2}, {3, 3, 0}, {a}, {3, 2, 0}, {1, 4, 1}}
I would like to make sublists of everything beginning with the a element till ...
- asked by Jason B (11 votes), answered by Kuba (14 votes)
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[Why does Outer sometimes return a packed array, and sometimes not?] http://mathematica.stackexchange.com/questions/104040/why-does-outer-sometimes-return-a-packed-array-and-sometimes-not
For example
In[342]:= test3 = Flatten[Outer[Plus, Range[1000], Range[1000]], 1]; // AbsoluteTiming Out[342]= {0.0198735, Null}
returns PackedArray (examined by Developer‘PackedArrayQ[test3] ...
- asked by matheorem (10 votes), answered by Mr.Wizard (7 votes)
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[Interpolation function way off] http://mathematica.stackexchange.com/questions/104037/interpolation-function-way-off
I have a simple list of data points to which I would like to fit an interpolation function. However, the results given by Interpolation[] gives an oscillating function which is not warranted by the ...
- asked by Philo (9 votes), answered by Szabolcs (14 votes)
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[How to deal with bad arguments when a function’s UpValues is a pure-function?] http://mathematica.stackexchange.com/questions/103952/how-to-deal-with-bad-arguments-when-a-functions-upvalues-is-a-pure-function
In practice, I needs to define the UpValues of a user-defined function. For instance, the operation of function like differential formula , expansion and so on.
Here, I will give a example that came ...
- asked by Shutao TANG (8 votes), answered by Mr.Wizard (2 votes)
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[Using Solve to solve the equation \(x^{1/3}=-1\)] http://mathematica.stackexchange.com/questions/104281/using-solve-to-solve-the-equation-x1-3-1
I am curious why this command returned no answers:
Solve[x^(1/3) == -1, x] Gives this output: (* {} *) I was able to get around the problem with this: Solve[Surd[x, 3] == -1, x] Which ...
- asked by David (8 votes), answered by Jens (13 votes)
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[How do you convert RGBColor to an HTML-style string?] http://mathematica.stackexchange.com/questions/103999/how-do-you-convert-rgbcolor-to-an-html-style-string
If I run some color processing function, like:
Blend[RGBColor /@ {"#DC4E00", "#000000", "#822250", "#FCC11B"}] I get back a RGBColor object: RGBColor[0.5901960784313726, 0.29901960784313725, ...
- asked by d8uv (8 votes), answered by d8uv (9 votes)
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[ReplaceAll behavior change from 10.2 to 10.3] http://mathematica.stackexchange.com/questions/104354/replaceall-behavior-change-from-10-2-to-10-3
Executing:
replace[res_] := res /. {a_Integer, b_Integer} :> (a + b); l1 = <|"respID" -> {1,2} , "key2" -> <|"key2" -> {2, 1}|>|>; l2 = {"respID" -> {1,2} , "key2" -> ...
- asked by Murta (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Drawing a square root spiral] http://mathematica.stackexchange.com/questions/66969/drawing-a-square-root-spiral
Here is a start. I’m looking for a nice way to draw it.
Graphics[{EdgeForm[Black], White, Polygon @ {{0, 0}, {-1, 0}, Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, Polygon @ {{0, ...
- asked by mathe (22 votes), answered by Bob Hanlon (16 votes)
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[Mathematica 10.0.x freezes in Initializing kernels] http://mathematica.stackexchange.com/questions/92931/mathematica-10-0-x-freezes-in-initializing-kernels
Bug caused by paclet update and fixed by paclet update.
I updated to Windows 10 and have been running Mathematica fine on it for over a month. For some reason, it has just stopped working. I don’t ...
- asked by mitcheljh (67 votes), answered by ilian (84 votes)
================================== Can you answer these? ==================================
[How to find and show a point value on the line?] http://mathematica.stackexchange.com/questions/104384/how-to-find-and-show-a-point-value-on-the-line
Manipulate[ Module[{eqns, f}, eqns = {y'[x] == aa3*y[x]^3 + aa2*y[x]^2 + aa1*y[x] + aa0[t] + bb[t]/y[x], y[0] == 15}; f = NDSolve[eqns, y, {x, 0, 1}][[1, 1, -1]]; Plot[f[x], {x, 0, ...
- asked by user37037 (1 vote)
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[Is it possible for librarylink function to be Listable like that in Compile?] http://mathematica.stackexchange.com/questions/104382/is-it-possible-for-librarylink-function-to-be-listable-like-that-in-compile
We know in Compile, there is an Option RuntimeAttributes ; Listable which can let the compiled function easily explore the power of thread parallelization.
So is it possible for a librarylink ...
- asked by matheorem (2 votes)
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[How could get all escape characters in Mathematica?] http://mathematica.stackexchange.com/questions/104299/how-could-get-all-escape-characters-in-mathematica
I am evaluating expression by using KernelLink.
But the kernel will be suspended endless when meets a invalid escape character.
a\abc, \[badEscape]
for example.
So I have to filter all the invalid ...
- asked by Michael (3 votes)
================================== Top new questions this week: ==================================
[Why is SatisfiabilityCount faster than SatisfiableQ?] http://mathematica.stackexchange.com/questions/103726/why-is-satisfiabilitycount-faster-than-satisfiableq
Consider the following (large) Boolean expression, which arose in a SAT problem. (The expression is not satisfiable.)
bigExpr = Import["http://pastebin.com/raw/gEgGQ26S"];
On my system (Mathematica ...
- asked by David Zhang (13 votes), answered by Adam Strzebonski (16 votes)
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[ReplaceAll with Associations instead of Rules] http://mathematica.stackexchange.com/questions/103497/replaceall-with-associations-instead-of-rules
I have just noticed that
x /. <|x -> 123|> evaluates to 123
In other words, the association seems to behave as a rule. I didn’t see any example or reference to this behavior in the ...
- asked by Gustavo Delfino (13 votes), answered by Edmund (4 votes)
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[Is it possible to Parallelize Select?] http://mathematica.stackexchange.com/questions/103548/is-it-possible-to-parallelize-select
Given a large list of elements, is it possible to improve Select by parallelizing?
An example: from a 10,000,000-element list of integers between 1 and 10, select all primes
rl = RandomInteger[10, ...
- asked by jjstankowicz (11 votes), answered by bbgodfrey (15 votes)
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[how to enforce a symmetric solution with fem?] http://mathematica.stackexchange.com/questions/103606/how-to-enforce-a-symmetric-solution-with-fem
I’m solving the laplace equation in a domain with holes, and I need to compute the integral of the gradient on the boundary of these holes.
For that I define a mesh and solve the laplace equation ...
- asked by tsuresuregusa (10 votes), answered by user21 (5 votes)
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[Best way to emulate MATLAB’s bsxfun using Map and similar functions] http://mathematica.stackexchange.com/questions/103527/best-way-to-emulate-matlabs-bsxfun-using-map-and-similar-functions
Given a matrix, we want to subtract the mean of each column, from all entries in that column. So given this matrix:
(mat = 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12) // MatrixForm
the mean ...
- asked by Nasser (10 votes), answered by Mike Honeychurch (11 votes)
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[Order of evaluation - does Mathematica evaluate variables before or after substitution?] http://mathematica.stackexchange.com/questions/103800/order-of-evaluation-does-mathematica-evaluate-variables-before-or-after-substi
Let’s say I write
y = x^2; x = 10; z = y + y^2 + y^3
Does Mathematica internally evaluate y before or after substituting it into z? I.e., does Mathematica internally evaluate this as
y = x^2 = ...
- asked by tparker (9 votes), answered by Alexei Boulbitch (12 votes)
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[How to "inform" successive ContourPlot calculations?] http://mathematica.stackexchange.com/questions/103673/how-to-inform-successive-contourplot-calculations
I need to draw some contour plots of very non-linear functions. As a simple example, take a Mandelbrot Set divergence contour near \(z\approx i\). (Just to be clear, I’m not trying to write a ...
- asked by Jerry Guern (9 votes), answered by bbgodfrey (10 votes)
================================== Greatest hits from previous weeks: ==================================
[How to calculate contour integrals with Mathematica?] http://mathematica.stackexchange.com/questions/34073/how-to-calculate-contour-integrals-with-mathematica
How to calculate the integral of \(\frac {1}{\sqrt {4 z^2 + 4 z + 3}}\) over the unit circle counterclockwise for each branch of the integrand?
- asked by user64494 (20 votes), answered by Artes (39 votes)
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[How do I remove grid from this photo?] http://mathematica.stackexchange.com/questions/88494/how-do-i-remove-grid-from-this-photo
I found this cat a month ago, and I’m not his owners’ friend so the mosquito grid was the inevitable problem. I would like to post-process this photo to get rid of it, but I don’t know exactly how ...
- asked by Nakilon (30 votes), answered by nikie (49 votes)
================================== Can you answer these? ==================================
[Fitting data with unique variable per measurement] http://mathematica.stackexchange.com/questions/103770/fitting-data-with-unique-variable-per-measurement
Imagine we are in the following situation, we have a nonlinear system of functions \(f\) with coordinates \(x_i\), and unknown parameters \(\delta _i\)’s and \(t\). Let this system be defined as,
...
- asked by user19218 (3 votes)
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[‘ParallelTable‘ pending the MathKernel after execution] http://mathematica.stackexchange.com/questions/103611/paralleltable-pending-the-mathkernel-after-execution
I have done a ParallelTable computation in script mode. After execution, the output is fine and I’ve got all the data I needed. but the kernel seems pending, usually it should exit after they finished ...
- asked by buzhidao (2 votes)
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[Call Magma in Mathematica] http://mathematica.stackexchange.com/questions/103602/call-magma-in-mathematica
I’ve written some code in Mathematica, related to some group theory questions I have. Subsequently, I found that part of the code could be significantly sped up if I could just call a routine in ...
- asked by Pace Nielsen (4 votes)
================================== Top new questions this week: ==================================
[Optional throws error when called from a package. Workaround?] http://mathematica.stackexchange.com/questions/103084/optional-throws-error-when-called-from-a-package-workaround
Bug introduced in 8.0 or earlier and persisting through 10.3 or later.
Case number: 305932.
In the front-end notebook (Mathematica 9.0 and 10.2):
g[x: Optional[_,default]]:=x;
has no problems, ...
- asked by QuantumDot (10 votes), answered by jkuczm (11 votes)
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[How to automatically have ContourLabels in middle of Contour lines if specific levels are not specified?] http://mathematica.stackexchange.com/questions/103289/how-to-automatically-have-contourlabels-in-middle-of-contour-lines-if-specific-l
I looked at all the questions/answers relating to placement of ContourLabels but could not find an answer to this. Some of the answers before are based on user giving before-hand, the Contours levels ...
- asked by Nasser (8 votes), answered by Jens (10 votes)
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[Generating assignments and transforming code inside Holding forms when generating code] http://mathematica.stackexchange.com/questions/103263/generating-assignments-and-transforming-code-inside-holding-forms-when-generatin
I have been playing with slightly above trivial code manipulations in Mathematica. I thought Mathematica would be great for this kind of work because of rule replacement and expression manipulation, ...
- asked by Manuel Odendahl (7 votes), answered by Leonid Shifrin (9 votes)
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[Overlay vs Show for plots?] http://mathematica.stackexchange.com/questions/103073/overlay-vs-show-for-plots
I am trying to understand the differences of Overlay and Show to combine two plots. A typical use case is to superpose a ListPlot of some data with a Plot of a curve to fit the data.
The following ...
- asked by becko (7 votes), answered by eldo (13 votes)
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[What should I learn from DSolve working better with a named constant than a number in this case?] http://mathematica.stackexchange.com/questions/103327/what-should-i-learn-from-dsolve-working-better-with-a-named-constant-than-a-numb
I have an equation \[\bigl (r''(\phi )r(\phi ) - r'(\phi )^2\bigr )\bigl (b + r(\phi )\bigr ) = r(\phi )\bigl (r'(\phi )^2 + r(\phi )^2\bigr )\] Here \(b\) and \(r\) are lengths, and \(\phi \) is an angle (in radians, so ...
- asked by David Z (7 votes), answered by bbgodfrey (2 votes)
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[W|A or Mathematica for CountryData?] http://mathematica.stackexchange.com/questions/103302/wa-or-mathematica-for-countrydata
Sometimes W|A gives you something ...
WolframAlpha["electricity production of the United States in 2007", "Result"] ... not available in the WDF CountryData["UnitedStates", ...
- asked by Ronald Monson (7 votes), answered by Paco Jain (3 votes)
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[How to implement JoinTo efficiently?] http://mathematica.stackexchange.com/questions/103238/how-to-implement-jointo-efficiently
AppendTo is not efficient so I’m not quite sure of the best way to implement its analogue for joining (e.g. in python this would be extend function). So how can this be improved:
ClearAll[JoinTo]; ...
- asked by M.R. (7 votes), answered by eldo (0 votes)
================================== Greatest hits from previous weeks: ==================================
[Find eigen energies of time-independent Schrodinger equation] http://mathematica.stackexchange.com/questions/32293/find-eigen-energies-of-time-independent-schrodinger-equation
I’m trying to get the eigenvalues of a one dimensional time-independent Schrodinger equation,
\(-\frac {h^2}{2m_0}\frac {d^2\psi }{dx^2}+U(x)~\psi =Ei~\psi \)
where U(x) is some potential and Ei is the ...
- asked by xslittlegrass (33 votes), answered by Jens (36 votes)
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[How to create word clouds?] http://mathematica.stackexchange.com/questions/2334/how-to-create-word-clouds
Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ...
- asked by Istvan Zachar (124 votes), answered by Heike (105 votes)
================================== Can you answer these? ==================================
[How can I import from a usb webcam on the raspberry pi?] http://mathematica.stackexchange.com/questions/103364/how-can-i-import-from-a-usb-webcam-on-the-raspberry-pi
I’m trying to set up a raspberry pi as a webcam server and I need to import images into a mathematica notebook on the raspberry pi. I tried using CurrentImage[] just to test it but I got an error just ...
- asked by Tobias Nash (2 votes)
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[How to change default font for all existing notebooks at once?] http://mathematica.stackexchange.com/questions/103053/how-to-change-default-font-for-all-existing-notebooks-at-once
By default, Mathematica 9 and 10 use Gill Sans MT fonts for headings of title/subtitle/section/subsection/subsubsection. Unfortunately, Gill Sans MT fonts have no Cyrillic letters, so that all ...
- asked by Igor Kotelnikov (5 votes)
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[VERY slow to solve a nonlinear equation involving matrix eigenvalues] http://mathematica.stackexchange.com/questions/103282/very-slow-to-solve-a-nonlinear-equation-involving-matrix-eigenvalues
I am trying to solve a problem similar to the following:
f[k_, a_] := ( Matrix = {{0.05, (a*k)^2}, {(a*k)^2, -0.05}}; {eps, psi} = Eigensystem[Matrix]; {eps,psi} = {eps[[#]], psi[[#]]} &@ ...
- asked by Xiao (2 votes)
================================== Top new questions this week: ==================================
[\(\sum _{k=1}^{\infty } \left \lfloor \frac {5}{5^k}\right \rfloor \) giving wrong answer?] http://mathematica.stackexchange.com/questions/102722/sum-k-1-infty-left-lfloor-frac55k-right-rfloor-giving-wrong-ans
When I try to evaluate the following:
\[\sum _{k=1}^{\infty } \Bigg \lfloor \frac {5}{5^k}\Bigg \rfloor \]
using
Sum[Floor[5/5^k], {k, 1, \[Infinity]}]
Mathematica provides an answer of \(0\) when it ...
- asked by 1110101001 (14 votes), answered by ttetrafon (-4 votes)
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[How do I insert a calculated value into a text cell?] http://mathematica.stackexchange.com/questions/102849/how-do-i-insert-a-calculated-value-into-a-text-cell
Suppose in a notebook I’ve calculated the value of some expression and assigned it to a variable. How do I insert the value of that variable in a text cell without just typing in the value? That is, I ...
- asked by Robert B (10 votes), answered by eldo (3 votes)
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[Prevent Plus from threading] http://mathematica.stackexchange.com/questions/102721/prevent-plus-from-threading
This is probably a very simple question, but I couldn’t find a duplicate.
As everybody knows, x, y + v gives x + v, y + v. But if I intend v to represent a vector, for example if I am going to ...
- asked by Rahul (10 votes), answered by JHM (5 votes)
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[What kind of patterns in a list of rules would benefit from being Dispatched?] http://mathematica.stackexchange.com/questions/102873/what-kind-of-patterns-in-a-list-of-rules-would-benefit-from-being-dispatched
I have a long list of rules for manipulating expressions. They are of the form:
complexRules = {f[x_, y_]^2 :> (*something*), f[x_, y_] f[x_, z_] :> (*something*), ...
- asked by QuantumDot (9 votes), answered by Schopenhauer (7 votes)
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[Revolution of Koch Snowflake] http://mathematica.stackexchange.com/questions/102697/revolution-of-koch-snowflake
How to plot shape which made from revolution of the Koch Snowflake?
I try to use \(RevolutionPlot3D[f,\lbrace {t,t_1} \rbrace ]\), but I think there is no \(f\) for Koch Snowflake.
Sorry for my ...
- asked by vito (9 votes), answered by ubpdqn (11 votes)
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[Reverse Polish Notation] http://mathematica.stackexchange.com/questions/102976/reverse-polish-notation
Is there a way to evaluate a string containing RPN in Mathematica?
SE thinks this question is too short, so let me expand on it. Do you know of any function, that provides the following ...
- asked by murphy (8 votes), answered by Mark Adler (4 votes)
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[Bug? Completely wrong results from NSolve] http://mathematica.stackexchange.com/questions/102724/bug-completely-wrong-results-from-nsolve
The following code creates two polynomials \(q_1\) and \(q_2\) in variables \(c\) and \(p\), then uses NSolve to find roots. But the polynomials don’t evaluate to zero at those roots.
pp[n_] := If[n > 0, ...
- asked by Jerry Guern (8 votes), answered by Rom38 (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Advice for Mathematica as Mathematician’s Aid] http://mathematica.stackexchange.com/questions/92686/advice-for-mathematica-as-mathematicians-aid
I use Mathematica mainly as an aid in symbolic attacks on problems, usually intermediate or harder and often number theoretic. While Reduce, Simplify, et al. are remarkably powerful, they of course ...
- asked by CarlEdman (55 votes), answered by MarcoB (39 votes)
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[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (386 votes), answered by faysou (354 votes)
================================== Can you answer these? ==================================
[CDF Enterprise : Protection and licensing] http://mathematica.stackexchange.com/questions/102650/cdf-enterprise-protection-and-licensing
I am new to Mathematica but on top of that I am asked to create a CDF file that is IP protected (encrypted) and also licensed.
In this video they are giving the way to protect the code. At the end ...
- asked by Erdem (3 votes)
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[Speedup ListCorrelation when using generalized correlation function] http://mathematica.stackexchange.com/questions/102708/speedup-listcorrelation-when-using-generalized-correlation-function
ImageCorrelation provides several general function that can be used to replace the default Dot function. For example, in the documentation of ImageCorrelation, there is an example using CosineDistance ...
- asked by xslittlegrass (1 vote)
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[How can I define geographic regions and new entities?] http://mathematica.stackexchange.com/questions/102948/how-can-i-define-geographic-regions-and-new-entities
There are three functions (GeoListPlot, GeoGraphics and Entity) related to working with geographic regions but it is not clear from the documentation how to create new Entities or custom geographic ...
- asked by Tyler Durden (4 votes)
================================== Top new questions this week: ==================================
[How to organically build up nested associations?] http://mathematica.stackexchange.com/questions/102466/how-to-organically-build-up-nested-associations
Suppose I want to construct an association of associations, such as a list of people with attributes:
peopleFacts=<| alice-> <|age->29,shoeSize->7|>, bob-> ...
- asked by Jess Riedel (17 votes), answered by Kuba (14 votes)
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[How to restart computation when kernels die?] http://mathematica.stackexchange.com/questions/102268/how-to-restart-computation-when-kernels-die
When an important process needs to be kept alive, there are monitoring tools to restart them if they die (e.g. god tasks in ruby), in my case I have an overnight scraping task that I need to have done ...
- asked by M.R. (15 votes), answered by Szabolcs (11 votes)
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[If I have a very large Popup Menu list how can I make that searchable?] http://mathematica.stackexchange.com/questions/102470/if-i-have-a-very-large-popup-menu-list-how-can-i-make-that-searchable
Imagine that you have a PopupMenu’s list that requires a lot of scrolling through the selections. Is there a way to create a control that will only display a subsection of the complete list?
- asked by Mike Honeychurch (14 votes), answered by Mike Honeychurch (14 votes)
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[Bug in RegionMember?] http://mathematica.stackexchange.com/questions/102439/bug-in-regionmember
RegionMember (new in V10) appears to have a bug. For some polygons it finds points that are clearly outside to be "members" of the region. This depends on the shape of the polygon in a way that is ...
- asked by kukako-muka (14 votes)
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[Which elements of a large array are part of a set?] http://mathematica.stackexchange.com/questions/102212/which-elements-of-a-large-array-are-part-of-a-set
I have a large integer packed array arr. My array is multidimensional, but for simplicity let’s consider 1D arrays for now. ArrayReshape takes care of the rest.
I also have a set of integers (a ...
- asked by Szabolcs (14 votes), answered by Leonid Shifrin (11 votes)
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[more numerically accurate inverse matrix] http://mathematica.stackexchange.com/questions/102261/more-numerically-accurate-inverse-matrix
I encountered the following matrix
mat = {{2, 2.161209223472559` + 1.682941969615793` I}, {2.161209223472559` - 1.682941969615793` I, 2}} and Inverse[mat] will give {{-0.57092 - ...
- asked by matheorem (12 votes), answered by Karsten 7. (11 votes)
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[Stress calculations using finite elements] http://mathematica.stackexchange.com/questions/102522/stress-calculations-using-finite-elements
A standard engineering problem is to calculate stresses in a structure due to applied forces. With the inclusion of the finite element method in version 10 this question attempts to investigate how ...
- asked by Hugh (11 votes), answered by user21 (2 votes)
================================== Greatest hits from previous weeks: ==================================
[Upgrade to Windows 10] http://mathematica.stackexchange.com/questions/89407/upgrade-to-windows-10
Can users of Mathematica on Windows 7 or Windows 8/8.1 upgrade their computers to Windows 10 a process that began today? Does Mathematica work? Are all the settings, licenses, access to files and ...
- asked by Lubos Motl (38 votes), answered by RunnyKine (32 votes)
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[How can I improve Mathematica’s resolution on a macbook retina display?] http://mathematica.stackexchange.com/questions/18419/how-can-i-improve-mathematicas-resolution-on-a-macbook-retina-display
Mathematica 9.0 looks a bit fuzzy on the retina screen, how can I increase the resolution?
Here another screenshot showing a direct comparison between the browser and Mathematica
- asked by Tom Wellington (39 votes), answered by programming_historian (20 votes)
================================== Can you answer these? ==================================
[How to avoid crashing with ConformImages?] http://mathematica.stackexchange.com/questions/102578/how-to-avoid-crashing-with-conformimages
ConformImages[] is causing a kernel crash when applied to a list of 5k images. Is there any way to apply ConformImages on the list in batches or asynchronously to conserve memory?
Here’s the ...
- asked by M.R. (2 votes)
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[Fitting real and imaginary parts of a function] http://mathematica.stackexchange.com/questions/102233/fitting-real-and-imaginary-parts-of-a-function
I have an analytic form of a function
G[w_] = -I*z0*w/(1 + I*z0*w*a)
I know this function can be obtained (up to some overall normalization) from solving a differential equation numerically for ...
- asked by Physics Moron (3 votes)
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[Reconstruct a ‘Graph‘ from a picture] http://mathematica.stackexchange.com/questions/102362/reconstruct-a-graph-from-a-picture
Actually,I post a very similar question before this.How to generate a Graph from a picture of a graph
The Dr. belisarius’s answer have accomplished it.But I find a limitation in that method:If the ...
- asked by yode (6 votes)
================================== Top new questions this week: ==================================
[How can I use Kenneth Moreland’s "Diverging Color Maps for Scientific Visualization" in plots?] http://mathematica.stackexchange.com/questions/101625/how-can-i-use-kenneth-morelands-diverging-color-maps-for-scientific-visualizat
I often want to plot two dimensional data that is centered around zero (for me, this is usually a 2D optical spectroscopy signal, but there are other cases), and the MATLAB "Jet" color scheme is ...
- asked by Jason B (21 votes), answered by Jason B (25 votes)
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[Named patterns in Except] http://mathematica.stackexchange.com/questions/101903/named-patterns-in-except
Bug introduced in 8 or earlier and persisting through 10.3 or later
Bug isn’t present in version 5.2
I don’t think I quite understand how Except works.
I want to define \(f(a,b) = (a-b)\ln (a-b)\), ...
- asked by QuantumDot (12 votes), answered by Kuba (11 votes)
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[What is the difference between Inherited and (Inherited + 0)] http://mathematica.stackexchange.com/questions/101715/what-is-the-difference-between-inherited-and-inherited-0
Let’s create a stylesheet:
NotebookPut@ Notebook[{ Cell[StyleData[StyleDefinitions -> "Default.nb"]], Cell[StyleData["myStyle"]], Cell[StyleData["myStyle2", StyleDefinitions -> ...
- asked by Kuba (12 votes), answered by Kuba (5 votes)
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[Why is DiscretizeGraphics missing points on my curve?] http://mathematica.stackexchange.com/questions/101594/why-is-discretizegraphics-missing-points-on-my-curve
I have a graphics expression which renders nicely as a closed curve when put in Graphics, I don’t understand why I can’t get the lines from DiscretizeGraphics or BoundaryDiscretizeGraphics:
p = ...
- asked by M.R. (12 votes), answered by Jason B (7 votes)
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[What’s going on here? Some kind of rationalization "under the covers"?] http://mathematica.stackexchange.com/questions/102050/whats-going-on-here-some-kind-of-rationalization-under-the-covers
Observe:
eq = (.25 a + .5 b + .25 c); CoefficientRules[eq^2] CoefficientRules[eq^2 // Expand] results in {{2, 0, 0} -> 1/16, {1, 1, 0} -> 1/4, {1, 0, 1} -> 1/8, {0, 2, 0} -> 1/4, ...
- asked by ciao (11 votes)
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[Integration of incomplete rings (ellipses) pattern] http://mathematica.stackexchange.com/questions/102069/integration-of-incomplete-rings-ellipses-pattern
I am facing a problem in trying to do a series of averages in incomplete images. I have a series of X-ray data images, like this one:
As you can see my image is a series of partial rings/ellipses ...
- asked by Matteo S (10 votes), answered by nikie (16 votes)
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[Is mathematica’s right click menu customizable to add Simplify tools?] http://mathematica.stackexchange.com/questions/101684/is-mathematicas-right-click-menu-customizable-to-add-simplify-tools
Mathematica provide Algebraic Manipulate palette for simplifying expression. But the palette window will always stay on top, which is quite annoying.
Is is possible to customize mathematica’s right ...
- asked by matheorem (10 votes), answered by Karsten 7. (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J. M. (382 votes), answered by faysou (348 votes)
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[How to make Jacobian automatically in Mathematica] http://mathematica.stackexchange.com/questions/5790/how-to-make-jacobian-automatically-in-mathematica
If we have two vectors, \(a\) and \(b\), how can I make Jacobian matrix automatically in Mathematica?
$$ a=\left( \begin{array}{c} x_1^3+2x_2^2 \\ 3x_1^4+7x_2 \end{array} \right);b=\left( $$
- asked by George Mills (20 votes), answered by Jens (27 votes)
================================== Can you answer these? ==================================
[Coppersmith’s algorithm like Pari’s zncoppersmith?] http://mathematica.stackexchange.com/questions/101978/coppersmiths-algorithm-like-paris-zncoppersmith
Is there some Mathematica package (or built-in that I missed) available, more or less equivalent to Pari’s zncoppersmith function?
Paraphrasing that source: given a polynomial \(P(x)\) with integer ...
- asked by fgrieu (1 vote)
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[How do I calculate this integral along a complex line (not a contour) in mathematica?] http://mathematica.stackexchange.com/questions/102088/how-do-i-calculate-this-integral-along-a-complex-line-not-a-contour-in-mathema
Given the function:
\[f(z) = \frac {\pi ^2 \cot (\pi \sqrt z) \cot (\pi \sqrt {z-a})}{4\sqrt {z^2 - az}}\]
Where a is a positive constant and:
$$z = \frac{i}{b} + t $$ $$t>a$$
Where b is also a ...
- asked by T. Welsh (1 vote)
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[How to add symbols to autocompletion list] http://mathematica.stackexchange.com/questions/101871/how-to-add-symbols-to-autocompletion-list
There are some built-in Mathematica symbols that I use quite frequently but are not included in the autocompletion list in the front end. Examples are Analytic and PolynomialForm. (As @march points ...
- asked by QuantumDot (4 votes)
================================== Top new questions this week: ==================================
[Can I emulate Wolfram’s automatic package updating in my own packages?] http://mathematica.stackexchange.com/questions/101035/can-i-emulate-wolframs-automatic-package-updating-in-my-own-packages
It seems that some Wolfram-provided packages are smart enough to automatically check with the Wolfram servers, notice when a newer version is available, and download it, so that the user always has ...
- asked by ibeatty (12 votes), answered by ZachB (3 votes)
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[Zooming using GeoGraphics] http://mathematica.stackexchange.com/questions/100920/zooming-using-geographics
Suppose I do:
GeoGraphics[Entity["City", "Eureka", "California", "UnitedStates"]]
What do folks do at this point to zoom in to various parts of the image?
- asked by David (12 votes), answered by Peter Roberge (12 votes)
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[Shortest tour with vertex priority] http://mathematica.stackexchange.com/questions/101175/shortest-tour-with-vertex-priority
I changed the title of my question and tried to simplify formulation of the problem.
I solve a very big vehicle routing problem. I divided this one big problem on many small sub-problems. Each small ...
- asked by Alexey Golyshev (10 votes), answered by Alexey Golyshev (4 votes)
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[Backquote in string template?] http://mathematica.stackexchange.com/questions/101342/backquote-in-string-template
I need to have backquotes in a StringTemplate. For example StringTemplate["``1``"][2] Returns "21" instead of "`2`". How can I get the correct result ? Of course a solution would be to use ...
- asked by faysou (8 votes), answered by Kuba (5 votes)
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[create an (almost) hexagonal mesh on an ellipsoid] http://mathematica.stackexchange.com/questions/101183/create-an-almost-hexagonal-mesh-on-an-ellipsoid
EDIT I edited the question in order to take into @Kuba’s comment.
I want to create this figure with Mathematica (in particular an almost hexagonal mesh on an ellipsoid; thanks to @Kuba I know this ...
- asked by dimitris (8 votes), answered by Kuba (10 votes)
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[How to count number of small dots in a picture] http://mathematica.stackexchange.com/questions/100957/how-to-count-number-of-small-dots-in-a-picture
I have this picture of small particles in a polymer film. I want to count how many particles in the figure, so that I can have a rough estimation of the particle density. But the image quality is ...
- asked by MYG (8 votes), answered by Graumagier (4 votes)
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[Why some GeoProjections show just half of Chukotka region (Russian map)] http://mathematica.stackexchange.com/questions/101334/why-some-geoprojections-show-just-half-of-chukotka-region-russian-map
I’ve moved to V.10.3 as suggested and proceed with Russian map (the aim is to geoplot regional distributions of some values). Notice most eastern Russian region - Chukotka. Chukotka, unlike other ...
- asked by garej (7 votes), answered by Peter Roberge (1 vote)
================================== Greatest hits from previous weeks: ==================================
[How can I improve Mathematica’s resolution on a macbook retina display?] http://mathematica.stackexchange.com/questions/18419/how-can-i-improve-mathematicas-resolution-on-a-macbook-retina-display
Mathematica 9.0 looks a bit fuzzy on the retina screen, how can I increase the resolution?
Here another screenshot showing a direct comparison between the browser and Mathematica
- asked by Tom Wellington (38 votes), answered by programming_historian (20 votes)
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[How do I draw a pair of buttocks?] http://mathematica.stackexchange.com/questions/66538/how-do-i-draw-a-pair-of-buttocks
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
- asked by Simpleton Jack (236 votes), answered by mikuszefski (360 votes)
================================== Can you answer these? ==================================
[Using Mathematica with touchscreens] http://mathematica.stackexchange.com/questions/101089/using-mathematica-with-touchscreens
I really like using my Windows 10 touchscreen to move around in websites, documents, etc. It doesn’t work in Mathematica. Can that be fixed by changing a global notebook setting, or is it something ...
- asked by George Wolfe (4 votes)
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[Theorem Proving]http://mathematica.stackexchange.com/questions/101201/theorem-proving
It’s a hard for me to write english so I’ll try to go straight to my problem. There is abstract predicate f, that takes two parameters. There are also two other predicates b and u:
b[x_, y_] := ...
- asked by rattrapper (5 votes)
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[Initializing FinancialData indices .... never finishes] http://mathematica.stackexchange.com/questions/101339/initializing-financialdata-indices-never-finishes
Retrieving data using FinancialData became more unreliable in the last couple of months, but simply retrying was enough to finally get the data. Now it seems to be nearly completely broken in ...
- asked by Karsten 7. (3 votes)
================================== Top new questions this week: ==================================
[Wiggly and imprecise animated gif output] http://mathematica.stackexchange.com/questions/100628/wiggly-and-imprecise-animated-gif-output
Trying to make animated gif of zooming into famous Ford circles. With the code
visibleQ[lh_, hr_, c_, k_] := Which[ lh >= 1/(2 k), If[2 c k^2 <= 1 && lh^2 < c (1 - c k^2), True, ... - asked by (12 votes), answered by Michael E2 (7 votes)
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[What is the difference between Dynamic[x] and Dynamic[ h[x] ] for DynamicModule variables?] http://mathematica.stackexchange.com/questions/100828/what-is-the-difference-between-dynamicx-and-dynamic-hx-for-dynamicmodule
Why plain Dynamic[x] is less sensitive and less likely to automatically be updated than e.g. Dynamic[x]?
The issue was raised here couple of times but I don’t remember any general answer, just work ...
- asked by Kuba (11 votes)
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[Pick elements from list "separately"] http://mathematica.stackexchange.com/questions/100696/pick-elements-from-list-separately
I have the following list I want to pick elements from:
mylist = 1, 5, 7, 3, 4, 7, 2, 9, 9, 1, 10, 12, 2, 64, 34, 64
I have another list with 0’s and 1’s which is my selector:
selector = 1, 1, ...
- asked by holistic (11 votes), answered by eldo (11 votes)
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[A quicker than outer] http://mathematica.stackexchange.com/questions/100551/a-quicker-than-outer
I need to get a matrix \(\{a(x_i-x_j)\}\), where \(x_i\) form a partition of an interval, \(a(x)\) is a given function. I use
In[67]:= a[x_?NumericQ] := N[Exp[-Abs[x]]]; x = Table[-10 + 0.02 (j - ...
- asked by Dmitri (11 votes), answered by Szabolcs (14 votes)
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[Converting a list of rules to a list of lists] http://mathematica.stackexchange.com/questions/100700/converting-a-list-of-rules-to-a-list-of-lists
What are some easy ways to convert the list of Rules
{"Joe" -> 94, "Jane" -> 85, "Bob" -> 82, "Bill" -> 83, "Michelle" -> 98} into a list of lists: ...
- asked by David (9 votes), answered by eldo (14 votes)
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[Magnifying Glass on a Plot] http://mathematica.stackexchange.com/questions/100691/magnifying-glass-on-a-plot
Although there is a trick in TEX magnifying glass but I want to know is there any function to magnifying glass on a plot with Mathematica?
For example for a function as Sin[x] and at x=Pi/6
Below, ...
- asked by Ackaran (9 votes), answered by Karsten 7. (13 votes)
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[How to extract a region shape from an 2 colour image?] http://mathematica.stackexchange.com/questions/100578/how-to-extract-a-region-shape-from-an-2-colour-image
I’ll start by saying that I don’t know anything about image processing. I have an image and I need to extract its outermost shape for use in a WordCloud. The image only has two colours and the ...
- asked by Edmund (9 votes), answered by nikie (4 votes)
================================== Greatest hits from previous weeks: ==================================
[How to express trigonometric equation in terms of of given trigonometric function?] http://mathematica.stackexchange.com/questions/434/how-to-express-trigonometric-equation-in-terms-of-of-given-trigonometric-functio
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
Sin[x]^2+Cos[x]^2==1 Sin[x]/Cos[x]==Tan[x] ...
- asked by Prashant Bhate (24 votes), answered by Simon (28 votes)
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[How to find all the local minima/maxima in a range] http://mathematica.stackexchange.com/questions/5575/how-to-find-all-the-local-minima-maxima-in-a-range
I want to find :
all local maxima in range all local minima in range
From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ...
- asked by Margus (52 votes), answered by Daniel Lichtblau (56 votes)
================================== Can you answer these? ==================================
[Solving this system of nonlinear equations] http://mathematica.stackexchange.com/questions/100466/solving-this-system-of-nonlinear-equations
Edit Interestingly, I realized solving my problem with \(2n\) equations appeared to be more efficient than using mathematical results on the solutions to reduce the problem to \(n\) equations (the \(n\) ...
- asked by anderstood (2 votes)
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[Share variables among notebooks with different Kernels] http://mathematica.stackexchange.com/questions/100760/share-variables-among-notebooks-with-different-kernels
So I have a server running in another notebook with a secondary kernel. I run my main notebook and launch the server notebook, but I have configured the variables in my main one, and can’t find a way ...
- asked by jaimehrubiks (2 votes)
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[Planning flights for a special route] http://mathematica.stackexchange.com/questions/100768/planning-flights-for-a-special-route
I want to plan a world trip with Mathematica. So I already have the dataset with all the cities I want to visit and the tour (with the command FindShortestTour). So now I want to know how to come from ...
- asked by Kristina (3 votes)
================================== Top new questions this week: ==================================
[Is Mathematica worth it for me?] http://mathematica.stackexchange.com/questions/100072/is-mathematica-worth-it-for-me
I’m 13 years old and in 7th grade. I’m currently in Algebra 1, and I have fallen in love with both math and programming.
When I came upon Mathematica, it was awesome. My two favorite things fused ...
- asked by TreFox (50 votes), answered by Pillsy (33 votes)
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[GroupBy twice gives different results] http://mathematica.stackexchange.com/questions/100139/groupby-twice-gives-different-results
update: confirmed as a bug related to ’N’ when using GroupBy or GatherBy. It is a bug at least since version 7
It took me quite a lot of time to finally trace down to this strange output. I really ...
- asked by matheorem (25 votes), answered by Patrick Stevens (15 votes)
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[How to make a blob in 3D?] http://mathematica.stackexchange.com/questions/99754/how-to-make-a-blob-in-3d
I am trying to make a blob like the one shown below, but in 3D so I can rotate it. I’m trying to use ParametricPlot3D or SphericalPlot3D. I can make a sphere easily. But my knowledge of how to modify ...
- asked by Michael McCain (20 votes), answered by Eric Towers (12 votes)
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[Coordinate system transformation problem (about Euler angle)] http://mathematica.stackexchange.com/questions/100054/coordinate-system-transformation-problem-about-euler-angle
This question comes from the work that constructing the general cylinder by the NURBS. I have implemented the point-set \(P_1,P_2,\cdots ,P_n\) that in the \(O-xyz\) plane, now I want to implement the ...
- asked by Shutao TANG (14 votes), answered by J. M. (9 votes)
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[List of symbols marked [[EXPERIMENTAL]] in the documentation] http://mathematica.stackexchange.com/questions/100058/list-of-symbols-marked-experimental-in-the-documentation
Some of the built-in Wolfram Language symbols are marked as [[EXPERIMENTAL]] in the documentation. For example
[Echo]
How can I get a list of all the symbols marked as [[EXPERIMENTAL]]?
(This ...
- asked by Karsten 7. (14 votes), answered by Karsten 7. (20 votes)
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[Random letters: What is the chance, that true words are coming?] http://mathematica.stackexchange.com/questions/99800/random-letters-what-is-the-chance-that-true-words-are-coming
Suppose, that we are just typing random letters with our keyboards(we use space bar too). We don’t make difference between big and small letters. If we work for a long time, how much from the words ...
- asked by Arquis (13 votes), answered by belisarius has settled (18 votes)
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[How to take and evaluate a specific part of a list without evaluating the rest?] http://mathematica.stackexchange.com/questions/100217/how-to-take-and-evaluate-a-specific-part-of-a-list-without-evaluating-the-rest
I have a large list, for example, lis = {x + y, x y, Sin[x] y + Exp[y], x^2 y} and its elements depend on variables x and y. Later I assign numerical values to x and y x = {1, 2, 3, 4, 5} y = {3, ...
- asked by renphysics (9 votes), answered by Chris Degnen (9 votes)
================================== Greatest hits from previous weeks: ==================================
[How to use Mathematica functions in Python programs?] http://mathematica.stackexchange.com/questions/4643/how-to-use-mathematica-functions-in-python-programs
I’d like to know how can I call Mathematica functions from Python.
I appreciate a example, for example, using the Mathematica function Prime.
I had search about MathLink but how to use it in Python ...
- asked by GarouDan (35 votes), answered by GarouDan (14 votes)
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[Mathematica sporadically crashes on open] http://mathematica.stackexchange.com/questions/32232/mathematica-sporadically-crashes-on-open
Sometimes, when I open Mathematica, while the opening splash screen still says "Initializing Kernel Connections", Windows will tell me that "Wolfram Mathematica 9 has stopped working". This will ...
- asked by William Kunkel (9 votes), answered by Bingo (5 votes)
================================== Can you answer these? ==================================
[Can’t get Mathematica to Import PDF files with diacritics on the file name] http://mathematica.stackexchange.com/questions/99980/cant-get-mathematica-to-import-pdf-files-with-diacritics-on-the-file-name
Tested with versions 9.0.0, 10.0.2 and 10.3.0, all under OS X 10.10.5. The drag-and-drop front-end functionality also results in $Failed. Surprisingly, Importing, JPEGs, TXTs, and XLSX work just ...
- asked by Aisamu (4 votes)
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[Where can I find documentation on use of special characters in templates?] http://mathematica.stackexchange.com/questions/100023/where-can-i-find-documentation-on-use-of-special-characters-in-templates
I am new to Templates. I have seen the usage "\!\(\*StyleBox ...)" as here: disabling templates What does the string "!(*" accomplish and can I find some documentation of this notation?
- asked by John McGee (1 vote)
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[Exponential Matrix Diffentiation] http://mathematica.stackexchange.com/questions/100214/exponential-matrix-diffentiation
I have been struggling with the following question while solving an optimization problem in \(\mathbb {R}_{+}^G\). Basically, I have \[\min _{y \in \mathbb {R}_{+}^G} F(y) = y^{T}\mathcal {K} + \exp (-y^{T} ... \]
- asked by Guilherme Thompson (1 vote)
================================== Top new questions this week: ==================================
[Terrifying performance decrease for contour/density plots in v10.1 -> 10.3] http://mathematica.stackexchange.com/questions/99255/terrifying-performance-decrease-for-contour-density-plots-in-v10-1-10-3
I setup for download a test dataset at http://www.inrim.it/~magni/cm.dat.gz (a set of 64800 triplets x,y,z).
The behavior can be reproduced with the following code:
link = ...
- asked by alessandro (24 votes), answered by Jason B (13 votes)
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[Cyclic Take function?] http://mathematica.stackexchange.com/questions/99188/cyclic-take-function
Is there some direct and simple "cyclic Take", sometimes also known as "overtake" in Mathematica. That is, if the take specification runs out of elements, it just cycles back to the beginning (as many ...
- asked by murray (21 votes), answered by kglr (22 votes)
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[Speeding up generation of block diagonal matrix] http://mathematica.stackexchange.com/questions/99467/speeding-up-generation-of-block-diagonal-matrix
I’m struggling with the following problem. I have \(48\) square matrices (full, filled with real machine precision numbers, thus are packed, all different) of size \(128\). I wolud like to place them on a ...
- asked by mmal (16 votes), answered by ybeltukov (14 votes)
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[Integrate returns imaginary answer for smooth, real function] http://mathematica.stackexchange.com/questions/99395/integrate-returns-imaginary-answer-for-smooth-real-function
Bug introduced in 7 or earlier and persisting through 10.3
I’m trying to evaluate the integral:
\[\int _0^{\infty } \frac {1}{4 b \sqrt {\pi } r} e^{-(b-r)^2}(e^{4 b r} - 1) \mathrm {d}r\]
with ...
- asked by Kevin Driscoll (15 votes)
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[Detecting an ellipse in a glaucoma photo] http://mathematica.stackexchange.com/questions/99578/detecting-an-ellipse-in-a-glaucoma-photo
For glaucoma diagnosis it is common to determine a "cup to disk ratio" which compares the diameter of the optic disk (VDD) and optic cup (VCD). The optical disk is visible as a circular red feature ...
- asked by indra ginanjar A.T (14 votes), answered by belisarius has settled (17 votes)
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[How to implement the general array broadcasting method from NumPy?] http://mathematica.stackexchange.com/questions/99171/how-to-implement-the-general-array-broadcasting-method-from-numpy
A friend of mine introduced array broadcasting in the Python NumPy package which is very convenient (and also highly efficient).
The idea is perfectly shown in this picture:
Basically, the method ...
- asked by matheorem (14 votes), answered by Pillsy (15 votes)
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[Derivative of a pure function with SlotSequence] http://mathematica.stackexchange.com/questions/99439/derivative-of-a-pure-function-with-slotsequence
I can live with this but I can’t figure out why the following is 0:
Derivative[1][f[##] &][x] 0 From documentation for Derivative: [...] Whenever Derivative[n][f] is generated, the WL ...
- asked by Kuba (14 votes), answered by Michael E2 (13 votes)
================================== Greatest hits from previous weeks: ==================================
[Even Fibonacci numbers] http://mathematica.stackexchange.com/questions/37266/even-fibonacci-numbers
Today, I found the Euler Project. Problem #2 is
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
1, ...
- asked by Shutao TANG (26 votes), answered by rcollyer (34 votes)
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[How can I plot the direction field for a differential equation?] http://mathematica.stackexchange.com/questions/8841/how-can-i-plot-the-direction-field-for-a-differential-equation
I’d like to plot the graph of the direction field for a differential equation, to get a feel for it. I’m a novice, right now, when it comes to plotting in Mathematica, so I’m hoping that someone can ...
- asked by Matt Groff (16 votes), answered by Peter Breitfeld (13 votes)
================================== Can you answer these? ==================================
[Odd Coloring with GeoRegionValuePlot] http://mathematica.stackexchange.com/questions/99478/odd-coloring-with-georegionvalueplot
When I’m plotting data with GeoRegionValuePlot, I’m getting some strange coloring errors:
The grid included shows the top 10 countries with arable land per population. However, Australia is colored ...
- asked by DavisDude (1 vote)
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[Find regions in which the roots of a third degree polynomial are real] http://mathematica.stackexchange.com/questions/99167/find-regions-in-which-the-roots-of-a-third-degree-polynomial-are-real
I have to find the roots of a third degree polynomial in \(\phi \) that depends from 3 parameters, namely \(t,s,w\in \mathbb R\). In order to do that I’ve used the command Solve, in the following way:
...
- asked by Claretta (5 votes)
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[Works with example numbers, but not with variables alone] http://mathematica.stackexchange.com/questions/99575/works-with-example-numbers-but-not-with-variables-alone
The following code prints the correct solution for variable a (2.23). But if i comment out the 5 given example numbers on top it fails. If i remove some of the constraints at the bottom (&& ...
- asked by JoDo (1 vote)
================================== Top new questions this week: ==================================
[How to draw cylinders inside a cube] http://mathematica.stackexchange.com/questions/98724/how-to-draw-cylinders-inside-a-cube
I want to create the following graphic (ignore the unit vectors).
What I do is the following (not the most elegent and smart way I guess:-)!):
1) Use the code below to generate randomly distributed ...
- asked by dimitris (23 votes), answered by ybeltukov (37 votes)
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[Sparse Cholesky Decomposition] http://mathematica.stackexchange.com/questions/98702/sparse-cholesky-decomposition
I am working with square matrices with a special form, which for large rank ($> 100,000$) would be best stored and manipulated as a SparseArray. I believe that the Cholesky decomposition of these ...
- asked by Eric Brown (17 votes), answered by J. M. (16 votes)
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[Histogram3D with various colors and textures on cuboids’ faces] http://mathematica.stackexchange.com/questions/98687/histogram3d-with-various-colors-and-textures-on-cuboids-faces
I’m trying to produce an Histogram3D-like graph, but with a little more customization.
In particular I want to manually specify the color of each cuboid and to print some information on the top ...
- asked by glance (14 votes), answered by Taiki (10 votes)
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[Can anyone explain this weird Plot3D error?] http://mathematica.stackexchange.com/questions/98813/can-anyone-explain-this-weird-plot3d-error
This is more of a fun question because I see the source of the error, but cannot explain what Plot3D is doing. Can you figure it out?
L = 111; X = Table[{0, 0}, {n, 1, L}]; X3D[n_, m_] := ...
- asked by lynvie (13 votes), answered by Michael E2 (6 votes)
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[Piecewise imposes internal boundaries in NDSolve - is this expected?] http://mathematica.stackexchange.com/questions/98734/piecewise-imposes-internal-boundaries-in-ndsolve-is-this-expected
In the following code I used True as the predicate for DirichletCondition and found that the boundary condition was applied not only at the boundary of the specified region but also at the internal ...
- asked by Simon Woods (13 votes), answered by user21 (8 votes)
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[What is the difference between a .wl package and a .m package?] http://mathematica.stackexchange.com/questions/98981/what-is-the-difference-between-a-wl-package-and-a-m-package
In Mathematica 10.x, one now has both .wl Wolfram Language Packages and .m Wolfram Mathematica Packages.
What’s the difference? Is one of the two formats to be preferred in certain situations and, ...
- asked by murray (12 votes)
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[Defer, Hold, Unevaluated, Inactivate – which one when?] http://mathematica.stackexchange.com/questions/98874/defer-hold-unevaluated-inactivate-which-one-when
What are some guidelines on which function to select from among the superficially similar functions Defer, Hold, Unevaluated, and Inactivate?
Consider, for example:
Defer[Defer[Sum[1/k^2, {k, 1, ...
- asked by murray (12 votes)
================================== Greatest hits from previous weeks: ==================================
[Python-style plots in Mathematica] http://mathematica.stackexchange.com/questions/84877/python-style-plots-in-mathematica
I love making plots in Mathematica. And I love to spend a lot of time making high-quality plots that maximize readability and aesthetics. For most cases, Mathematica can make very beautiful images, ...
- asked by Pablo Galindo Salgado (49 votes), answered by halirutan (49 votes)
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[What are the most common pitfalls awaiting new users?] http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by belisarius has settled (278 votes), answered by Michael E2 (148 votes)
================================== Can you answer these? ==================================
[How do I determine which ChartElementDataFunction is Automatic?] http://mathematica.stackexchange.com/questions/98820/how-do-i-determine-which-chartelementdatafunction-is-automatic
In the course of exploring @kglr's answer to Edmund's question gain some insight into how I might answer my own question here, I came across the undocumented System`ChartElementData function, which ...
- asked by Pillsy (7 votes)
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[Control Front End in "mathlink" mode] http://mathematica.stackexchange.com/questions/98686/control-front-end-in-mathlink-mode
Note: This question was already posted in the Wolfram community.
In a terminal math session, we can start a front end (FE) easily by launching it though LinkLaunch or by using functions provided in ...
- asked by halirutan (11 votes)
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[Multivariate Path Construction using Sobol numbers] http://mathematica.stackexchange.com/questions/98914/multivariate-path-construction-using-sobol-numbers
I am sharing my code,which I have tried to perform as per the instruction mentioned below. Please correct it so that I could get my output.
Instruction: Use the first m dimensions of the Sobol vector ...
- asked by Pankaj Mani (1 vote)
================================== Top new questions this week: ==================================
[Incorrect Timing of Total] http://mathematica.stackexchange.com/questions/98453/incorrect-timing-of-total
For demonstrating how fast C-compiled functions can be, in one of my courses I use the following function for finding the sum of a list of reals:
myTotal = Compile[{{lst, _Real, 1}},Module[{s=0.}, ...
- asked by Fred Simons (17 votes), answered by ilian (12 votes)
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[Aggregation queries on lists of associations in 10.3] http://mathematica.stackexchange.com/questions/98277/aggregation-queries-on-lists-of-associations-in-10-3
Bug introduced in 10.3
Some aggregation queries applied to a list of associations (or Dataset’s with this structure) lock up the front end or crash the kernel in Version 10.3.
xx = {<|"a" -> ...
- asked by Daniel W (14 votes), answered by SquareOne (7 votes)
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[On making a graphical real-time memory usage monitor] http://mathematica.stackexchange.com/questions/98205/on-making-a-graphical-real-time-memory-usage-monitor
I’d like to make a graphical version of
Dynamic[Refresh[MemoryInUse[], UpdateInterval -> 1]] A naive implementation would be something like: miu = {}; Dynamic[Refresh[ListPlot[AppendTo[miu, ...
- asked by kjo (12 votes), answered by Karsten 7. (7 votes)
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[How to sort list of mixed types of elements with each type a specified canonical order?] http://mathematica.stackexchange.com/questions/98438/how-to-sort-list-of-mixed-types-of-elements-with-each-type-a-specified-canonical
For example, here is a list
{{1, "u"}, {6, "d"}, {3, "u"}, {4, "d"}, {2, "u"}, {5, "u"}, {3, "d"}, {1, "d"}, {4, "u"}, {2, "d"}, {5, "d"}, {6, "u"}} The default canonical order for integer is ...
- asked by matheorem (11 votes), answered by belisarius is forth (14 votes)
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[How do you concatenate matrices? And how do you make block matrices?] http://mathematica.stackexchange.com/questions/98406/how-do-you-concatenate-matrices-and-how-do-you-make-block-matrices
This is pretty trivial to do in Matlab, but I have not seen a function for it in Mathematica. Here is how you can do it with Join and Transpose. Is there an easier way to do it than this?
...
- asked by luke wendt (10 votes), answered by Taiki (12 votes)
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[Association Subtotals with Lists as Keys] http://mathematica.stackexchange.com/questions/98346/association-subtotals-with-lists-as-keys
I have the following Association:
as = <|{5, 2, 1} -> 3, {6, 1, 4} -> 9, {5, 1, 9} -> 12, {5, 2, 4} -> 6, {6, 2, 8} -> 10|>;
I want to total the values on the right side of the ...
- asked by eldo (10 votes), answered by Pillsy (13 votes)
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[get position index for all element in a list] http://mathematica.stackexchange.com/questions/98170/get-position-index-for-all-element-in-a-list
For example
mat={{a,b},{c,a,a}} How to write a function posindex that posindex[mat] will give {{a -> {1, 1}, b -> {1, 2}}, {c -> {2, 1}, a -> {2, 2}, a -> {2, 3}} And the function ...
- asked by matheorem (10 votes), answered by Michael E2 (8 votes)
================================== Greatest hits from previous weeks: ==================================
[3D surface that looks like a virus] http://mathematica.stackexchange.com/questions/74193/3d-surface-that-looks-like-a-virus
I have been recently using Mathematica for composing animations that are part of the supplementary information of my papers.
I am currently trying to build an animation that involves a viral ...
- asked by user2098 (16 votes), answered by Chris Degnen (18 votes)
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[Mathematica Minecraft] http://mathematica.stackexchange.com/questions/19669/mathematica-minecraft
Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
- asked by faleichik (131 votes), answered by faleichik (176 votes)
================================== Can you answer these? ==================================
[Triggering events based on choices made inside of system dialogs (e.g. window close)] http://mathematica.stackexchange.com/questions/98091/triggering-events-based-on-choices-made-inside-of-system-dialogs-e-g-window-cl
I’m trying to arrange for Mathematica to perform a certain action every time a notebook is saved or closed (with or without saving). The obvious way to do this would be through event handling. So, ...
- asked by Paco Jain (5 votes)
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[ListContourPlot and ListContourPlot3D use better interpolation for arrays of values than for lists of tuples (i.e. x,y,z,f[x,y,z]..] http://mathematica.stackexchange.com/questions/98145/listcontourplot-and-listcontourplot3d-use-better-interpolation-for-arrays-of-val
From reading the documentation, it seems that ListContourPlot3D should work equally well on an array versus a list of tuples,
?ListContourPlot3D ListContourPlot3D[array] generates a contour plot ...
- asked by Jason B (10 votes)
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[Size problems combining objects in a Graphics using Inset] http://mathematica.stackexchange.com/questions/98282/size-problems-combining-objects-in-a-graphics-using-inset
The Problem
I need to put together different graphics objects in a precise way inside a Graphics. Some objects are drawn directly by graphics primitives, some others are the result of calls to ...
- asked by Guido (4 votes)
================================== Top new questions this week: ==================================
[Recursively appending elements to a list] http://mathematica.stackexchange.com/questions/97684/recursively-appending-elements-to-a-list
In wanting to demonstrate the power of Mathematica, I wanted to show my 11-year-old son how we could validate that his sequences homework was correct. We could generate the next value in sequence in a ...
- asked by AnthonyMiller (15 votes), answered by J. M. (19 votes)
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[What is "MemoryMonitor"?] http://mathematica.stackexchange.com/questions/97810/what-is-memorymonitor
Evaluating one of the following inputs
CurrentValue[EvaluationNotebook[], WindowElements] CurrentValue[$FrontEndSession, WindowElements] CurrentValue[$FrontEnd, WindowElements]
...
- asked by Karsten 7. (12 votes), answered by m_goldberg (10 votes)
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[Pop-up documentation for "The new function of the day"] http://mathematica.stackexchange.com/questions/97552/pop-up-documentation-for-the-new-function-of-the-day
The Wolfram Language has more than 5000 built-in functions and constants.
functionslist = Flatten[ Names[#] & /@ Flatten[ {# <> "*", "$" <> # <> "*"} & /@ ...
- asked by rhermans (12 votes), answered by J. M. (5 votes)
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[ListContourPlot has wrong colouring: workaround?] http://mathematica.stackexchange.com/questions/97596/listcontourplot-has-wrong-colouring-workaround
ListContourPlot uses the wrong colouring here:
res = Import["https://dl.dropboxusercontent.com/u/38623/res.wdx", "WDX"]; ListContourPlot[res, Contours -> Range[0.66, 0.9, 0.02], ColorFunction ...
- asked by Szabolcs (12 votes), answered by Jason B (9 votes)
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[How do you handle upgrade frequency now that minor releases come so quickly?] http://mathematica.stackexchange.com/questions/97493/how-do-you-handle-upgrade-frequency-now-that-minor-releases-come-so-quickly
Does anyone understand the Mathematica upgrade treadmill these days? With the minor releases (10.2, 10.3) coming out fairly quickly and the upgrade price associated with each, I have no idea what my ...
- asked by sblom (12 votes)
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[More efficient method to compute moments of the Johnson \(S_B\) distribution] http://mathematica.stackexchange.com/questions/97750/more-efficient-method-to-compute-moments-of-the-johnson-s-b-distribution
Here is a very specific feature request. I need
Mean[JohnsonDistribution["SB", \[Gamma], \[Delta], 0, 1]] When I issue e.g. Table[N[Mean[JohnsonDistribution["SB", \[Gamma], \[Delta], 0, 1]]], {\[Gamma], -10, 10}, {\[Delta], 1, 10}] - asked by (11 votes), answered by J. M. (15 votes)
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[Path Names Longer Then 256 on Windows] http://mathematica.stackexchange.com/questions/97736/path-names-longer-then-256-on-windows
Is there a way to work with pathnames that are longer then the typical 256 in Mathematica?
For example run the following in Cygwin
echo 1 > ...
- asked by William (11 votes), answered by WReach (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Mathematica Minecraft] http://mathematica.stackexchange.com/questions/19669/mathematica-minecraft
Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
- asked by faleichik (131 votes), answered by faleichik (176 votes)
—————————-
[3D surface that looks like a virus] http://mathematica.stackexchange.com/questions/74193/3d-surface-that-looks-like-a-virus
I have been recently using Mathematica for composing animations that are part of the supplementary information of my papers.
I am currently trying to build an animation that involves a viral ...
- asked by user2098 (16 votes), answered by Chris Degnen (18 votes)
================================== Can you answer these? ==================================
[How to model discontinuities in a NonlinearStateSpaceModel] http://mathematica.stackexchange.com/questions/97717/how-to-model-discontinuities-in-a-nonlinearstatespacemodel
I know that it is possible to model discontinuities like bouncing and other collisions by using WhenEvent with NDSolve.
However, I am using the tools for Non linear systems and I’d like to know if ...
- asked by RationalAsh (2 votes)
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[How to pass a custom method to a particular option?] http://mathematica.stackexchange.com/questions/97753/how-to-pass-a-custom-method-to-a-particular-option
In an answer to my question More efficient method to compute moments of the Johnson \(S_B\) distribution, J. M. has come up with a method to compute the moments of the Johnson \(S_B\) distribution, which ...
- asked by (4 votes)
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[Scaling 1D ArrayPlot divide by zero error] http://mathematica.stackexchange.com/questions/97467/scaling-1d-arrayplot-divide-by-zero-error
I am trying to overlay an ArrayPlot onto a WaveletScalogram, using the helpful answer here; however, my ArrayPlot is one-dimensional.
My code:
Show[{ WaveletScalogram[trainWaveData["A1 HbO"], ...
- asked by Lylax (2 votes)
================================== Top new questions this week: ==================================
[DumpSave 10.2 style from 10.3] http://mathematica.stackexchange.com/questions/97357/dumpsave-10-2-style-from-10-3
Szabolcs has asked WRI support about mx files, in particular:
Can we expect that MX files written by Mathematica 10.0.0 will be readable by future point released such as 10.0.1 or 10.0.2?
...
- asked by Kuba (14 votes)
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[Plot3D is incorrectly returning "1/0. encountered"] http://mathematica.stackexchange.com/questions/97104/plot3d-is-incorrectly-returning-1-0-encountered
The line of code
Plot3D[1/y, {x, 0, 1}, {y, x + 1, x + 2}]
is returning several "Power::infy: Infinite expression 1/0. encountered." error messages, and then returning an empty plot. But the ...
- asked by tparker (13 votes), answered by rhermans (8 votes)
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[Fast Selections Testing on Inequality] http://mathematica.stackexchange.com/questions/97083/fast-selections-testing-on-inequality
Is there a functional idiom for fast selections testing on inequality?
For example, finding values from list a & b where the key is less than or equal to a value, in this case 4 or 9.
An ...
- asked by Chris Degnen (13 votes), answered by Chris Degnen (5 votes)
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[Generate two random numbers with constraint] http://mathematica.stackexchange.com/questions/97424/generate-two-random-numbers-with-constraint
I want to generate two random numbers p and q between 0.5 and 1. They are connected by the following constraint \(1/2q\> ;p\). How to do that?
- asked by Chandan Datta (12 votes), answered by rhermans (18 votes)
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[How to evaluate the second argument of Cases only once] http://mathematica.stackexchange.com/questions/96939/how-to-evaluate-the-second-argument-of-cases-only-once
I’d like to find a fast but readable way to achieve the following:
Cases[RandomInteger[{AbsoluteTime["2001"], AbsoluteTime["2003"]}, 1000], a_ /; a > AbsoluteTime["2002"]]
The correct result ...
- asked by Italianice (10 votes), answered by Michael E2 (11 votes)
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[How to predict the degree of the first series coefficient?] http://mathematica.stackexchange.com/questions/97313/how-to-predict-the-degree-of-the-first-series-coefficient
Given an expression f that is a function of x and a number x0, what is the least integer n that produces a non-zero coefficient in Series[f, x, x0, n]?
[1] For instance, here, is the answer is n = ...
- asked by Michael E2 (9 votes), answered by bbgodfrey (0 votes)
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[Trying to find the asymptote to a function] http://mathematica.stackexchange.com/questions/97365/trying-to-find-the-asymptote-to-a-function
I am trying to find the asymptote to a solution of a differential equation.
I solved $x'(t) = \sin(x(t) + t)$ using NDSolve and plotted my solution. sol = NDSolve[{x'[t] == Sin[x[t] + t], x[0] == ...
- asked by Jacobadtr (9 votes), answered by bbgodfrey (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Generating visually pleasing circle packs] http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs
EDIT: (my conclusion and thank you note) I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you had fun and enjoyed it the same as I did.
I would like to ...
- asked by VividD (86 votes), answered by level1807 (51 votes)
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[Is there a syntax for single-line comments for notebooks?] http://mathematica.stackexchange.com/questions/1496/is-there-a-syntax-for-single-line-comments-for-notebooks
I’m aware that I can use (* ... *) to comment out stuff in a notebook. Many languages have a syntax for single-line comments, such as
// in C, C++, Java, C#, ... # in shell, Python, ... For ...
- asked by Peeter Joot (35 votes), answered by Szabolcs (42 votes)
================================== Can you answer these? ==================================
[SyntaxInformation: take allowed options from multiple symbols possible?] http://mathematica.stackexchange.com/questions/97411/syntaxinformation-take-allowed-options-from-multiple-symbols-possible
Suppose I have a function like
Options[f] = {foo -> 1}; f[opt : OptionsPattern[{f,g}]] := h@g[Sequence @@ FilterRules[{opt}, Options[g]]]
I purposefully do not want to append Options[g] to ...
- asked by Szabolcs (4 votes)
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[Is there any way to export vector graphics with shading?] http://mathematica.stackexchange.com/questions/97305/is-there-any-way-to-export-vector-graphics-with-shading
This has irked me for a while as I really feel its a significant shortfall in Mathematica’s abilities but maybe I am missing something.
I would like to export simple graphics with shading in a ...
- asked by Quantum_Oli (9 votes)
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[Why is 13 the smaller height dimension of a Graphics?] http://mathematica.stackexchange.com/questions/97364/why-is-13-the-smaller-height-dimension-of-a-graphics
It seems that you cannot get a Graphics image with a height dimension less than 13. Trying to draw something and then asking for the ImageDimensions of the resulting Graphics, you will get three ...
- asked by Guido (6 votes)
================================== Top new questions this week: ==================================
[Progress bar for FullSimplify] http://mathematica.stackexchange.com/questions/96602/progress-bar-for-fullsimplify
Sometimes FullSimplify takes a really long time and it is not really clear if it makes sense to wait another half an hour in hopes for it to finish, or if it will actually take three years in which ...
- asked by Kagaratsch (18 votes), answered by Sjoerd C. de Vries (26 votes)
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[Construct a master curve from data] http://mathematica.stackexchange.com/questions/96393/construct-a-master-curve-from-data
I will try to be as informative as possible.
Clear["Global`*"] I have the following data data91 = {{-0.209091`, 2.89296`}, {0.281818`, 2.92958`}, {0.8`, 2.97535`}, {1.28182`, 3.03028`}, ...
- asked by dimitris (11 votes), answered by Sjoerd C. de Vries (17 votes)
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[Upper bound "Vicious nearest neighbour" algorithm suggestions] http://mathematica.stackexchange.com/questions/96691/upper-bound-vicious-nearest-neighbour-algorithm-suggestions
I am asking a question based on this question from the sister site MSE.
In an effort to make this a self-contained question, I include the fiorst documented posing of the problem by Robert Abilock in ...
- asked by martin (10 votes), answered by Arnoud Buzing (2 votes)
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[Symbolic sum of Stirling numbers gives wrong answer] http://mathematica.stackexchange.com/questions/96575/symbolic-sum-of-stirling-numbers-gives-wrong-answer
This issue originated from my attempt to answer a question on MathOverflow:
Sum[StirlingS2[i, 2], {i, 0, n}]
on Mathematica 10.2.0.0 gives as answer \(\frac {1}{2} (-3 + 2^{1 + n} - 2 n)\), while the ...
- asked by Carlo Beenakker (10 votes), answered by Bob Hanlon (6 votes)
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[Map a function of several arguments] http://mathematica.stackexchange.com/questions/96803/map-a-function-of-several-arguments
I have three lists, e.g.
list1 = {{a,b,...}}; list2 = {{1,2},{3,4},...}; list3 = {{x,y},{z,w},...}; and a function f[x_,y_]:=(* whatever it does *);
I need to get
...
- asked by T. Rihacek (10 votes), answered by Kuba (12 votes)
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[Why does Nearest not support Sqrt?] http://mathematica.stackexchange.com/questions/96588/why-does-nearest-not-support-sqrt
Simple examples with two points
nf1=Nearest[{{0, 0}, {Sqrt[2], Sqrt[2]}}] nf1[{0, 0}, {All, 2.1}] gives {{0, 0}}
This is incorrect. If we test bigger radius, we can find that Mathematica takes ...
- asked by matheorem (9 votes)
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[Unique Element in List] http://mathematica.stackexchange.com/questions/96747/unique-element-in-list
I have a list a, and want to find out whether there is a unique element in the list.
For instance a=x,y,z,y,x has an unique element (z), while a=1,2,3,4,5,1,2,3,4,5 has no unique element.
There ...
- asked by NicoDean (8 votes), answered by J. M. is back. (11 votes)
================================== Greatest hits from previous weeks: ==================================
[1 Plot, 2 Scale/Axis] http://mathematica.stackexchange.com/questions/627/1-plot-2-scale-axis
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
- asked by 500 (87 votes), answered by ArgentoSapiens (83 votes)
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[Mathematica Minecraft] http://mathematica.stackexchange.com/questions/19669/mathematica-minecraft
Some time ago I asked myself: with all these great graphics and interactive capabilities of Mathematica, what kinds of 3D games can be implemented in it? And the answer which came to mind is ...
- asked by faleichik (131 votes), answered by faleichik (175 votes)
================================== Can you answer these? ==================================
[Examples of using Mathematica to solve matrix equations symbolically] http://mathematica.stackexchange.com/questions/96405/examples-of-using-mathematica-to-solve-matrix-equations-symbolically
Suppose we want to solve a linear system like
\[ \left \lbrack \begin {array}{cc}M& S\\ -S^{T}&0 \end {array} \right \rbrack \left \lbrack \begin {array}{c} x\\ y\end {array}\right \rbrack = \left \lbrack \begin {array}{c} f \\g \end {array} \right \rbrack \]
- asked by fred (5 votes)
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[General suggestions to accelerate Simplify and FullSimplify] http://mathematica.stackexchange.com/questions/96476/general-suggestions-to-accelerate-simplify-and-fullsimplify
To my understanding, the function Simplify[] and FullSimplify[] work by applying a series of built-in transformation rules to the expression and trying to minimize the TransformationFunctions in the ...
- asked by Yuchen Xie (1 vote)
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[External and internal Assumptions on ‘PiecewiseExpand‘ and ‘Mod‘] http://mathematica.stackexchange.com/questions/96596/external-and-internal-assumptions-on-piecewiseexpand-and-mod
After this question I’m intrigued about the different behaviors depending where and how the assumptions are given.
PiecewiseExpand[Mod[n, m]] (* case #1 *) (* Mod[n, m] *) PiecewiseExpand[Mod[n, ...
- asked by rhermans (5 votes)
================================== Top new questions this week: ==================================
[How to simplify writing LibraryLink code?]( http://mathematica.stackexchange.com/questions/96127/how-to-simplify-writing-librarylink-code)
LibraryLink is an API for extending Mathematica through C or C++. It is very fast because it gives direct access to Mathematica’s packed array data structure, without even needing to make a copy of ...
- asked by Szabolcs (22 votes), answered by Szabolcs (20 votes)
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[Find the volume of Phobos and Deimos]( http://mathematica.stackexchange.com/questions/96125/find-the-volume-of-phobos-and-deimos)
How can we calculate the volume of a 3D object using the new-in-10 computational geometry functions?
For simple objects this works:
shuttle = ExampleData[{"Geometry3D", "SpaceShuttle"}]
- asked by Szabolcs (17 votes), answered by I_Mariusz (7 votes)
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[Convert binary voxel image to geometric region] (http://mathematica.stackexchange.com/questions/96134/convert-binary-voxel-image-to-geometric-region)
I have a binary voxel image which described a contiguous region in space.
Example:
arr = Array[ Function[{x, y, z}, (1 + Sin[5 x] Sin[5 y] Sin[5 z]/2) - (x^2 + y^2 + z^2)], {100, 100, 100}, ...
- asked by Szabolcs (14 votes), answered by Simon Woods (5 votes)
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[Is it possible to reference "self" from a pure function?]( http://mathematica.stackexchange.com/questions/96220/is-it-possible-to-reference-self-from-a-pure-function)
This would calculate the factorial of 6, if the "self" was the function itself. Is there something that could allow this?
If[#[[1]] > 0, self[{#[[1]] - 1, #[[2]] #[[1]]}], Print[#[[2]]]] &[{6, ...
- asked by MathematicaUser39386 (13 votes), answered by Leonid Shifrin (19 votes)
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[Circle with negative radius?]( http://mathematica.stackexchange.com/questions/96102/circle-with-negative-radius)
Why does this work:
Graphics[{Circle[{0, 0}, -Pi/4]}]
But this doesn’t?
Graphics[{Circle[{0, 0}, N[-Pi/4]]}]
Telling me:
Radius -0.78539816339744828 should be a positive number or pair of ...
- asked by David (12 votes)
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[DSolve documention on web differs greatly from distributed MMA 10.2.0 version] (http://mathematica.stackexchange.com/questions/96089/dsolve-documention-on-web-differs-greatly-from-distributed-mma-10-2-0-version)
In the course of improving my answer to 95361, I noticed that the DSolve documentation on the web is much better written than that distributed with Mathematica 10.2.0 for Microsoft Windows (64-bit) ...
- asked by bbgodfrey (10 votes), answered by Karsten 7. (5 votes)
—————————-
[MapAt with Replace(All) causing kernel crash]( http://mathematica.stackexchange.com/questions/96193/mapat-with-replaceall-causing-kernel-crash)
Bug introduced in 10.1 and fixed in 10.2
I wanted to roll a function that works like /. but only acts on the very first match it encounters.
ReplaceAtFirst = Function[{expr, rule}, ...
- asked by LLlAMnYP (9 votes), answered by LLlAMnYP (4 votes)
================================== Greatest hits from previous weeks: ==================================
[3D surface that looks like a virus] (http://mathematica.stackexchange.com/questions/74193/3d-surface-that-looks-like-a-virus)
I have been recently using Mathematica for composing animations that are part of the supplementary information of my papers.
I am currently trying to build an animation that involves a viral ...
- asked by user2098 (16 votes), answered by Chris Degnen (18 votes)
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[Trying to Visualize a Collatz - The Collatz conjecture]( http://mathematica.stackexchange.com/questions/85718/trying-to-visualize-a-collatz-the-collatz-conjecture)
So I’m new in this and learning— and I happen to have this collatz
collatz[x_, y_] := If[x == 3*y || x == 2*y + 1 || y == 3*x || y == 2*x + 2, 2, 0]
So i want a visual 3D adjacency graph of my ...
- asked by Mia (23 votes), answered by Sjoerd C. de Vries (27 votes)
================================== Can you answer these? ==================================
[How to "fake" a front-end object when running a Mathematica script?] (http://mathematica.stackexchange.com/questions/95779/how-to-fake-a-front-end-object-when-running-a-mathematica-script)
I’m running a Mathematica script (content of which cannot be disclosed here) and some part of it requires "front-end"? Since it’s running in a script, there is not one and it gave the following error: ...
- asked by qazwsx (3 votes)
—————————-
[INTERNAL SELF-TEST ERROR: FileNotify|c|305]( http://mathematica.stackexchange.com/questions/96273/internal-self-test-error-filenotifyc305)
Does anybody know what this error means? Clicking the link in the warning message gives a "page not found", and Googling does not produce anything for this exact error code. I get it whenever I try to ...
- asked by Marius Ladegard Meyer (3 votes)
—————————-
[Does Compilation option "InlineExternalDefinitions"/"InlineCompiledFunctions" lead to unnecessarily complicated nesting?] (http://mathematica.stackexchange.com/questions/96147/does-compilation-option-inlineexternaldefinitions-inlinecompiledfunctions-le)
Question: When an external (possibly complicated) definition f is used inside a compiled function with CompilationOption->{"InlineCompiledFunctions"->True}, does Mathematica really store the ...
- asked by QuantumDot (4 votes)
================================== Top new questions this week: ==================================
[Fast calculation of discrete logarithms] http://mathematica.stackexchange.com/questions/95590/fast-calculation-of-discrete-logarithms
Does Mathematica have any built-in fast algorithms for calculating discrete logarithms over \((\mathbb {Z}_p)^\times \) (the group of integers modulo \(p\))?
Essentially, for a fixed large prime p, a ...
- asked by 2012rcampion (15 votes)
—————————-
[What pseudo-random number generators are available to Mathematica users?] http://mathematica.stackexchange.com/questions/95533/what-pseudo-random-number-generators-are-available-to-mathematica-users
One would think I should be able answer the question I pose in the title for myself by reading the Documentation Center article ref/SeedRandom, but it’s not so simple.
That article does give a list ...
- asked by m_goldberg (13 votes), answered by ilian (15 votes)
—————————-
[Efficient conversion between two partition representations] http://mathematica.stackexchange.com/questions/95410/efficient-conversion-between-two-partition-representations
I have a list of distinct expressions. We can represent a partitioning of list in two ways:
As a list of sublists partitions = a, b, ..., x, y, ..., ....
As a vector of integer partition ...
- asked by Szabolcs (12 votes), answered by Leonid Shifrin (12 votes)
—————————-
[Why do singularities disappear when performing convolutions with the Dirac Delta function?] (http://mathematica.stackexchange.com/questions/95588/why-do-singularities-disappear-when-performing-convolutions-with-the-dirac-delta)
I am attempting to perform a convolution involving the Dirac Delta function:
\(\int _{-\infty }^{\infty } \frac {1}{t+1} \cdot \delta (t+1)\ dt\)
I would expect that the result of this integral is ...
- asked by Peter Crowley (11 votes), answered by I_Mariusz (1 vote)
—————————-
[Determine height of box packed with spheres] (http://mathematica.stackexchange.com/questions/95566/determine-height-of-box-packed-with-spheres)
I got such a wonderful answer regarding The Diagonals of a Regular Octagon, so I thought I’d try asking another question we had on our Pizza and Problem quiz activity at College of the Redwoods. The ...
- asked by David (10 votes), answered by KennyColnago (10 votes)
—————————-
[How to automatically remove text from images?] (http://mathematica.stackexchange.com/questions/95512/how-to-automatically-remove-text-from-images)
I’d like to remove the text in the center of images automatically. To use Inpaint[], you need a mask, but I don’t have one. So really the problem is:
How to build a mask for an image that contains a ...
- asked by M.R. (10 votes), answered by blochwave (36 votes)
—————————-
[Front ends gone wild with named slots] (http://mathematica.stackexchange.com/questions/95351/front-ends-gone-wild-with-named-slots)
Bug introduced in version 10
Assume the following simple expression
{#"Test"}&
Now go in front of the # and just start typing another named slot expression. On my system, the front end ...
- asked by halirutan (10 votes)
================================== Greatest hits from previous weeks: ==================================
[Python-style plots in Mathematica] http://mathematica.stackexchange.com/questions/84877/python-style-plots-in-mathematica
I love making plots in Mathematica. And I love to spend a lot of time making high-quality plots that maximize readability and aesthetics. For most cases, Mathematica can make very beautiful images, ...
- asked by Pablo Galindo Salgado (48 votes), answered by halirutan (49 votes)
—————————-
[How to find all the local minima/maxima in a range] http://mathematica.stackexchange.com/questions/5575/how-to-find-all-the-local-minima-maxima-in-a-range
I want to find :
all local maxima in range
all local minima in range
From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ...
- asked by Margus (51 votes), answered by Daniel Lichtblau (55 votes)
================================== Can you answer these? ==================================
[Time complexity to choose the right overload from the memoized function] http://mathematica.stackexchange.com/questions/95399/time-complexity-to-choose-the-right-overload-from-the-memoized-function
If we want to save some outputs of the function, we often use the memoization pattern as follows,
f[x_]:=f[x]=x f/@Range[10^5]
If I call this function many times for different arguments, ...
- asked by Sungmin (7 votes)
—————————-
[Diagonalisation of equations for NDSolve] http://mathematica.stackexchange.com/questions/95383/diagonalisation-of-equations-for-ndsolve
I have a linear matrix differential equation and I wish to speed up evaluation by diagonalising using eigenvectors. There is an example in Help for finite elements under "swinging beam" that is ...
- asked by Hugh (2 votes)
—————————-
[TableDirections example produces an error message] http://mathematica.stackexchange.com/questions/95321/tabledirections-example-produces-an-error-message
Bug introduced in 10.0 and persisting through in 10.2
Can anyone replicate this? In Mathematica 10.2 on Win 64:
TableForm[{{a, b}, {c, d}, {e, f}}, TableDirections -> Row]
I get the ...
- asked by Alan (9 votes)
================================== Top new questions this week: ==================================
[How to speed up PDF export in Mathematica 10] (http://mathematica.stackexchange.com/questions/94776/how-to-speed-up-pdf-export-in-mathematica-10)
Based on this question: - Version 7 print environment - I set up two 10 page test documents in version 7.0.1 and version 10.1. The version 7 document exported to PDF in 4.18 seconds whereas the ...
- asked by Chris Degnen (19 votes)
—————————-
[How can I import a huge CSV file quickly?] (http://mathematica.stackexchange.com/questions/94752/how-can-i-import-a-huge-csv-file-quickly)
I have two CSV files, each one is around 1 GB of data. When I use Import["file.csv"], it takes a very, very, long time to import the data. So how can I accelerate the import procedure?
The file ...
- asked by m00nlight (17 votes), answered by tesseract (12 votes)
—————————-
[Is it possible to change the order that symbol definitions are checked? (DownValues vs UpValues)] (http://mathematica.stackexchange.com/questions/95087/is-it-possible-to-change-the-order-that-symbol-definitions-are-checked-downval)
Suppose I have the function f with the following definition assigned to it:
f // ClearAll; f // Attributes = { HoldAll }; f /: HoldPattern[ f[x_] + f[y_] ] := upvalue; If I evaluate f[x] + f[y], I ...
- asked by rhennigan (15 votes), answered by halirutan (9 votes)
—————————-
[Is it a bug in Limit?](http://mathematica.stackexchange.com/questions/95052/is-it-a-bug-in-limit)
Bug introduced in 9.0 and fixed in 10.0.0
Mathematica 9 on Windows and WolframAlpha says
Limit[Sin[Sqrt[x+1]]-Sin[Sqrt[x]],x->Infinity] is Interval[{-2,2}].
But actually the limit is 0.
...
- asked by user15961 (13 votes)
—————————-
[Add a vector to a list of vectors]( http://mathematica.stackexchange.com/questions/95033/add-a-vector-to-a-list-of-vectors)
What is the syntax to add v1 to each vector in v2? I know it has to be simple, but I really have searched and not found it.
v1 = {a, b, c} v2 = {{d, e, f}, {g, h, i}, {j, k, l}}
i.e., sum them in ...
- asked by DrBubbles (12 votes), answered by Artes (16 votes)
—————————-
[How to remove a LocalSymbol (or CloudSymbol)?] (http://mathematica.stackexchange.com/questions/94978/how-to-remove-a-localsymbol-or-cloudsymbol)
In version 10.2 LocalSymbol can be used to create a persistent store of a variable. Once this is created I don’t see a method to remove it. How are are they removed.
LocalSymbol["MySolution"] = 7
...
- asked by Edmund (11 votes), answered by ilian (11 votes)
—————————-
[How can I route edges manually for a Graph?] (http://mathematica.stackexchange.com/questions/95013/how-can-i-route-edges-manually-for-a-graph)
Most graph layouts supported by Mathematica use straight lines for edges; or at least something that only depends on the coordinates of the two adjacent vertices of the edge and nothing else.
A ...
- asked by Szabolcs (10 votes), answered by Silvia (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Elegant operations on matrix rows and columns] (http://mathematica.stackexchange.com/questions/3069/elegant-operations-on-matrix-rows-and-columns)
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
- asked by sjdh (91 votes), answered by Mr.Wizard (31 votes)
—————————-
[How to make use of Associations?]( http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations)
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (89 votes), answered by Leonid Shifrin (100 votes)
================================== Can you answer these? ==================================
[Why is an imported plot different from the saved one?] (http://mathematica.stackexchange.com/questions/94757/why-is-an-imported-plot-different-from-the-saved-one)
I have a question concerning the importing of previously saved graphics. So I drew a plot in Mathematica and saved it by right clicking on it and saving it ("save as..."). When I open this (.pdf) ...
- asked by drabus (2 votes)
—————————-
[Number of 4-colorings of Johnson solids] (http://mathematica.stackexchange.com/questions/95066/number-of-4-colorings-of-johnson-solids)
I want to know the number of 4-colorings for all Johnson solids. This is equivalent to evaluating the flow polynomial for the corresponding polyhedral graphs at \(k=4\).
I tried the following to get ...
- asked by Athanasios Evangelou (4 votes)
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[How to have Mathematica pronounce/speak International Phonetic Alphabet?] (http://mathematica.stackexchange.com/questions/95068/how-to-have-mathematica-pronounce-speak-international-phonetic-alphabet)
We know that Speak could read out English words and sentences such as
Speak["this is a sentence"] Unfortunately, Speak only works for English. Speak[" "] will only yield silence.
In fact ...
- asked by Harry (3 votes)
================================== Top new questions this week: ==================================
[Spacing out random walks so they don’t overlap] (http://mathematica.stackexchange.com/questions/94363/spacing-out-random-walks-so-they-dont-overlap)
From an external simulation program, I have lots of particle tracks which follow random walks, all of which start at or near the origin \((0,0)\). This means that when I plot the walks in Mathematica, ...
- asked by blochwave (20 votes), answered by kirma (8 votes)
—————————-
[How to avoid the wiggly text on Ticks and Labels when rotating 3D objects] (http://mathematica.stackexchange.com/questions/94470/how-to-avoid-the-wiggly-text-on-ticks-and-labels-when-rotating-3d-objects)
Motivation
I’m trying to do a nice animation of the rotation of a ParametricPlot3D . My problem is that the Ticks numbers and AxesLabel text wiggle with an undesirable noisy component as the ...
- asked by rhermans (16 votes), answered by P. Fonseca (8 votes)
—————————-
[Efficiently generating 2-D Gaussian random fields on the sphere] (http://mathematica.stackexchange.com/questions/94390/efficiently-generating-2-d-gaussian-random-fields-on-the-sphere)
Context
A couple of years ago I posted this question for an efficient code to generate an n-D Gaussian random field (sometimes called processes in other fields of research), which has applications in ...
- asked by chris (15 votes)
—————————-
[Pattern does not match with Orderless head] (http://mathematica.stackexchange.com/questions/94432/pattern-does-not-match-with-orderless-head)
Why does the following pattern matching not succeed?
ClearAll[f]; SetAttributes[f,Orderless]; HoldForm[f[a,d[],b,c]]/.HoldPattern[f[a,d[],b,z_]]:>{z} (* f[a,d[],b,c] *)
I expected that because f ...
- asked by bdforbes (14 votes), answered by Mr.Wizard (8 votes)
—————————-
[What are the requirements for a well behaved indexed variable? Subscript, ToExpression, Downvalue?] (http://mathematica.stackexchange.com/questions/94294/what-are-the-requirements-for-a-well-behaved-indexed-variable-subscript-toexpr)
On writing this answer I needed to call a function, (NonlinearModelFit) with an unknown number of parameters.
We have learned that we should not use Subscript for indexing variables because ...
- asked by rhermans (14 votes), answered by Leonid Shifrin (14 votes)
—————————-
[What is wrong with RuleCondition here?] (http://mathematica.stackexchange.com/questions/94413/what-is-wrong-with-rulecondition-here)
Hold@1`5 /. x_Real :> RuleCondition[N@x, True] Hold@1`5 /. x_Real :> RuleCondition[N@2`5, True] Hold@2`5 /. x_Real :> RuleCondition[N@2`5, True] Hold@1`5 /. x_Real :> RuleCondition[N@t, ...
- asked by Chris Chiasson (12 votes), answered by Oleksandr R. (10 votes)
—————————-
[\(\tt AddTo\) regression in v10]( http://mathematica.stackexchange.com/questions/94296/tt-addto-regression-in-v10)
As we know we can assign special addition rules to symbols by using UpValues:
ClearAll[mySymbol] mySymbol /: mySymbol + x_ := {mySymbol, x}
They are used when we directly add something to mySymbol
...
- asked by jkuczm (12 votes), answered by Bob Hanlon (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Elegant operations on matrix rows and columns] (http://mathematica.stackexchange.com/questions/3069/elegant-operations-on-matrix-rows-and-columns)
Question
The Mathematica tutorial has a section ’Basic Matrix Operations’, describing operations like transpose, inverse and determinant. These operations all work on entire matrices. I am missing a ...
- asked by sjdh (90 votes), answered by Mr.Wizard (31 votes)
—————————-
[What are the most common pitfalls awaiting new users?] (http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users)
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by belisarius (266 votes), answered by Michael E2 (142 votes)
================================== Can you answer these? ==================================
[Interfacing Red Pitaya board with Mathematica] (http://mathematica.stackexchange.com/questions/94493/interfacing-red-pitaya-board-with-mathematica)
I just discovered the Red Pitaya board and borrowed a unit to play during this weekend. Surprisingly I did not find any reference to Mathematica on the Red Pitaya forum, nor did I find any reference ...
- asked by Christian Neel (6 votes)
—————————-
[Using NMaximize to get integer results for a fractional programming problem] (http://mathematica.stackexchange.com/questions/94549/using-nmaximize-to-get-integer-results-for-a-fractional-programming-problem)
I have an optimization problem that I am trying to model in mathematica (wolfram cloud, to be precise).
Link to notebook for code described here: ...
- asked by pyrex (3 votes)
—————————-
[How to speed up summing a large number of vectors] (http://mathematica.stackexchange.com/questions/94660/how-to-speed-up-summing-a-large-number-of-vectors)
First let me explain what I am trying to do in my code.
Assume that I send a very short chirp (2,000 ms long) into a domain filled with 20,000 particles randomly scattered in the domain.
The ...
- asked by Mahdi Razaz (3 votes)
================================== Top new questions this week: ==================================
[Mathematica 10.0.x freezes in Initializing kernels] (http://mathematica.stackexchange.com/questions/92931/mathematica-10-0-x-freezes-in-initializing-kernels)
I updated to Windows 10 and have been running Mathematica fine on it for over a month. For some reason, it has just stopped working. I don’t remember any Windows updates occurring which would have ...
- asked by mitcheljh (41 votes), answered by ilian (54 votes)
—————————-
[How to restore corrupted files?] (http://mathematica.stackexchange.com/questions/92814/how-to-restore-corrupted-files)
I have a file that I can’t reopen because MMa was "Not Responding" and I had to shut it down.
I found links online to this: http://support.wolfram.com/kb/12423
I executed those two instructions in a ...
- asked by Jerry Guern (13 votes), answered by Lou (11 votes)
—————————-
[No help from ?-command] (http://mathematica.stackexchange.com/questions/94165/no-help-from-command)
I recently upgraded to Mathematica 10.2, and there seem to be a problem with the help system. When typing
?Integrate
I get the following output
Integrate System` CreateUUID["Info-"] False False ...
- asked by mickep (12 votes), answered by ilian (11 votes)
—————————-
[Syntax for using Tooltip in DiscretePlot] (http://mathematica.stackexchange.com/questions/93990/syntax-for-using-tooltip-in-discreteplot)
Tooltip works fine in ListPlot:
ListPlot[Table[Tooltip[PDF[PoissonDistribution[10], x]], {x, 0, 20}]]
in which the decimal value of the distribution at a point is revealed when a cursor is placed ...
- asked by David G. Stork (10 votes), answered by march (10 votes)
—————————-
[Fast way to pass an array of integers to Java using JLink] (http://mathematica.stackexchange.com/questions/92878/fast-way-to-pass-an-array-of-integers-to-java-using-jlink)
I am using a package from java to compress a list of integers, this package provide me two methods, one for compress and other one for uncompress. Each of these methods has a version to int [] arrays ...
- asked by d555 (10 votes), answered by Leonid Shifrin (8 votes)
—————————-
[How to share a notebook?] (http://mathematica.stackexchange.com/questions/92848/how-to-share-a-notebook)
I have a folder in dropbox syncing to my desktop. I tried sharing a notebook file this way, but this generates lots of errors, conflicts, and data loss:
I have notebooks with Dynamic and other ...
- asked by M.R. (10 votes), answered by MarcoB (9 votes)
—————————-
[How do I remove roads from Mathematica maps?] (http://mathematica.stackexchange.com/questions/93976/how-do-i-remove-roads-from-mathematica-maps)
I’m using GeoGraphics and Polygon[Interpreter["USState"]["Colorado"]] to create a map of Colorado and several bordering states. With automatic GeoStyling, I get a decent map with cities and roads ...
- asked by mmta no0b (9 votes), answered by Chip Hurst (17 votes)
================================== Greatest hits from previous weeks: ==================================
[Alternatives to Mathematica] (http://mathematica.stackexchange.com/questions/28162/alternatives-to-mathematica)
Inspired by the recent question Alternatives to LaTeX (currently 58 upvotes) on http://tex.stackexchange.com/
Are there any paid-for or open source alternatives to Mathematica which produce equal or ...
- asked by akk (28 votes), answered by Sumit (18 votes)
—————————-
[What are the most common pitfalls awaiting new users?] (http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users)
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by belisarius (264 votes), answered by Michael E2 (141 votes)
================================== Can you answer these? ==================================
[Help nedeed for understanding NDSolve architecture -Vacuum Heating Simulation] (http://mathematica.stackexchange.com/questions/94163/help-nedeed-for-understanding-ndsolve-architecture-vacuum-heating-simulation)
I am a beginner in mathematica and I am facing a problem that is way bigger than my knowledge..
I am tryng to simulate a semplificated version of Brunel Effect, wich is a Laser-Plasma interaction ...
- asked by Cosimo (2 votes)
—————————-
[Strange behavior of autocomplete for ColorData] (http://mathematica.stackexchange.com/questions/94135/strange-behavior-of-autocomplete-for-colordata)
I’m seeing very weird behavior when autocompleting:
Not sure if this is a bug. Is it?
(I have OSX v10.2)
- asked by M.R. (5 votes)
—————————-
[Open file menu bug with ubuntu dark theme] (http://mathematica.stackexchange.com/questions/92825/open-file-menu-bug-with-ubuntu-dark-theme)
I’m using Mathematica on a Ubuntu with a dark theme. When I click on the open file menu option, it shows up with a white background and white letters. I can only see something if the folder or file is ...
- asked by Hugo Andrade (3 votes)
================================== Top new questions this week: ==================================
[Advice for Mathematica as Mathematician’s Aid] (http://mathematica.stackexchange.com/questions/92686/advice-for-mathematica-as-mathematicians-aid)
I use Mathematica mainly as an aid in symbolic attacks on problems, usually intermediate or harder and often number theoretic. While Reduce, Simplify, et al. are remarkably powerful, they of course ...
- asked by CarlEdman (29 votes), answered by MarcoB (20 votes)
[How can I evaluate untrusted Mathematica code in a sandbox?] (http://mathematica.stackexchange.com/questions/92347/how-can-i-evaluate-untrusted-mathematica-code-in-a-sandbox)
Is there any way to build a sandbox to evaluate untrusted Mathematica expressions in order to prevent them from having (malicious or accidental) harmful side effects?
Context: I’m developing a system ...
- asked by ibeatty (21 votes), answered by Stefan R (10 votes)
[Efficient lazy weak compositions] (http://mathematica.stackexchange.com/questions/92647/efficient-lazy-weak-compositions)
In Mathematica all weak k-compositions of integer n can be generated using permutations of integer partitions:
ClearAll[weakCompositionsPermPart] weakCompositionsPermPart[n_Integer, ...
- asked by jkuczm (19 votes), answered by jkuczm (18 votes)
[SeriesData sucks when it can. How do I keep SeriesData from sucking?] (http://mathematica.stackexchange.com/questions/92646/seriesdata-sucks-when-it-can-how-do-i-keep-seriesdata-from-sucking)
When I run
Series[f[x]*Sin[x],{x,0,3}, Analytic->False] I get: f[x](x-x^3/3+O[x]^4) as expected. In FullForm, this is Times[f[x],SeriesData[x,0,List[1,0,Rational[-1,6]],1,4,1]] But ...
- asked by QuantumDot (16 votes)
[How to zero (or replace) the diagonal of a square matrix?] (http://mathematica.stackexchange.com/questions/92666/how-to-zero-or-replace-the-diagonal-of-a-square-matrix)
Zeroing the diagonal of a square matrix is an operation I need frequently, but somehow I still haven’t managed to find an elegant solution that satisfies all these requirements:
works with both ...
- asked by Szabolcs (14 votes), answered by ciao (12 votes)
[Splitting a list into increasing sublists] (http://mathematica.stackexchange.com/questions/92527/splitting-a-list-into-increasing-sublists)
I have a list of numbers (say, for example, 1,2,3,4,3,2,1,2,3,4,3,2), and I want to split it into sublists so that each sublist is the (smallest) sublist whose sum is larger than the preceding one. ...
- asked by rogerl (14 votes), answered by Chris Degnen (4 votes)
[How to detect loops in a vector field?] (http://mathematica.stackexchange.com/questions/92425/how-to-detect-loops-in-a-vector-field)
Given a vector field and I’d like to detect if there are streamlines in closed patterns. For example, if the input is a vector field like this:
image = ColorConvert[Rasterize[\[Infinity], ImageSize ...
- asked by M.R. (14 votes), answered by nikie (19 votes)
================================== Greatest hits from previous weeks: ==================================
[Understanding differences between Maple and Mathematica in examples picked by Maplesoft] (http://mathematica.stackexchange.com/questions/60124/understanding-differences-between-maple-and-mathematica-in-examples-picked-by-ma)
I am reading the document How Maple Compares to Mathematica. On page 15 there is an example where Mathematica produces wrong results. Does anybody know why?
MAPLE:
MATHEMATICA:
Also on page 17 ...
- asked by mrz (31 votes), answered by Mr.Wizard (37 votes)
[How to express trigonometric equation in terms of of given trigonometric function?] (http://mathematica.stackexchange.com/questions/434/how-to-express-trigonometric-equation-in-terms-of-of-given-trigonometric-functio)
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
Sin[x]^2+Cos[x]^2==1 Sin[x]/Cos[x]==Tan[x] ...
- asked by Prashant Bhate (23 votes), answered by Simon (27 votes)
================================== Can you answer these? ==================================
[Creating a certain image (3D shadows, highlighted intersections)] (http://mathematica.stackexchange.com/questions/92494/creating-a-certain-image-3d-shadows-highlighted-intersections)
I would like to learn how to code within Mathematica the following picture:
I tried using
planarShadow[x_, direction_, normal_, darkShadow_: True] := Module[{d, n}, d = Normalize[direction]; ...
- asked by boldbrandywine (5 votes)
[How to stop auto loading of previously opened notebooks] (http://mathematica.stackexchange.com/questions/92699/how-to-stop-auto-loading-of-previously-opened-notebooks)
I’m trying to prevent Mathematica from opening previously opened notebooks when I start it up. I’m using version 10.0.0.0 on Mac OS X Yosemite. I’ve dug around in the preferences, and have tried ...
- asked by Peter Wills (2 votes)
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[Visualising a 1-(50,15,15) design] (http://mathematica.stackexchange.com/questions/92605/visualising-a-1-50-15-15-design)
The problem I have is the visualisation of a \(1-(50,15,15)\) design. That is a set of \(50\) points and \(50\) blocks (lines), so that each point is on \(15\) lines, and each line contains \(15\) points.
My ...
- asked by user32681 (4 votes)
================================== Top new questions this week: ==================================
[Strange behavior with Cases and Position with SetDelayed] (http://mathematica.stackexchange.com/questions/91917/strange-behavior-with-cases-and-position-with-setdelayed)
I feel like I must be missing something simple and obvious here, but this has me scratching my head.
This works as expected:
list = {f[a], f[b]}; Cases[list, f[x_] :> x] -> Position[list, ...
- asked by rhennigan (16 votes), answered by Leonid Shifrin (15 votes)
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[Scraping High-Res images from the MoMA and the Van Gogh Museum websites]( http://mathematica.stackexchange.com/questions/91982/scraping-high-res-images-from-the-moma-and-the-van-gogh-museum-websites)
Many art websites allow the user to zoom into an image to see it at high resolution by using image tiles. It is great on the website, but presents problems if one wishes to compile a complete high ...
- asked by martin (13 votes), answered by belisarius (16 votes)
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[best practices for saving Datasets and TemporalData to a SQL database] (http://mathematica.stackexchange.com/questions/92020/best-practices-for-saving-datasets-and-temporaldata-to-a-sql-database)
I have been working with a simulation tool that generates large volumes of data, and it’s time to start saving this to a proper database. Is there an established mechanism for saving TemporalData ...
- asked by Michael Stern (12 votes), answered by Leonid Shifrin (6 votes)
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[How to determine if a function is continuous?] (http://mathematica.stackexchange.com/questions/91877/how-to-determine-if-a-function-is-continuous)
I wish to write code for Riemann Stieltjes integrals in Mathematica.
A necessary condition for the theorem to hold is that the function must be continuous. The domain of the function is a closed ...
- asked by Katherine (12 votes)
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[How to service preemptive computations while running a LibraryLink function?] (http://mathematica.stackexchange.com/questions/91893/how-to-service-preemptive-computations-while-running-a-librarylink-function)
Cross-posted to Wolfram Community
The following is from the comparison between WSTP (MathLink) and LibraryLink in the documentation:
When the Wolfram Language is waiting for a WSTP application ...
- asked by Szabolcs (11 votes)
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[Why does this LibraryLink example of LinkObject based passing not work? Bug or user error?] (http://mathematica.stackexchange.com/questions/92047/why-does-this-librarylink-example-of-linkobject-based-passing-not-work-bug-or-u)
There’s an example of LinkObject-based passing in the LibraryLink documentation. Unfortunately the cell in the documentation notebook is corrupted, but to skip that problem I’m going to reproduce it ...
- asked by Szabolcs (9 votes), answered by ilian (6 votes)
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[Form of citation for data via Wolfram Mathematica] (http://mathematica.stackexchange.com/questions/92179/form-of-citation-for-data-via-wolfram-mathematica)
What citation or reference should I adhere to if I’m using curated data obtained via Mathematica? I’m talking about data, or eg. plots thereof, obtained using functions such as SatelliteData, ...
- asked by zentient (9 votes), answered by V-J (5 votes)
================================== Greatest hits from previous weeks: ==================================
[Generating visually pleasing circle packs] (http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs)
EDIT: (my conclusion and thank you note) I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you had fun and enjoyed it the same as I did.
I would like to ...
- asked by VividD (80 votes), answered by level1807 (49 votes)
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[What are the most common pitfalls awaiting new users?] (http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users)
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by belisarius (263 votes), answered by Michael E2 (139 votes)
================================== Can you answer these? ==================================
[Intersecting RegionPlots] (http://mathematica.stackexchange.com/questions/92252/intersecting-regionplots)
Does the Mathematica graphics system have any concept of intersecting regionplots? I’ve found about intersecting graphics but not regionplots so far. For example, if I want to show the intersection of ...
- asked by Elsa (3 votes)
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[MathLink (WSTP) vs LibraryLink performance] (http://mathematica.stackexchange.com/questions/91887/mathlink-wstp-vs-librarylink-performance)
Has anyone benchmarked LibraryLink vs MathLink when passing large arrays?
Specifically I would like to know how performance compares when using the following to pass and return a large array:
...
- asked by Szabolcs (6 votes)
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[Issues adding properties to multigraph] (http://mathematica.stackexchange.com/questions/92014/issues-adding-properties-to-multigraph)
Today I was working with a large multi-graph with properties on the edges when I discovered that properties aren’t assigned as expected.
My preferred graph construction method is to specify ...
- asked by Martin John Hadley (2 votes)
================================== Top new questions this week: ==================================
[Given an exact formula, how can Mathematica find a probability distribution whose PDF matches it?](http://mathematica.stackexchange.com/questions/91408/given-an-exact-formula-how-can-mathematica-find-a-probability-distribution-whos)
So, given some data, Mathematica 10.2 can now attempt to figure out what probability distribution might have produced it. Cool! But suppose that, instead of having data, we have something that is in ...
- asked by Seth Chandler (19 votes), answered by Vitaliy Kaurov (12 votes)
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[Improving speed of code computing number of nonrepeating partitions] (http://mathematica.stackexchange.com/questions/91613/improving-speed-of-code-computing-number-of-nonrepeating-partitions)
I need to answer the following for a number of parameters: How many ways can the integer \(k\) be written as a sum of \(n\) different integers ranging from \(1\) to \(m\)?
My initial attempt was the ...
- asked by jorgen (16 votes), answered by ciao (14 votes)
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[Implementing the PCG random number generator] (http://mathematica.stackexchange.com/questions/91497/implementing-the-pcg-random-number-generator)
PCG ("permuted congruential generator") is a recently-introduced random number generator.
PCG is a family of simple fast space-efficient statistically good algorithms for random number generation. ...
- asked by blochwave (15 votes), answered by Guess who it is. (13 votes)
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[Use Compile to improve performance] (http://mathematica.stackexchange.com/questions/91787/use-compile-to-improve-performance)
I’ve recently discovered Compile as a way to optimize my code. I wrote a program to learn something new about Compile. I have a function that creates a vector in the following form:
...
- asked by Vanille (14 votes), answered by halirutan (19 votes)
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[Why does’t SeedRandom work here?] (http://mathematica.stackexchange.com/questions/91523/why-doest-seedrandom-work-here)
From the docs on SeedRandom,
SeedRandom[] resets the generator, using as a seed the time of day and certain attributes of the current Wolfram System session.
This means that every time I use ...
- asked by Szabolcs (14 votes), answered by Mr.Wizard (2 votes)
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[How to implement a more efficient inverse triangular recursion?] (http://mathematica.stackexchange.com/questions/91610/how-to-implement-a-more-efficient-inverse-triangular-recursion)
Consider the following inverse triangular formula
$$\left( \begin{array}{ccccc} & & & & N_{i-p,p}\left(u_0\right) \\ & & N_{i-2,2}\left(u_0\right) & &
- asked by Shutao Tang (11 votes), answered by xzczd (7 votes)
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[Nearest Kronecker Product] (http://mathematica.stackexchange.com/questions/91651/nearest-kronecker-product)
Some people (see The ubiquitous Kronecker product by Van Loan) have worked on finding two matrices \(\mathbf A\),\(\mathbf B\) of specified size whose tensor product \(\mathbf A\otimes \mathbf B\) is closest ...
- asked by pdmclean (10 votes), answered by Guess who it is. (10 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make use of Associations?] (http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations)
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (87 votes), answered by Leonid Shifrin (96 votes)
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[3D surface that looks like a virus] (http://mathematica.stackexchange.com/questions/74193/3d-surface-that-looks-like-a-virus)
I have been recently using Mathematica for composing animations that are part of the supplementary information of my papers.
I am currently trying to build an animation that involves a viral ...
- asked by user2098 (16 votes), answered by Chris Degnen (18 votes)
================================== Can you answer these? ==================================
[Restarting random number generators where you left off] (http://mathematica.stackexchange.com/questions/91612/restarting-random-number-generators-where-you-left-off)
I have code that uses both RandomReal and RandomInteger a number of times to produces a sequence of \(n\) data sets. After closing the notebook and quitting the kernel, I would like to be able to start ...
- asked by user26718 (7 votes)
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[Swinging Beam example from Help. Not Understanding/Not Working] (http://mathematica.stackexchange.com/questions/91393/swinging-beam-example-from-help-not-understanding-not-working)
To help me understand finite element analysis with Mathematica I have been reading the Finite Element Method User Guide in Help and am stuck on the example in Coupled PDEs. Here there is a static beam ...
- asked by Hugh (2 votes)
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[Mathematica 10 Audio Export Issue] (http://mathematica.stackexchange.com/questions/91649/mathematica-10-audio-export-issue)
Summary of the problem: When exporting data as an audio file (AIFF/WAV etc.), there appears to be unwanted scaling and offset in the data such that the minimum and maximum values are forced to be -1 ...
- asked by Rahul (2 votes)
================================== Top new questions this week: ==================================
[Listable compiled function crashes the kernel with "no more memory available"] (http://mathematica.stackexchange.com/questions/90081/listable-compiled-function-crashes-the-kernel-with-no-more-memory-available)
Bug introduced in 9.0.0 and persisting through 10.2.0
I am trying to speed up a function that involves continued fractions. Since ContinuedFraction cannot be compiled and the alternative way with ...
- asked by shrx (16 votes)
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[Can Mathematica Export Shapefiles?] (http://mathematica.stackexchange.com/questions/90063/can-mathematica-export-shapefiles)
Mathematica is great at importing ESRI shapefiles (.shp).
Import["http://exampledata.wolfram.com/usamap.zip", "Graphics"]
But it seems like it’s a glaring omission that it can’t export them. ...
- asked by kale (16 votes), answered by kale (21 votes)
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[Integration of a PDE solution over a custom-defined subdomain] (http://mathematica.stackexchange.com/questions/90094/integration-of-a-pde-solution-over-a-custom-defined-subdomain)
Preamble: In my previous question I raised a problem of a custom-chosen integration of the solution of a PDE. In that case it was an integration along a line lying within the PDE domain. The solution ...
- asked by Alexei Boulbitch (11 votes), answered by Michael E2 (6 votes)
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[Detect if code is running in the cloud] (http://mathematica.stackexchange.com/questions/91202/detect-if-code-is-running-in-the-cloud)
Wolfram offers several services for running code in the cloud: Mathematica Online, Programming Cloud, CloudEvaluate, etc.
How can a piece of code detect if it is being run in the cloud or the ...
- asked by Szabolcs (11 votes), answered by Leonid Shifrin (10 votes)
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[Fastest way to sum the upper triangle] (http://mathematica.stackexchange.com/questions/90067/fastest-way-to-sum-the-upper-triangle)
I feel like this is an recurring question: if there’s a symmetric matrix whose diagonal is not all 0, how could I get the sum of the part of it that’s above the diagonal as fast as possible?
Small ...
- asked by arax (10 votes), answered by MarcoB (3 votes)
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[Possible bug in VonMisesDistribution?] (http://mathematica.stackexchange.com/questions/90019/possible-bug-in-vonmisesdistribution)
Observe:
FullSimplify[PDF[VonMisesDistribution[\[Mu], 0], x], (((-Pi + \[Mu] & )*lt; ) = (x & )*lt; ) = Pi + \[Mu]] == FullSimplify[PDF[UniformDistribution[{\[Mu] - Pi, \[Mu] + Pi}], x], (((-Pi + \[Mu] & )*lt; ) = (x & )*lt; ) = Pi + \[Mu]] (* True *)
...
- asked by ciao (10 votes), answered by Karsten 7. (7 votes)
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[Faster position-based duplicate removal in a ragged array?]
Take a ragged 2D array:
rArray=4, 2, 1, 0, 2, 2, 0, 0, 3, 3, 3, 4, 0, 3, 4
I need to "deduplicate" this, where a duplicate is any element of a sublist where that element exists at the ...
- asked by ciao (9 votes), answered by sakra (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How to ask Mathematica to imitate Andy Warhol’s pop-art painting?] (http://mathematica.stackexchange.com/questions/59132/how-to-ask-mathematica-to-imitate-andy-warhols-pop-art-painting)
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
- asked by Putterboy (43 votes), answered by belisarius (50 votes)
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[How to find the position of elements in a list satisfying criteria] (http://mathematica.stackexchange.com/questions/180/how-to-find-the-position-of-elements-in-a-list-satisfying-criteria)
Say I have a list x=2,4,6,8,10 and I want to find out the positions of the elements that are greater than 7.
Select[x, #>7&]
gives the elements themselves, and Position[x,8] gives the
...
- asked by PeterR (25 votes), answered by Guess who it is. (19 votes)
================================== Can you answer these? ==================================
[Mathematica package for explicit matrix representations of group generators?] (http://mathematica.stackexchange.com/questions/89964/mathematica-package-for-explicit-matrix-representations-of-group-generators)
While there are several packages that are capable of working with weights and roots (for example LieArt), I couldn’t find any package that spits out explicit matrices for the generators, for example ...
- asked by JakobH (4 votes)
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[Mathematica claiming two Weierstrass half-periods not independent] (http://mathematica.stackexchange.com/questions/91322/mathematica-claiming-two-weierstrass-half-periods-not-independent)
I have the following code:
f[x_, y_, p_] = (p*(E^(Pi/y)*x + 2*x*Cosh[(2*Pi*x)/y] - 2*Sinh[(2*Pi*x)/y]))/(y*(E^(Pi/y) + 2*Cosh[(2*Pi*x)/y])); y1 = 1/11; t1 = I*y1; p1 = 1; xf = ...
- asked by spietro (1 vote)
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[Solving for the roots of a trilinear system of polynomials] http://mathematica.stackexchange.com/questions/91254/solving-for-the-roots-of-a-trilinear-system-of-polynomials
I have been trying to solve for the roots of the following system of trilinear polynomials:
eq1 = a6 x y + a5 x z + a4 y z + a3 x + a2 y + a1 z + a0; eq2 = x y z + b6 x y + b5 x z + b4 y z + b3 x + ... - asked by Kagaratsch (2 votes)
================================== Top new questions this week: ==================================
[Upgrade to Windows 10] http://mathematica.stackexchange.com/questions/89407/upgrade-to-windows-10
Can users of Mathematica on Windows 7 or Windows 8/8.1 upgrade their computers to Windows 10 a process that began today? Does Mathematica work? Are all the settings, licenses, access to files and ...
- asked by Lubos Motl (23 votes), answered by RunnyKine (21 votes)
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[Solve slower in versions 9 and 10] http://mathematica.stackexchange.com/questions/89650/solve-slower-in-versions-9-and-10
With some systems of equations, Solve is much slower in versions 9 and 10 than in earlier versions, apparently because it is doing more simplification of the results.
With the following example ...
- asked by Simon Rochester (21 votes), answered by Michael E2 (11 votes)
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[Speeding up the built-in Rudin-Shapiro and Thue-Morse sequence functions] http://mathematica.stackexchange.com/questions/89345/speeding-up-the-built-in-rudin-shapiro-and-thue-morse-sequence-functions
Version 10.2 introduced two well-studied sequences as functions: the (Golay-)Rudin-Shapiro sequence (RudinShapiro[]) and the (Prouhet-)Thue-Morse sequence (ThueMorse[]). Since these functions are ...
- asked by Guess who it is. (19 votes), answered by Oleksandr R. (22 votes)
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[Change in Lighting and Show in V10?] http://mathematica.stackexchange.com/questions/89491/change-in-lighting-and-show-in-v10
According the documentation for Show:
Options explicitly specified in Show override those included in the graphics expression. The lists of non-default options in the Subscript[g, i] are ...
- asked by Michael E2 (13 votes), answered by Mr.Wizard (7 votes)
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[Global‘ context not empty at startup in v10.2.0] http://mathematica.stackexchange.com/questions/89686/global-context-not-empty-at-startup-in-v10-2-0
Bug introduced in 10.2 and persisting through 10.2 or later
Note that the analysis of this problem revealed a different problem than in Potential pollution of Global‘ context in fresh kernel (see ...
- asked by Chen Stats Yu (12 votes), answered by Michael E2 (8 votes)
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[How to monitor the progress of training a classifier?] http://mathematica.stackexchange.com/questions/89444/how-to-monitor-the-progress-of-training-a-classifier
I've had p = Predict[x -> y] running for hours and I have now idea if I should kill it or not. I'm looking for some rough bounds for an estimate of how long Predict[] or Classify[] will take to ...
- asked by M.R. (12 votes), answered by Sebastian (12 votes)
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[All value types for a symbol?] http://mathematica.stackexchange.com/questions/89607/all-value-types-for-a-symbol
Robby Villegas here shows a nice way to see all the types associated with a symbol. He sets a symbol, valueTypes, to an explicit list of the values types in version 3.0 of Mathematica (I took off his ...
- asked by Reb.Cabin (11 votes), answered by Reb.Cabin (6 votes)
================================== Greatest hits from previous weeks: ==================================
[How to perform a multi-peak fitting?] http://mathematica.stackexchange.com/questions/26336/how-to-perform-a-multi-peak-fitting
I am wondering how to implement the multi-peak detecting and fitting in Mathematica. Following is an example of fitting the data using three peaks (such that the data peak1 + peak2 + peak3).
The ...
- asked by Everett You (27 votes), answered by Silvia (29 votes)
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[Get a "step-by-step" evaluation in Mathematica] http://mathematica.stackexchange.com/questions/148/get-a-step-by-step-evaluation-in-mathematica
Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?
...
- asked by Skydreamer (75 votes), answered by Guess who it is. (61 votes)
================================== Can you answer these? ==================================
[Fast Partition of list at depth 2] http://mathematica.stackexchange.com/questions/89809/fast-partition-of-list-at-depth-2
I am looking to partition a list up at a certain depth level. Following code should demonstrate what I mean:
test = Table[Random[], {1000}, {32}, {32}]; result = Map[Partition[#, {5, 5}, 1] &, ...
- asked by Julian Francis (6 votes)
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[ListLogPlot error when forcing y axes start at 0] http://mathematica.stackexchange.com/questions/89524/listlogplot-error-when-forcing-y-axes-start-at-0
I came across an error I can not circumvent.
When plotting the following:
ListLogPlot[Table[1/x, {x, 1, 100}]]
I receive a functioning plot. If I now want to add a specific PlotRange, i.e.
...
- asked by mondo (4 votes)
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[DSolve returns an answer that is not a solution] http://mathematica.stackexchange.com/questions/89550/dsolve-returns-an-answer-that-is-not-a-solution
Investigating DSolve misses a solution of a differential equation, I came across this odd behavior of DSolve.
The following DSolve command returns an answer to the ODE but the solutions do not ...
- asked by Michael E2 (5 votes)
================================== Top new questions this week: ==================================
[A With expression local variable specification without head List] http://mathematica.stackexchange.com/questions/88920/a-with-expression-local-variable-specification-without-head-list
I just noticed a new form of With in its documentation:
With[$x=x_0$, $expr$]
specifies that all occurrences of the symbol \(x\) in \(expr\) should be replaced by \(x_0\).
Note the lack of braces ...
- asked by jkuczm (17 votes), answered by Itai Seggev (9 votes)
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[New AssociationThread forms in 10.2?] http://mathematica.stackexchange.com/questions/88940/new-associationthread-forms-in-10-2
Is this another case of "documented" but "not implemented" ? or at least it is not explained clearly as I cannot make it work:
Two new forms appears in the new 10.2 doc. of AssociationThread (the ...
- asked by SquareOne (17 votes)
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[Visualizing Type System Operations] http://mathematica.stackexchange.com/questions/89080/visualizing-type-system-operations
With the introduction of Dataset in version 10, Mathematica acquired a static type-checking subsystem. A fair number of dataset-related questions here on MSE concern the operation of that type ...
- asked by WReach (16 votes), answered by WReach (16 votes)
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[Dataset seems to break Information] http://mathematica.stackexchange.com/questions/89036/dataset-seems-to-break-information
Bug present in version 10.2
My little function, from pre-10.2 ,to turn a headed table into a Dataset. toDataset[table_List] := Dataset@(Association /@ (Function[r, Thread[First[r] -> #] ...
- asked by Ymareth (16 votes), answered by WReach (14 votes)
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[Initial values in Manipulate are hijacked by existing global variable values] http://mathematica.stackexchange.com/questions/89108/initial-values-in-manipulate-are-hijacked-by-existing-global-variable-values
Is the following behaviour a bug? It's the same in all versions between 9.0-10.2.0. Let's try this simple Manipulate with the initial value of a set to 1: Manipulate[Style[a, Large], {{a, 1}, 0, ...
- asked by Szabolcs (13 votes)
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[Undocumented fourth parameter of Collect; how long has it been there?] http://mathematica.stackexchange.com/questions/88781/undocumented-fourth-parameter-of-collect-how-long-has-it-been-there
While tinkering with How to get a list of monomials of a polynomial without coefficients? on a whim I tried a fourth argument in Collect and found:
Collect[(x + y + z + 1)^2, {x, y}, foo, bar]
...
- asked by Mr.Wizard (13 votes)
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[How can we show the boundary of a WordCloud shape?] http://mathematica.stackexchange.com/questions/88846/how-can-we-show-the-boundary-of-a-wordcloud-shape
WordCloud can arrange the words inside a shape. data = EntityValue[CountryData[], {"Name", "Population"}]; WordCloud[data, Disk[], WordOrientation -> "Random", Frame -> True]
As you can see ...
- asked by Szabolcs (12 votes), answered by Sjoerd C. de Vries (12 votes)
================================== Greatest hits from previous weeks: ==================================
Parallel and perpendicular symbol from Mathematica to LaTeXhttp://mathematica.stackexchange.com/questions/46538/parallel-and-perpendicular-symbol-from-mathematica-to-latex
I want to get the following expression from Mathematica to LaTeX\[ \begin {bmatrix} E_{\parallel } \\ E_{\perp } \end {bmatrix} \] I have tried to use inbuilt ’symbol’ character from the special ...
- asked by Steve Hatcher (4 votes), answered by Sjoerd C. de Vries (9 votes)
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[Generating visually pleasing circle packs] http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs
EDIT: (my conclusion and thank you note) I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you had fun and enjoyed it the same as I did.
I would like to ...
- asked by VividD (79 votes), answered by level1807 (49 votes)
================================== Can you answer these? ==================================
[Call library function in compile] http://mathematica.stackexchange.com/questions/89134/call-library-function-in-compile
On the Wolfram official website, there is an example of calling library function in a compiled function:
Needs["CompiledFunctionTools`"]
...
- asked by xslittlegrass (2 votes)
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[MMA breaks down when DSolve -ing a third-order linear ODE] http://mathematica.stackexchange.com/questions/88862/mma-breaks-down-when-dsolve-ing-a-third-order-linear-ode
My code is:
DSolve[y'''[x] + (x^3 + a^3) y[x] == 0, y[x], x] It should be noted that similar code not only meets the similar problem but also returns more warning messages: DSolve[y'''[x] + (x^3 ...
- asked by WateSoyan (9 votes)
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[HistogramList is much Slower in 10.2 vs 10.1] http://mathematica.stackexchange.com/questions/88992/histogramlist-is-much-slower-in-10-2-vs-10-1
While I was running a code I wrote using version 10.1, I noticed that in version 10.2 the running time of the same code was more than twice as long. After some digging, I figured out the culprit is ...
- asked by RunnyKine (10 votes)
================================== Top new questions this week: ==================================
[How do I remove grid from this photo?] http://mathematica.stackexchange.com/questions/88494/how-do-i-remove-grid-from-this-photo
I found this cat a month ago, and I’m not his owners’ friend so the mosquito grid was the inevitable problem. I would like to post-process this photo to get rid of it, but I don’t know exactly how ...
- asked by Nakilon (19 votes), answered by nikie (33 votes)
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[What is behind Mathematica’s experimental ‘FindFormula‘ function?] http://mathematica.stackexchange.com/questions/88511/what-is-behind-mathematicas-experimental-findformula-function
In version 10.2 there is a new experimental function: FindFormula.
I suspect that a genetic programming algorithm (symbolic regression) is behind this new feature but I can’t find any references.
My ...
- asked by vonjd (18 votes)
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[Is there a GraphicsPrimitiveQ (or a complete list of Heads of graphics primitives)?] http://mathematica.stackexchange.com/questions/88342/is-there-a-graphicsprimitiveq-or-a-complete-list-of-heads-of-graphics-primitive
For various reasons related to workflow associated with creating figures for journals, I am creating functions that will accept graphics primitives and a set of options and spit out a Graphics object ...
- asked by march (16 votes), answered by rcollyer (13 votes)
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[Symbolic area calculation for a parametric self-intersecting closed curve] http://mathematica.stackexchange.com/questions/88623/symbolic-area-calculation-for-a-parametric-self-intersecting-closed-curve
The parametric equation of the curve is:
\[\begin {cases} x &= -9 \sin (2 t)-5 \sin (3 t) \\[6pt] y & = 9 \cos (2 t)-5 \cos (3 t) \end {cases}\quad t\in [0,2\pi ]\]
which can be easily ...
- asked by LCFactorization (13 votes), answered by belisarius (21 votes)
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[What’s the point of ContainsAll, ContainsAny and friends?] http://mathematica.stackexchange.com/questions/88295/whats-the-point-of-containsall-containsany-and-friends
Mathematica 10.2 contains a few new functions that test set containment: ContainsAll, ContainsAny and a few others. The documentation mentions that these are equivalent to existing functions like ...
- asked by nikie (12 votes)
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[10.2 Dataset extraneous print using Transpose] http://mathematica.stackexchange.com/questions/88238/10-2-dataset-extraneous-print-using-transpose
Introduced in 10.2, fixed by paclet update (GeneralUtilities 10.2.1).
This is probably patch code in 10.2. Is there a way to turn off print with Transpose?
ds = <|"k1" -> <|"a" -> 1, ...
- asked by alancalvitti (11 votes), answered by Michael E2 (12 votes)
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[What will happen if I set ExclusionsStyle for points in 2D plot?] http://mathematica.stackexchange.com/questions/88479/what-will-happen-if-i-set-exclusionsstyle-for-points-in-2d-plot
For example
f[x_] := (x^5 - 4 x^2 + 1)/(x - 1/2); Plot[f[x], {x, -1, 2}, Exclusions -> {f[x] == 0}, ExclusionsStyle -> Dashed]
Has the ExclusionsStyle ->
Dashed option done anything ...
- asked by xzczd (11 votes), answered by xzczd (13 votes)
================================== Greatest hits from previous weeks: ==================================
[No weekends please] http://mathematica.stackexchange.com/questions/78735/no-weekends-please
I need to get the DateValues of the last 30 days (starting from yesterday, not today!) excluding saturdays and sundays. I want that the dates are german time (GMT + 1). The only solution I have found ...
- asked by eldo (4 votes), answered by Pickett (12 votes)
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[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (18 votes), answered by Artes (14 votes)
================================== Can you answer these? ==================================
[RegionPlot, RegionPlot3D and differing embedding dimensions] http://mathematica.stackexchange.com/questions/88584/regionplot-regionplot3d-and-differing-embedding-dimensions
RegionPlot seems to be for plotting regions with an embedding dimensions of 2 only, and RegionPlot3D for regions with an embedding dimensions of 3.
Yet passing a region of the wrong embedding ...
- asked by Szabolcs (5 votes)
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[How can I force the use of sparse diagonalization methods?] http://mathematica.stackexchange.com/questions/88551/how-can-i-force-the-use-of-sparse-diagonalization-methods
When I evaluate the Eigenvalues function on a very large (e.g. 2^16 x 2^16) sparse matrix, Mathematica says something like:
Because finding 65536 out of the 65536 eigenvalues and/or eigenvectors ...
- asked by P.R. (4 votes)
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[How to Copy formatted code without backslashes added?] http://mathematica.stackexchange.com/questions/88539/how-to-copy-formatted-code-without-backslashes-added
By default code copied from the FrontEnd is formatted with backslashes added at the ends of lines. For example, evaluating in a Notebook
Range[40]
and copying the output produces the following when ...
- asked by Alexey Popkov (9 votes)
================================== Top new questions this week: ==================================
[New behavior of PlotRange in Mathematica 10] http://mathematica.stackexchange.com/questions/87808/new-behavior-of-plotrange-in-mathematica-10
In Mathematica 10, when I plot data that has small changes around some non-zero value, the plot chooses a PlotRange that "collapses" the data so that the variations cannot be seen. The only way I can ...
- asked by Greg Cook (17 votes), answered by Mr.Wizard (13 votes)
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[Simple Matrix multiplication takes very long] http://mathematica.stackexchange.com/questions/87857/simple-matrix-multiplication-takes-very-long
Bug introduced in 10.1.0
I came across some strange behaviour during a computation involving matrices with symbolic values. It is reproduced below.
Multiplying a random 30x30 array with symbolic ...
- asked by A. Roy (14 votes)
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[Why does leaving and re-entering a context lose values defined in that context?] http://mathematica.stackexchange.com/questions/88147/why-does-leaving-and-re-entering-a-context-lose-values-defined-in-that-context
I’m getting unexpected behavior when beginning a new context, leaving it, and then re-entering it. Specifically, when re-entering the context, symbols that had been previously defined in that context ...
- asked by ibeatty (12 votes), answered by Simon Rochester (13 votes)
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[Use of Key to extract a key value in Associations not working in V10.1] http://mathematica.stackexchange.com/questions/88034/use-of-key-to-extract-a-key-value-in-associations-not-working-in-v10-1
V10.1:
<|a -> 1|>[Key @ a] (* Missing["KeyAbsent", Key[a]]*) V10.0: <|a -> 1|>[Key @ a] (* 1 *)
Bug or Design Change?
- asked by Ronald Monson (11 votes), answered by Szabolcs (8 votes)
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[Using Mathematica to solve a probability problem] http://mathematica.stackexchange.com/questions/88178/using-mathematica-to-solve-a-probability-problem
The problem is from Principles of Statistics by M.G. Bulmer:
In a certain survey of the work of chemical research workers, it was found, on the basis of extensive data, that on average each man ...
- asked by billc (10 votes), answered by ciao (11 votes)
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[What does this message mean and how serious is it?] http://mathematica.stackexchange.com/questions/87891/what-does-this-message-mean-and-how-serious-is-it
I had some Mathematica files on over which recently I have faced to this message:
However, after searching, I have seen some blogs in Mathematica SE or in somewhere else about that, but I could not ...
- asked by mr.0093 (9 votes), answered by Mr.Wizard (17 votes)
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[Remove static objects from an image sequence] http://mathematica.stackexchange.com/questions/87901/remove-static-objects-from-an-image-sequence
Is it possible to remove static objects/pixels from a sequence of images?
Lets say I have a black square in the middle of my white picture (white background) and a black circle is orbiting around it. ...
- asked by PH13 (9 votes), answered by Pickett (6 votes)
================================== Greatest hits from previous weeks: ==================================
[Multivariable Taylor expansion does not work as expected] http://mathematica.stackexchange.com/questions/15023/multivariable-taylor-expansion-does-not-work-as-expected
The basic multivariable Taylor expansion formula around a point is as follows:
\[ f(\mathbf r + \mathbf a) = f(\mathbf r) + (\mathbf a \cdot \nabla )f(\mathbf r) + \frac {1}{2!}(\mathbf a \cdot \]
- asked by matheorem (15 votes), answered by Jens (21 votes)
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[How to ask Mathematica to imitate Andy Warhol’s pop-art painting?] http://mathematica.stackexchange.com/questions/59132/how-to-ask-mathematica-to-imitate-andy-warhols-pop-art-painting
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
- asked by Putterboy (43 votes), answered by belisarius (50 votes)
================================== Can you answer these? ==================================
[How to add AccuracyGoal and PrecisionGoal options in a numerical function?] http://mathematica.stackexchange.com/questions/88182/how-to-add-accuracygoal-and-precisiongoal-options-in-a-numerical-function
There are many built-in functions that contain AccuracyGoal, PrecisionGoal and WorkingPrecision.
For instance
NSolve NSolve[x^3 + 2 x + 7 == 0, x, WorkingPrecision -> 40] {{x -> ...
- asked by Shutao Tang (4 votes)
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[What is the best way to take the Bourdet derivative?]http://mathematica.stackexchange.com/questions/87760/what-is-the-best-way-to-take-the-bourdet-derivative
Given a list of paired delta-time, delta-pressure, \((dt,dp)\), what might be the best approach to calculate the Bourdet derivative, described below? I am unclear how to manipulate elements of the ...
- asked by John (4 votes)
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[Dirichlet coefficients as limits: wrong] http://mathematica.stackexchange.com/questions/87766/dirichlet-coefficients-as-limits-wrong
Perhaps I should have included the word "bug" in my question. Here we go
There is a bug in this Limit
Limit[3^s (-1 - 2^-s + Zeta[s]), s -> \[Infinity]] (* 0 *) It should be 1 and there is a ... - asked by Dr. Wolfgang Hintze (7 votes)
================================== Top new questions this week: ==================================
[Faster binary Hamming weight for big integers?]http://mathematica.stackexchange.com/questions/87486/faster-binary-hamming-weight-for-big-integers
While working on an answer to Count the sequences in an array I found that DigitCount was the bottleneck in my code when used as DigitCount[num, 2, 1]. DigitCount first expands the number to an ...
- asked by Mr.Wizard (17 votes), answered by Oleksandr R. (15 votes)
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[Dataset vs an association of associations]http://mathematica.stackexchange.com/questions/87360/dataset-vs-an-association-of-associations
Associations with a record structure (e.g., a flat table) can be organised in one of two main ways. First as a list of associations, which is also used in the case of Mathematica’s data set ...
- asked by Mac (16 votes), answered by WReach (16 votes)
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[Count the sequences in an array]http://mathematica.stackexchange.com/questions/87406/count-the-sequences-in-an-array
Is there a short and easier way to count number of sequences in a list?
Let’s say I have three lists:
list1 = 0,0,0,0,0,0,0,1,1,1,1,1,0,0,0,0,0,0,0
list2 = 0,0,1,1,1,0,0,0,0,0,0,0,0,0,1,1,1,1,1 ...
- asked by gurluk (13 votes), answered by Leonid Shifrin (16 votes)
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[Plot is discontinuous (it shouldn’t be)]http://mathematica.stackexchange.com/questions/87504/plot-is-discontinuous-it-shouldnt-be
Plot[{(E^x)^(-2I \[Pi])Hypergeometric2F1[-2I \[Pi]-2I Sqrt[2]\[Pi], -2I \[Pi]+2I Sqrt[2]\[Pi],1-4I \[Pi],-E^x]+(E^x)^(2I \[Pi])Hypergeometric2F1[2I \[Pi]-2I...
- asked by grdgfgr (12 votes), answered by MarcoB (13 votes)
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[What’s wrong with Simplify and FullSimplify?]http://mathematica.stackexchange.com/questions/87305/whats-wrong-with-simplify-and-fullsimplify
I have a quite complex list of equations and inequalities I combine to a boundary condition for my cost function. After investigation of two days I found the bug (I really name it a bug!). One of my ...
- asked by akm (11 votes), answered by Bob Hanlon (3 votes)
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[What function generates random numbers in a compiled function?]http://mathematica.stackexchange.com/questions/87364/what-function-generates-random-numbers-in-a-compiled-function
I am writing a simulation for 2D random walk. I wrote several version of code, and found that the speed is like this (fastest to slowest): C++, Mathematica compiled procedural code, Mathematica ...
- asked by Felix (11 votes), answered by Szabolcs (11 votes)
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[Trainable WEKA segmentation of images] http://mathematica.stackexchange.com/questions/87256/trainable-weka-segmentation-of-images
Is there a Mathematica equivalent of Trainable WEKA Segmentation as implemented in Fiji, the image processing software? A Google search did not return any relevant links.
I attach the original image ...
- asked by JMarc (11 votes), answered by blochwave (17 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make Jacobian automatically in Mathematica] http://mathematica.stackexchange.com/questions/5790/how-to-make-jacobian-automatically-in-mathematica
If we have two vectors, a and b, how can I make Jacobian matrix automatically in Mathematica?
$$ a=\left( \begin{array}{c} \text{x1}^3+2\text{x2}^2 \\ 3\text{x1}^4+7\text{x2} \end{array} $$
- asked by George Mills (19 votes), answered by Jens (26 votes)
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[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (18 votes), answered by Artes (14 votes)
================================== Can you answer these? ==================================
[Does Sum calculate all terms before summing them?] http://mathematica.stackexchange.com/questions/87444/does-sum-calculate-all-terms-before-summing-them
After calculating the sum of a large number of large objects, using
B = Sum[RandomInteger[{0, 1}, {10^6}], {100}];
I find that MaxMemoryUsed[] has increased by 400MB, which is about 100 times ...
- asked by Stephen Powell (1 vote)
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[Performing a convolution for smoothing a function]http://mathematica.stackexchange.com/questions/87674/performing-a-convolution-for-smoothing-a-function
I want to smooth a one-dimensional oscillating function by convolving it with another function that I’ll call the screening function. This screening function should have a trapezoidal form and go to ...
- asked by user34801 (2 votes)
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[Alternative to use a function as an argument in Compile]http://mathematica.stackexchange.com/questions/87618/alternative-to-use-a-function-as-an-argument-in-compile
I am currently working on problems that require the use of functions such as :
Alpine[x__] := Total@Table[Abs[i*Sin[i] + 0.1*i], {i, x}]; ParabolaMin [x__] := Total@Table[i^2, {i, x}]; It may be ... - asked by Doedalos (1 vote)
================================== Top new questions this week: ==================================
[Does Mathematica have a built-in tool that allows one to operate on both sides of an equation?]http://mathematica.stackexchange.com/questions/86906/does-mathematica-have-a-built-in-tool-that-allows-one-to-operate-on-both-sides-o
Geogebra has a very neat CAS view that allows one to solve an equation step by step in the following fashion:
\(\quad \quad \quad \quad \quad \quad \quad \quad \quad \)
You type an equation and ...
- asked by Voyska (19 votes), answered by Alexei Boulbitch (25 votes)
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[Is ColorDistance symmetric?]http://mathematica.stackexchange.com/questions/86730/is-colordistance-symmetric
Is the function ColorDistance symmetric, i.e. is it always true that ColorDistance[a,b] == ColorDistance[b,a], as use of the word distance would suggest?
- asked by Szabolcs (15 votes), answered by Szabolcs (15 votes)
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[my Mathematica has turned orange and not able to find out why]http://mathematica.stackexchange.com/questions/87072/my-mathematica-has-turned-orange-and-not-able-to-find-out-why
I do not know what happened. But when I rebooted my PC, now Mathematica comes up orange colored. I shut down the PC and tried again, it is still orange. Here is screen shot:
I also did a reset. ...
- asked by Nasser (14 votes), answered by Sjoerd C. de Vries (14 votes)
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[Solve a trig equation system] http://mathematica.stackexchange.com/questions/86894/solve-a-trig-equation-system
Background of the problem
In the same plane, P is a fixed point, A,B,C are moving point, PA=a, PB=b, PC=c, find the maximize perimeter of ?ABC.
let ?BPC=A, ?CPA=B, ?APB=2*Pi-A-B, then the ...
- asked by mathe (13 votes), answered by Guess who it is. (19 votes)
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[How to retrieve current FaceForm?] http://mathematica.stackexchange.com/questions/86990/how-to-retrieve-current-faceform
The current colour in a Graphics object can be retrieved using CurrentValue["Color"] for use in Dynamic stuff.
Example:
Graphics[ RGBColor[2/3, 1/3, 2/3], Dynamic[If[CurrentValue["MouseOver"], ...
- asked by Szabolcs (12 votes), answered by Mr.Wizard (10 votes)
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[Using Simplify on a consistent system returns False]http://mathematica.stackexchange.com/questions/86791/using-simplify-on-a-consistent-system-returns-false
Bug introduced in 8.0 and persisting through 10.1.0 or later
It’s late, but am I missing something here? Why should two independent equations, which together are consistent, Simplify to False?
...
- asked by Michael E2 (10 votes), answered by Jens (5 votes)
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[Modifying strings in a list efficiently] http://mathematica.stackexchange.com/questions/86778/modifying-strings-in-a-list-efficiently
I have a list of strings \(\{s_1,s_2,\ldots ,s_n\}\). I would like to to produce the following list of strings:
$$ \{s_1<>1,\ 1<>s_2<>1,\ldots,\ 1<>s_n\} $$
In other words, I want ...
- asked by pre-kidney (10 votes), answered by ciao (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Finding real roots of negative numbers (for example, \(\sqrt [3]{-8}\))] http://mathematica.stackexchange.com/questions/3886/finding-real-roots-of-negative-numbers-for-example-sqrt3-8
Say I want to quickly calculate \(\sqrt [3]{-8}\), to which the most obvious solution is \(-2\).
When I input \(\sqrt [3]{-8}\) or Power[-8, 3^-1]
, Mathematica gives the result \(2 (-1)^{1/3}\). Not what I
...
- asked by jtbandes (36 votes), answered by Brett Champion (19 votes)
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[Parallel and perpendicular symbol from Mathematica to LaTeX] http://mathematica.stackexchange.com/questions/46538/parallel-and-perpendicular-symbol-from-mathematica-to-latex
I want to get the following expression from Mathematica to LaTeX:
\begin{bmatrix} E_{\parallel} \\ E_{\perp} \end{bmatrix}
I have tried to use inbuilt ’symbol’ character from the special ...
- asked by Steve Hatcher (4 votes), answered by Sjoerd C. de Vries (9 votes)
================================== Can you answer these? ==================================
[Why is the Max function so slow when operating on lists of dates?]http://mathematica.stackexchange.com/questions/87204/why-is-the-max-function-so-slow-when-operating-on-lists-of-dates
Example:
dates = DateRange[DateObject[], DatePlus[DateObject[], 15]]; First[AbsoluteTiming[Max[dates]]]
(* 21.364247 *)
As a workaround, DateObject[Max[AbsoluteTime /@ dates]] will get the same ...
- asked by rhennigan (3 votes)
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[Discrete Fourier Transform baseline subtraction]http://mathematica.stackexchange.com/questions/86951/discrete-fourier-transform-baseline-subtraction
I am trying to remove sinusoidal variability from a set of evenly-spaced intensity vs. time data. These data contain periodic events that are separated by a normalized (but sinusoidally variable) ...
- asked by John (1 vote)
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[How to use Wolfram language in an external program with low latency?]http://mathematica.stackexchange.com/questions/87168/how-to-use-wolfram-language-in-an-external-program-with-low-latency
Im using Wolfram language on Pi B,and I want to compile a ’.m’ file (like "test.m" that contains Wolfram functions), in an external program like a C/C++ and then Export the output in an image file ...
- asked by Babak akbari (1 vote)
================================== Top new questions this week: ==================================
[Summer Solstice Spurious Correlations Challenge] http://mathematica.stackexchange.com/questions/86413/summer-solstice-spurious-correlations-challenge
I came across this hilarious web site that has charts of bizarre "correlations" between disparate categories. Results like this:
In the spirit of my summer solstice shedding spuriously earned rep. ...
- asked by ciao (20 votes)
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[Is there any Mathematica functionality enabling its use for the blind?]http://mathematica.stackexchange.com/questions/86538/is-there-any-mathematica-functionality-enabling-its-use-for-the-blind
A colleague of mine has become blind as the result of a sudden medical misfortune. We want to help him to feel useful and active again. We, however, still cannot determine what can be done and to what ...
- asked by Alexei Boulbitch (17 votes)
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[Nearest neighbor search in n-dimensions]http://mathematica.stackexchange.com/questions/86262/nearest-neighbor-search-in-n-dimensions
Suppose a list of items such as: L1 = RandomReal[0, 100, 1000];
I need to find the position of each k-neighbor in the original list. And very quickly if possible. As we can see, the problem is ...
- asked by Doedalos (14 votes), answered by bill s (14 votes)
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[HDF5 importing large arrays]http://mathematica.stackexchange.com/questions/86544/hdf5-importing-large-arrays
I have some computations that output a 300,000,000 element array of long unsigned ints, so about 2.4GB, in an h5 file. Mathematica handles files south of 2GB fine, albeit taking very long to import ...
- asked by Kartoffelpelz (13 votes), answered by Albert Retey (7 votes)
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[How does Rescale[] handle infinities?]http://mathematica.stackexchange.com/questions/86365/how-does-rescale-handle-infinities
Rescale appears to be a simple function. It just does a simple linear \(y = a x + b\) type rescaling of the values:
Rescale@Range[0, 10] (* 0, 1/10, 1/5, 3/10, 2/5, 1/2, 3/5, 7/10, 4/5, 9/10, 1 *)
...
- asked by Szabolcs (13 votes), answered by LLlAMnYP (5 votes)
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[How to fill the space outside of an image after rotating it]http://mathematica.stackexchange.com/questions/86528/how-to-fill-the-space-outside-of-an-image-after-rotating-it
I want to rotate this image by -50 degrees, and then fill up the black space around the rotated image with a bluish color. I can’t find any documentation/answers that suggest how to do it. (Sorry ...
- asked by George Wolfe (12 votes), answered by ubpdqn (21 votes)
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[How do I add my own help pages to the in-built Wolfram documentation?]http://mathematica.stackexchange.com/questions/86137/how-do-i-add-my-own-help-pages-to-the-in-built-wolfram-documentation
How do I add my own help pages to the in-built Wolfram documentation ?
- asked by Peter Lindsay (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?]http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by Guess who it is. (352 votes), answered by faysou (323 votes)
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[How to express trigonometric equation in terms of of given trigonometric function?]http://mathematica.stackexchange.com/questions/434/how-to-express-trigonometric-equation-in-terms-of-of-given-trigonometric-functio
How can I express a trigonometric equation / identity in terms of a given trigonometric function?
using following trigonometric identities
Sin[x]^2+Cos[x]^2==1 Sin[x]/Cos[x]==Tan[x] ...
- asked by Prashant Bhate (17 votes), answered by Simon (24 votes)
================================== Can you answer these? ==================================
[Export 3D plot or Graphics3D object as stereoscopic 3D .jps file]http://mathematica.stackexchange.com/questions/86354/export-3d-plot-or-graphics3d-object-as-stereoscopic-3d-jps-file
I recently came across some Matlab code to output a 3D graph as a stereoscopic left/right .JPS file, viewable e.g. with 3D Media Viewer, Stereoscopic Player or using any 3D television or beamer: ...
- asked by Tom Wenseleers (2 votes)
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[DiscretizeRegion of ImplicitRegion too small]http://mathematica.stackexchange.com/questions/86600/discretizeregion-of-implicitregion-too-small
I have a 2D function that has some sharp peeks within the my domain. I need to find a tight region that contains these sharp peeks. The following is an example of what I would like to do.
An example ...
- asked by c186282 (2 votes)
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[Is it possible to automatically apply Parallelize when possible]http://mathematica.stackexchange.com/questions/86373/is-it-possible-to-automatically-apply-parallelize-when-possible
Parallelize in Mathematica is pretty easy to use. Most of the time, applying Parallelize to an expression, it tries to evaluates expr using automatic parallelization. Is there an option that ...
- asked by Kattern (2 votes)
================================== Top new questions this week: ==================================
[Memoization with pure functions?]http://mathematica.stackexchange.com/questions/85750/memoization-with-pure-functions
Is this possible?
If I have a simple function, say:
f=If[#>0,1,2]& then for each value of # this will re-evaluate f right?
Is it possible to define a pure function like this:
...
- asked by maria (30 votes), answered by Leonid Shifrin (39 votes)
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[Trying to Visualize a Collatz - The Collatz conjecture] http://mathematica.stackexchange.com/questions/85718/trying-to-visualize-a-collatz-the-collatz-conjecture
So I’m new in this and learning— and I happen to have this collatz
collatz[x_, y_] := If[x == 3*y || x == 2*y + 1 || y == 3*x || y == 2*x + 2, 2, 0] Array[#1 + 2 #2 &, {4, 4}]
output =
3, ...
- asked by Madona (20 votes), answered by Sjoerd C. de Vries (25 votes)
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[How to plot an emission spectrum?]http://mathematica.stackexchange.com/questions/85990/how-to-plot-an-emission-spectrum
If I have a list of data with various wavelengths in nanometers, how would I plot them on a graph so it looks like this:
So far I have managed to plot a spectrum in DensityPlot, but I have no idea ...
- asked by Alizter (15 votes), answered by MarcoB (18 votes)
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[How: 2D scatterplots with quantitative density-dependent coloring]http://mathematica.stackexchange.com/questions/85530/how-2d-scatterplots-with-quantitative-density-dependent-coloring
Consider the following scatterplot of a 50K-point dataset:
ListPlot[data, AspectRatio -> Automatic, PlotRange -> {{x0, x1}, {y0, y1}}, ImageSize -> Small, Frame -> True, ...
- asked by kjo (15 votes), answered by MarcoB (16 votes)
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[How to define a recursive pattern?]http://mathematica.stackexchange.com/questions/85683/how-to-define-a-recursive-pattern
I want to translate this recursive syntactic definition into a Mathematica pattern1:
\[ \mathtt {x}: \begin {cases} \text {Null}\\ \{\textit {integer}, \mathtt {x}\} \end {cases} \]
In other ...
- asked by kjo (12 votes), answered by Leonid Shifrin (17 votes)
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[Mathematica: 3D plot based on combined 2D graphs] http://mathematica.stackexchange.com/questions/85717/mathematica-3d-plot-based-on-combined-2d-graphs
I have several sigmoidal fits to 3 different datasets, with mean fit predictions plus the 95% confidence limits (not symmetrical around the mean) and the actual data.
I would now like to show these ...
- asked by Tom Wenseleers (11 votes), answered by halmir (13 votes)
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[What’s the function that takes X[Y[z___]] to Y[X[z___]]?
("swap heads")]
http://mathematica.stackexchange.com/questions/85872/whats-the-function-that-takes-xyz-to-yxz-swap-heads
I’ve seen the operation described in the title before (basically, swap the heads of the first two levels of an expression), but I can’t find it...
Does anyone know the function (or idiom/incantation) ...
- asked by kjo (11 votes), answered by Kuba (13 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?]http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by Guess who it is. (351 votes), answered by faysou (323 votes)
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[Is it possible to export the equations from Mathematica to MATLAB?]http://mathematica.stackexchange.com/questions/14035/is-it-possible-to-export-the-equations-from-mathematica-to-matlab
Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?
- asked by Seyhmus Gungoren (23 votes), answered by The Toad (30 votes)
================================== Can you answer these? ==================================
[Sub-processes (like XML.exe, GZIP.exe) not ended properly]http://mathematica.stackexchange.com/questions/85668/sub-processes-like-xml-exe-gzip-exe-not-ended-properly
I have difficulties with running MathKernel.exe from .NET and sub-processes like XML.exe and GZIP.exe, which are not terminated properly. Sometimes even the MathKernel.exe task stays active and is ...
- asked by akm (1 vote)
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[Fitting data to a complicated function]http://mathematica.stackexchange.com/questions/85778/fitting-data-to-a-complicated-function
So, where to begin. I have a certain dataset that I want to fit to a function. However, the function is rather complicated (matrix inversions, linearsolve) and does in general not have a closed form ...
- asked by user129412 (2 votes)
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[Partitioning Table]http://mathematica.stackexchange.com/questions/85820/partitioning-table
I have a long vector array in the following format:
x1,y1,z1,a,b,c,x1,y1,z2,d,e,f,...,x1,y2,z1,g,h,i,x1,y2,z2, ...
- asked by user27670 (3 votes)
================================== Top new questions this week: ==================================
[Error "Throw::nocatch: Uncaught Throw[False] returned to top level" given each time I open a new Mathematica 10.1 session]http://mathematica.stackexchange.com/questions/85013/error-thrownocatch-uncaught-throwfalse-returned-to-top-level-given-each-t
From a few days now each time I open a new Mathematica session I get the small error messages window with the error
Throw::nocatch: Uncaught Throw[False] returned to top level.
repeatedly given, as ...
- asked by glance (13 votes), answered by ilian (7 votes)
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[Is it possible to extract data from an eps plot not generated in Mathematica?]http://mathematica.stackexchange.com/questions/85320/is-it-possible-to-extract-data-from-an-eps-plot-not-generated-in-mathematica
I want to extract data from an eps plot not generated in Mathematica and replot it. In general is it possible to extract data from plots in any formats in Mathematica? I searched but unfortunately ...
- asked by Soodeh Z. (11 votes), answered by Alexey Popkov (15 votes)
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[Mimic a procedural, recursive clustering algorithm for site percolation using functional programming]http://mathematica.stackexchange.com/questions/85185/mimic-a-procedural-recursive-clustering-algorithm-for-site-percolation-using-fu
Sorry in advance for my logorrhea: I just want to make sure all of the information is here.
Context and Question
I am investigating site percolation on a square lattice. I have a working, ...
- asked by march (11 votes), answered by Virgil (7 votes)
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[Subtracting two plots from each other after shifting one]http://mathematica.stackexchange.com/questions/85420/subtracting-two-plots-from-each-other-after-shifting-one
I have the following lists representing energy spectra that need to be subtracted from each other to produce a difference spectrum.
data1 = ...
- asked by W. Heisenberg (10 votes), answered by Histograms (15 votes)
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[Lookup with default broken in Dataset]http://mathematica.stackexchange.com/questions/85114/lookup-with-default-broken-in-dataset
Given an Association,
data = <|"1" -> <|"A" -> 10, "B" -> 20|>, "2" -> <|"C" -> 30, "B" -> 40|>|>
Lookup works w/ default:
data // Map[Lookup[#, "A", 0] ...
- asked by alancalvitti (10 votes), answered by WReach (5 votes)
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[Confused by the opts : OptionsPattern[ ] pattern] http://mathematica.stackexchange.com/questions/85347/confused-by-the-opts-optionspattern-pattern
I’m trying to make sense of the syntax in the clause opts:OptionsPattern[], as found in this standard "rule-based" (pseudo-)function definition pattern:
aFunction[a1_, a2_, a3_, ...
- asked by kjo (9 votes)
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[Why Mathematica cannot apply The Fundamental Theorem of Calculus automatically?] http://mathematica.stackexchange.com/questions/85166/why-mathematica-cannot-apply-the-fundamental-theorem-of-calculus-automatically
For some reason Mathematica cannot evaluate this definite integral:
$Version (* 10.1.0 for Microsoft Windows (64-bit) (March 24, 2015) *) Integrate[1/(Sqrt[x] Sqrt[1 - x + x^2]), {x, 1, 2}] (* ...
- asked by Vladimir Reshetnikov (8 votes), answered by Dr. Wolfgang Hintze (4 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make an inkblot?] http://mathematica.stackexchange.com/questions/3345/how-to-make-an-inkblot
How to effectively create a polygon that looks like a realistic inkblot? So far, I could come up with this (borrowing from Ed Pegg Jr.’s Rorschach demonstration):
RandomBlot[num_, opts___] := ...
- asked by Istvan Zachar (71 votes), answered by Sjoerd C. de Vries (38 votes)
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[1 Plot, 2 Scale/Axis] http://mathematica.stackexchange.com/questions/627/1-plot-2-scale-axis
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
- asked by 500 (84 votes), answered by ArgentoSapiens (77 votes)
================================== Can you answer these? ==================================
[ConvexHullMesh sometimes excludes valid points from convex hull] http://mathematica.stackexchange.com/questions/85466/convexhullmesh-sometimes-excludes-valid-points-from-convex-hull
I have a sequence of polytopes that I am trying to visualize, and I find that ConvexHullMesh sometimes excludes points from the convex hull, and it does so inconsistently.
In particular, notice these ...
- asked by Marcus P S (2 votes)
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[How to specify finite difference approximation order in ‘NDSolve‘] http://mathematica.stackexchange.com/questions/85439/how-to-specify-finite-difference-approximation-order-in-ndsolve
According to here, NDSolve, when using the method of lines, creates partial derivatives in the spacial coordinate (lets talk just about one spacial coordinate for now) using the finite difference ...
- asked by rspencer (1 vote)
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[Better to have infinities in limits or integrands (‘NIntegrate‘)?] http://mathematica.stackexchange.com/questions/85483/better-to-have-infinities-in-limits-or-integrands-nintegrate
I'm using ListPlot to plot the integral of a function with respect of the function's second variable: ListPlot[NIntegrate[integrand[x, #], {x, -Infinity, 0}]&/@Range[10, 20]]. The integral ...
- asked by Love Learning (2 votes)
================================== Top new questions this week: ==================================
[Python-style plots in Mathematica] http://mathematica.stackexchange.com/questions/84877/python-style-plots-in-mathematica
I love making plots in Mathematica. And i love to spend a lot of time making high-quality plots that maximize readability and aesthetics. For most cases, mathematica can make very beautiful images, ...
- asked by Pablo Galindo Salgado (28 votes), answered by halirutan (29 votes)
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[Numerically solving Helmholtz equation in 3D for arbitrary shapes] http://mathematica.stackexchange.com/questions/84726/numerically-solving-helmholtz-equation-in-3d-for-arbitrary-shapes
Context
While studying manifold Learning I got interested in finding the eigenvectors of the Laplacian. (also in connection to this problem of solving the heat equation)
Following this and that ...
- asked by chris (22 votes)
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[Can A Plot Be Overlayed With A Map?] http://mathematica.stackexchange.com/questions/84598/can-a-plot-be-overlayed-with-a-map
Some brief, only slightly important background. I am doing a research project using the data from NASA’s GRACE mission. I wrote a short Perl script to take two data files and find the change in ...
- asked by disc otter (16 votes), answered by Mr.Wizard (16 votes)
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[How can we make publication-quality PlotMarkers without version 10?] http://mathematica.stackexchange.com/questions/84857/how-can-we-make-publication-quality-plotmarkers-without-version-10
Suppose that for certain reasons we are not yet using Mathematica version 10, or we have a version with buggy PlotMarkers. It is well known that the default markers are font glyphs, and as a result ...
- asked by Oleksandr R. (15 votes), answered by Oleksandr R. (13 votes)
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[Eigenfunctions of the Laplacian on an arbitrary mesh] http://mathematica.stackexchange.com/questions/84607/eigenfunctions-of-the-laplacian-on-an-arbitrary-mesh
So, I’ve constructed a mesh over which I’d like to find eigenfunctions of Laplace’s equation with a free boundary (a zero Neumann boundary condition along the edge).
Mostly because I figured an ...
- asked by Michael Lee (14 votes), answered by Michael Lee (4 votes)
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[Why is ListPlot so slow here?] http://mathematica.stackexchange.com/questions/84739/why-is-listplot-so-slow-here
While examining How can I monitor the progress of a Plot? I was surprised to discover that in some cases ListPlot in version 10.0 and 10.1 is orders of magnitude slower than it is in version 7. This ...
- asked by Mr.Wizard (13 votes)
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[Is there a way to control which special forms Normal converts?] http://mathematica.stackexchange.com/questions/84783/is-there-a-way-to-control-which-special-forms-normal-converts
Normal documentation reads:
Normal[expr] converts expr to a normal expression, from a variety of special forms.
But is there a way to control which special forms it converts and which it does ...
- asked by Mr.Wizard (11 votes), answered by Mr.Wizard (13 votes)
================================== Greatest hits from previous weeks: ==================================
[Get a "step-by-step" evaluation in Mathematica] http://mathematica.stackexchange.com/questions/148/get-a-step-by-step-evaluation-in-mathematica
Is it possible in Mathematica to get a step-by-step evaluation of some functions; that’s to say, outputting not only the result but all the stages that have led to it? If so, how does one do it?
...
- asked by Skydreamer (70 votes), answered by Guess who it is. (57 votes)
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[Plotting Complex Quantity Functions] http://mathematica.stackexchange.com/questions/3458/plotting-complex-quantity-functions
Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ...
- asked by night owl (17 votes), answered by Artes (19 votes)
================================== Can you answer these? ==================================
[Why is setting SynchronousUpdating -> True causes mouse motion to pause/freeze Dynamics?] http://mathematica.stackexchange.com/questions/84826/why-is-setting-synchronousupdating-true-causes-mouse-motion-to-pause-freeze-d
When making a Manipulate, I noticed that setting SynchronousUpdating -> True have a very annoying side effect. By just moving the mouse anywhere on the same cell the Manipulate is running, causes ...
- asked by Nasser (4 votes)
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[Using a Mathematica index as a DiscreteVariable in NDSolve when solving a coupled set of ordinary differential equations] http://mathematica.stackexchange.com/questions/84471/using-a-mathematica-index-as-a-discretevariable-in-ndsolve-when-solving-a-couple
Context
Since the explanation below of the problem to be solved is lengthy, let me preamble this by saying that I have code that works to solve the problem, but I don’t know whether (1) it’s ...
- asked by march (6 votes)
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[Why is Transpose Dataset slow in one direction]http://mathematica.stackexchange.com/questions/84585/why-is-transpose-dataset-slow-in-one-direction
Transpose is faster when it distributes Keys at the 2nd level of a Dataset than when it factors them out.
ds[len_] := <|"a" -> Range[len], "b" -> (1/Range[len] // N)|> // Dataset
...
- asked by alancalvitti (4 votes)
================================== Top new questions this week: ==================================
[A bug in Integrate] http://mathematica.stackexchange.com/questions/84089/a-bug-in-integrate
Integrate[(1 + 16 Tan[2 x - y]^2)/(1 + 4 Tan[2 x - y]^2), {x, 0, 2 Pi}]
Mathematica (wrong) output is (tested under versions 8 and 10.0, took 1 minute of CPU time)
10 Pi
The correct value of this ...
- asked by Vaclav Kotesovec (17 votes), answered by Histograms (11 votes)
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[What is the FrontEnd?] http://mathematica.stackexchange.com/questions/84173/what-is-the-frontend
Can anyone sort out what the Front-End is, how it is structured and what its relationship to the Kernel is. The FrontEnd is mentioned quite often but elusively avoids to be caught and clearly defined. ...
- asked by MathLind (15 votes), answered by Mr.Wizard (12 votes)
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[Regime Change Stochastic Process] http://mathematica.stackexchange.com/questions/84054/regime-change-stochastic-process
I would like to simulate an Ito process in which the drift and diffusion terms change after hitting a boundary for the first time.
For example, a Geometric Brownian Motion X which has 0 drift and ...
- asked by Shffl (12 votes), answered by Sjoerd C. de Vries (9 votes)
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[How to speed up Colorize] http://mathematica.stackexchange.com/questions/83967/how-to-speed-up-colorize
I have a list of about 500 images similar to the following:
A = Import["http://i.stack.imgur.com/1bV4O.png"] AbsoluteTiming[Colorize[A, ColorFunction -> "AvocadoColors"]]
Gives 0.6 ...
- asked by DarrenM (11 votes), answered by bill s (7 votes)
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[Does Mathematica have an equivalent of Python’s float.as_integer_ratio
?]
http://mathematica.stackexchange.com/questions/84234/does-mathematica-have-an-equivalent-of-pythons-float-as-integer-ratio
The Python programming language has a float.as_integer_ratio(x) function which exactly converts an IEEE 754 floating-point number into a numerator/denominator pair of integers. For example:
...
- asked by David Zhang (10 votes), answered by Guess who it is. (15 votes)
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[Does Mathematica have an equivalent of C’s nextafter?]http://mathematica.stackexchange.com/questions/84237/does-mathematica-have-an-equivalent-of-cs-nextafter
In C (and many other programming languages), there is a function
double nextafter(double x, double y)
which takes two (IEEE 754) floating-point numbers and returns the next representable ...
- asked by David Zhang (9 votes), answered by Michael E2 (5 votes)
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[How can I make FilledCurve smoother?]http://mathematica.stackexchange.com/questions/84247/how-can-i-make-filledcurve-smoother
In How can I generate and randomly assign color to annular sectors? J.M. showed an interesting way to create a sector graphic using FilledCurve. Unfortunately it was marred by an inferior rendering ...
- asked by Mr.Wizard (9 votes), answered by Mr.Wizard (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Alternatives to Mathematica]http://mathematica.stackexchange.com/questions/28162/alternatives-to-mathematica
Inspired by the recent question Alternatives to LaTeX (currently 58 upvotes) on http://tex.stackexchange.com/:
Are there any paid-for or open source alternatives to Mathematica which produce equal or ...
- asked by akk (28 votes), answered by Sumit (17 votes)
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[How do I draw a pair of buttocks?]http://mathematica.stackexchange.com/questions/66538/how-do-i-draw-a-pair-of-buttocks
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
- asked by Simpleton Jack (221 votes), answered by mikuszefski (340 votes)
================================== Can you answer these? ==================================
[Simplification with absolute value]http://mathematica.stackexchange.com/questions/83933/simplification-with-absolute-value
I have a long expression that has absolute values in the exponent. Some parts of the expression would clearly simplify if one assumes that the power is an odd or even integer. When I give one of this ...
- asked by Jools (1 vote)
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[Wrong Limit with LaguerreL] http://mathematica.stackexchange.com/questions/84077/wrong-limit-with-laguerrel
Limit[(n!LaguerreL[n,-1]/(n^(n+1/4)/Sqrt[2]/E^(n-2Sqrt[n]+1/2))-1)Sqrt[n],n->\[Infinity]]
Mathematica (wrong) output
13/16 = 0.8125
The right result is:
31/48 = 0.645833...
But numerically it ...
- asked by Vaclav Kotesovec (5 votes)
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[Fast construction and reshaping of large tensors]http://mathematica.stackexchange.com/questions/83999/fast-construction-and-reshaping-of-large-tensors
I’m trying to construct a large matrix which is derived from some higher rank tensor (the rank of interest to me changes case by case, so it needs to be a general method). Currently, the process of ...
- asked by user12876 (1 vote)
================================== Top new questions this week: ==================================
[Why is calling Dot with many arguments so inefficient?] http://mathematica.stackexchange.com/questions/83412/why-is-calling-dot-with-many-arguments-so-inefficient
Say I want to multiply a reasonably large list of symbolic matrices.
tab = Partition[#,4]&/@ Table[ Symbol[CharacterRange["a","z"][[nm]]<>ToString[nn]],{nn,1,12},{nm,1,16}];
...
- asked by murphy (13 votes), answered by Hurkyl (7 votes)
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[Performance problems in new Sequence functions]http://mathematica.stackexchange.com/questions/83325/performance-problems-in-new-sequence-functions
The new-in-10.1 Sequence* family of functions should provide newly optimized methods for handling sequence problems. Happily in some cases they do! For example Murta reports 28 times faster ...
- asked by Mr.Wizard (12 votes)
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[What are SparseArray Properties? How and when should they be used?]http://mathematica.stackexchange.com/questions/83721/what-are-sparsearray-properties-how-and-when-should-they-be-used
A strange undocumented form of SparseArray is increasingly used in answers on this site:
SparseArray[(* data *)]["NonzeroPositions"]
What is this, and why would anyone want to use this? Are there ...
- asked by Mr.Wizard (11 votes), answered by Mr.Wizard (12 votes)
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[A better (but slower) FullSimplify function]http://mathematica.stackexchange.com/questions/83756/a-better-but-slower-fullsimplify-function
I am creating this question and posting an answer to it as a help for those who have problems with Mathematica simplification oddities that appear in many other questions on the site.
First of all, ...
- asked by Giovanni (10 votes), answered by Giovanni (10 votes)
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[Is there a programmatic equivalent of Edit > Find?]http://mathematica.stackexchange.com/questions/83492/is-there-a-programmatic-equivalent-of-edit-find
Most things that can be done via the front-end interface in Mathematica can also be accomplished by some function. Is that the case for find-and-replacing? That is, is there some code I could execute ...
- asked by thecommexokid (10 votes), answered by Mr.Wizard (10 votes)
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[Is FullGraphics an abandoned function? Is there an alternative?]http://mathematica.stackexchange.com/questions/83648/is-fullgraphics-an-abandoned-function-is-there-an-alternative
FullGraphics hasn’t worked entirely for a long time and the situation appears to be getting worse instead of better. In Mathematica 10.0 and 10.1 a simple usage throws numerous errors and returns a ...
- asked by Mr.Wizard (10 votes)
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[How to find all the positions of max value of a list efficiently?]http://mathematica.stackexchange.com/questions/83602/how-to-find-all-the-positions-of-max-value-of-a-list-efficiently
For Example, list=RandomInteger[1,100,2000]. Yes,I know Position[list,Max[list]] can do. But it’s based on pattern matching! Ordering[list,-1] could find one position but not all. So how to ...
- asked by WateSoyan (10 votes), answered by Pickett (14 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make use of Associations?]http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (74 votes), answered by Leonid Shifrin (80 votes)
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[How to find the position of elements in a list satisfying criteria] http://mathematica.stackexchange.com/questions/180/how-to-find-the-position-of-elements-in-a-list-satisfying-criteria
Say I have a list x=2,4,6,8,10 and I want to find out the positions of the elements that are greater than 7.
Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
- asked by PeterR (24 votes), answered by Guess who it is. (19 votes)
================================== Can you answer these? ==================================
[Indeterminate expression 0(I*Infinity]) on indefinite integrals on first use only]http://mathematica.stackexchange.com/questions/83450/indeterminate-expression-0iinfinity-on-indefinite-integrals-on-first-use-onl
I do not know if this is new or not, I googled before.
Windows 7, 10.1 64 bit: Integrals generate this error message
The strange thing also is that the message shows up the first time the command ...
- asked by Nasser (3 votes)
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[Undo automatic update] http://mathematica.stackexchange.com/questions/83795/undo-automatic-update
I was working with Predict function (with a neural network and today, and when I executed the same notebook I have been working for some time, Machine Learning package was automatically updated (it ...
- asked by Miguel (2 votes)
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[How to match the arguments of the function in any order] http://mathematica.stackexchange.com/questions/83396/how-to-match-the-arguments-of-the-function-in-any-order
The issue is the following, with a dumb function with (4) arguments of (4) different heads (for each head is always no grater than one arguments):
func[x_a,y_b,z_c,w_d] := Print[x,y,z,w]
If I type ...
- asked by d555 (3 votes)
================================== Top new questions this week: ==================================
[Documentation of the frequently-used functions in the context of Internal‘ and Compile‘] http://mathematica.stackexchange.com/questions/82790/documentation-of-the-frequently-used-functions-in-the-context-of-internal-and-c
In this site, I have gradually found out that there is a collection of functions in all kinds of answers. For instance, Compile‘GetElement, Internal‘Bag,etc. However, these functions are undocumented. ...
- asked by Shutao Tang (21 votes), answered by blochwave (12 votes)
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[Does Mathematica store hidden information for matrix objects?]http://mathematica.stackexchange.com/questions/82854/does-mathematica-store-hidden-information-for-matrix-objects
Bug introduced in 10.0.0 and persisting through 10.1.0 or later
I found a case where calling one built-in function (HermitianMatrixQ) for a given matrix changes the behavior of another built-in ...
- asked by user3126814 (20 votes)
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[What’s going on with performance of Tally here?]http://mathematica.stackexchange.com/questions/82978/whats-going-on-with-performance-of-tally-here
Observe:
l1 = l2 = RandomInteger[1, 100000, 1000000]; l2[[-1]] = -1; t1 = First@Timing@Tally[l1]; t2 = First@Timing@Tally[l2];
l1 = l2 = RandomInteger[1, 100000, 1000100]; l2[[-1]] = -1; t3 = ...
- asked by ciao (16 votes), answered by Michael E2 (4 votes)
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[Hightlight all the self-intersections of a Lissajous figure]http://mathematica.stackexchange.com/questions/83118/hightlight-all-the-self-intersections-of-a-lissajous-figure
This graphalso known as a Lissajous figurecontains so many self-intersections.How can I highlight them?
ParametricPlot[{Sin[100 t], Sin[99 t]}, {t, 0, 2 Pi}, PlotRange -> All]
- asked by WateSoyan (13 votes), answered by 2012rcampion (22 votes)
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[Is MathieuC for moderately large imaginary arguments broken?] http://mathematica.stackexchange.com/questions/83032/is-mathieuc-for-moderately-large-imaginary-arguments-broken
I’m trying to plot MathieuC[-3,0.3,I x] for \(x\in [0,10]\), and here’s what I get (using ListPlot and Table instead of Plot to make computation faster and use a regular grid):
...
- asked by Ruslan (13 votes)
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[In 10.1.0 BenchmarkPlot doesn’t work?] http://mathematica.stackexchange.com/questions/83226/in-10-1-0-benchmarkplot-doesnt-work
In Mathematica 10.1.0 BenchmarkPlot from the GeneralUtilities package doesn’t work; copying Taliesin Beynon’s initial use of the function on this site:
Needs["GeneralUtilities`"] myPosIdx[x_] := ...
- asked by Mr.Wizard (12 votes), answered by Mr.Wizard (12 votes)
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[How to ContourPlot a function of the coordinates on the Earth’s surface on a map projection] http://mathematica.stackexchange.com/questions/83050/how-to-contourplot-a-function-of-the-coordinates-on-the-earths-surface-on-a-map
There are two similar questions (this and this), but one is too specific and the other is apparently not clear and has no answers. I’ll try to make the question more complete.
Suppose you have a ...
- asked by unlikely (12 votes), answered by Kuba (13 votes)
================================== Greatest hits from previous weeks: ==================================
[Is it possible to export the equations from Mathematica to MATLAB?] http://mathematica.stackexchange.com/questions/14035/is-it-possible-to-export-the-equations-from-mathematica-to-matlab
Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax?
- asked by Seyhmus Gungoren (23 votes), answered by The Toad (30 votes)
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[How do I draw a pair of buttocks?] http://mathematica.stackexchange.com/questions/66538/how-do-i-draw-a-pair-of-buttocks
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
- asked by Simpleton Jack (216 votes), answered by mikuszefski (337 votes)
================================== Can you answer these? ==================================
[Negative accuracy numerics ( 0“-128 notation )] http://mathematica.stackexchange.com/questions/82683/negative-accuracy-numerics-0-128-notation
What does it mean to have a negative accuracy number?
I understand 0“128 to mean "the number zero to 128 decimal points". Mathematica corroborates this:
In[1]:= 0``128 < 1 (* Out[1]= True *) ...
- asked by jjstankowicz (6 votes)
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[Orthogonal projection of NURBS surface]http://mathematica.stackexchange.com/questions/82855/orthogonal-projection-of-nurbs-surface
How can one make an orthogonal projection of NURBS surface? For example the one from wolfram demos http://demonstrations.wolfram.com/DesigningACarBodyWithSplines/.
- asked by justartem (2 votes)
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[DiracDelta and version 10.0.0] http://mathematica.stackexchange.com/questions/83198/diracdelta-and-version-10-0-0
Note: This issue seems to affect version 10.0.0 only and is fixed in 10.0.1, 10.0.2, and 10.1
When evaluating the following two inputs:
Integrate[DiracDelta[1-x] DiracDelta[y-2] Sin[x] Cos[y], x, ...
- asked by Nid (2 votes)
================================== Top new questions this week: ==================================
[Two, maybe related, issues with ParallelTable] http://mathematica.stackexchange.com/questions/82496/two-maybe-related-issues-with-paralleltable
I will use a very simple example for demonstrating two issues I face with ParallelTable, one with respect to the speed and one with respect to the use of memory. These issues might be related.
Let us ...
- asked by Fred Simons (14 votes), answered by Mr.Wizard (2 votes)
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[Switch from logarithmic to linear scaling partway along a plot’s axis] http://mathematica.stackexchange.com/questions/82581/switch-from-logarithmic-to-linear-scaling-partway-along-a-plots-axis
In the 2015 Planck satellite results, they give the latest plot of the temperature power spectrum of the cosmic microwave background, which I show below. (I am only interested in the main plot; you ...
- asked by thecommexokid (11 votes), answered by LLlAMnYP (13 votes)
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[Solving and Animating Three Body Problem] http://mathematica.stackexchange.com/questions/81340/solving-and-animating-three-body-problem
I am attempting to solve a three-body problem using the Lagrange formalism, with a 1/r potential.
I started off by defining T and U (kinetic and potential energy) as follows:
Tx = .5 m1 x1'[t]^2 + ...
- asked by Puru (11 votes), answered by Vitaliy Kaurov (22 votes)
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[Analyze touching particles with holes in a microscopic image] http://mathematica.stackexchange.com/questions/81176/analyze-touching-particles-with-holes-in-a-microscopic-image
I am looking for an easy method to count individual particles in a microscopic image. It is quite difficult for Mathematica to detect them, because they are touching each other. I am quite a beginner ...
- asked by Niki (11 votes), answered by nikie (15 votes)
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[How do I draw a polygon defined by a list of data points?] http://mathematica.stackexchange.com/questions/81191/how-do-i-draw-a-polygon-defined-by-a-list-of-data-points
I am attempting to make a 3D model of a device defined by a list of x,y,z points, digitized from a 2D image. The z coordinate is defined in mma.
What I tried so far:
area = 0, 452.45658, ...
- asked by Peter (10 votes), answered by kguler (7 votes)
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[Is there a good reason for the removal of this FrameTicks syntax?] http://mathematica.stackexchange.com/questions/82625/is-there-a-good-reason-for-the-removal-of-this-frameticks-syntax
In past versions of Mathematica one could use a terse syntax for FrameTicks:
bottom, left, top, right
In 10.1 this syntax is no longer recognized requiring the addition of two sets of brackets:
...
- asked by Mr.Wizard (8 votes)
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[How to remove outliers from data] http://mathematica.stackexchange.com/questions/81121/how-to-remove-outliers-from-data
I have a data with noise which some times includes significant outliers. The position of the outliers are random.
For example:
data1 = Table[PDF[NormalDistribution[3.5, .8], i], i, -5, 15, .01] + ...
- asked by Algohi (8 votes), answered by lalmei (8 votes)
================================== Greatest hits from previous weeks: ==================================
[1 Plot, 2 Scale/Axis] http://mathematica.stackexchange.com/questions/627/1-plot-2-scale-axis
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
- asked by 500 (81 votes), answered by ArgentoSapiens (75 votes)
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[How to find the position of elements in a list satisfying criteria] http://mathematica.stackexchange.com/questions/180/how-to-find-the-position-of-elements-in-a-list-satisfying-criteria
Say I have a list x=2,4,6,8,10 and I want to find out the positions of the elements that are greater than 7.
Select[x, #>7&] gives the elements themselves, and Position[x,8] gives the ...
- asked by PeterR (24 votes), answered by Guess who it is. (19 votes)
================================== Can you answer these? ==================================
[Arrowhead becomes unattached to line in a Graphics3D Manipulate]http://mathematica.stackexchange.com/questions/81306/arrowhead-becomes-unattached-to-line-in-a-graphics3d-manipulate
I’m trying to Manipulate a Graphics3D figure, and am seeing some errors. If I execute the following code, and move the slider, the head on one of arrows bounces around, unattached to the line of the ...
- asked by rhomboidRhipper (2 votes)
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[How to define \(\operatorname {Mc}\) and \(\operatorname {Ms}\) Mathieu functions in terms of MathieuC and MathieuS?] http://mathematica.stackexchange.com/questions/81395/how-to-define-operatornamemc-and-operatornamems-mathieu-functions-in-t
Reading multiple books about Mathieu functions, I always come across notation like \(\operatorname {ce}_r(z,q)\), \(\operatorname {se}_r(z,q)\) for angular functions and \(\operatorname {Ce}_r(z,q)\), ...
- asked by Ruslan (2 votes)
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[Partial Differential Formatting by default] http://mathematica.stackexchange.com/questions/82629/partial-differential-formatting-by-default
I read
http://blog.wolfram.com/2011/12/15/mathematica-qa-series-converting-to-conventional-mathematical-typesetting/
and I could use pdConv mentioned there, or
pdConv[f_] := TraditionalForm[ f ...
- asked by Hojin Cho (1 vote)
================================== Top new questions this week: ==================================
[Removing a histogram’s vertical edges]http://mathematica.stackexchange.com/questions/80949/removing-a-histograms-vertical-edges
Let’s say I have a histogram:
Histogram[RandomVariate[NormalDistribution[10, 2], 500]]
How can I remove vertical lines inside the histogram and keep only the edge?
- asked by moso (18 votes), answered by halirutan (12 votes)
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[Generating animations of clouds with Mathematica]http://mathematica.stackexchange.com/questions/80486/generating-animations-of-clouds-with-mathematica
I’d like to generate some visually-pleasing animations of clouds, fog or smoke with Mathematica. My idea of "visually-pleasing" is along the lines of one of the images on the Wikipedia article for ...
- asked by blochwave (17 votes), answered by Simon Woods (18 votes)
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[Better way to visualize cylinder puzzle solution]http://mathematica.stackexchange.com/questions/80902/better-way-to-visualize-cylinder-puzzle-solution
The above puzzle has been a recent source of amusement in my clique.
I decided to provide a visualization to motivate solution (here):
My code:
s[x_] := Piecewise[{{4 Mod[x, 3]/3, ...
- asked by ubpdqn (13 votes), answered by Jens (21 votes)
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[Mathematica 10.1.0.0 (OS X) high CPU usage even for empty notebook]http://mathematica.stackexchange.com/questions/80630/mathematica-10-1-0-0-os-x-high-cpu-usage-even-for-empty-notebook
Since update to 10.1.0.0 Mathematica has a high CPU usage even when no evaluation is running (even for empty notebook opened). I am running OS X Yosemite 10.10.3 on the following configuration:
...
- asked by Honza Drchal (11 votes), answered by BlBl (0 votes)
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[Right Ascension and Declination in astronomical functions] http://mathematica.stackexchange.com/questions/80787/right-ascension-and-declination-in-astronomical-functions
In the process of answering this question, I was forced to confront the various astronomical coordinate systems used by Mathematica.
Background
In astronomy, positions of celestial objects (stars, ...
- asked by Virgil (10 votes), answered by Virgil (12 votes)
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[Can’t inject EncryptedObject] http://mathematica.stackexchange.com/questions/80763/cant-inject-encryptedobject
Here are minimal examples:
encryptedObj = Encrypt["pass", "TestCase"]; Decrypt["pass", encryptedObj] (*returns correct "TestCase"*) With[{x = encryptedObj}, Button["Try with", Decrypt["pass", ...
- asked by Kuba (10 votes), answered by WReach (7 votes)
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[Difference between Fitting Algorithms] http://mathematica.stackexchange.com/questions/80998/difference-between-fitting-algorithms
I am new to Mathematica, and I don’t quite understand, what the difference between the fitting algorithms Fit, FindFit, LinearModelFit, NonLinearModelFit are. Why is the syntax so different (\(1,x,x^2\) ...
- asked by Luca Thiede (9 votes), answered by MarcoB (10 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make Jacobian automatically in Mathematica] http://mathematica.stackexchange.com/questions/5790/how-to-make-jacobian-automatically-in-mathematica
If we have two vectors, a and b, how can I make Jacobian matrix automatically in Mathematica?
$$ a=\left( \begin{array}{c} \text{x1}^3+2\text{x2}^2 \\ 3\text{x1}^4+7\text{x2} \end{array} $$
- asked by George Mills (19 votes), answered by Jens (26 votes)
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[Is there an open source implementation of Mathematica-the-language?] http://mathematica.stackexchange.com/questions/4454/is-there-an-open-source-implementation-of-mathematica-the-language
I’ve seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ...
- asked by sblom (59 votes), answered by Simon (50 votes)
================================== Can you answer these? ==================================
[Easy FindMaximum returns a wrong answer] http://mathematica.stackexchange.com/questions/81065/easy-findmaximum-returns-a-wrong-answer
FindMaximum in region is a new function in mma10,but when I tried the following example:
region = Polygon[{{0, 0}, {10, 0}, {10, 5}, {5, 5}, {5, 10}, {0, 10}}] FindMaximum[{x + y, {x, y} \[Element] ...
- asked by WateSoyan (2 votes)
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[Diverging solution to coupled second order ODEs from NDSolve] http://mathematica.stackexchange.com/questions/80692/diverging-solution-to-coupled-second-order-odes-from-ndsolve
For a physics application I am considering the radial Bogoliubov-de Gennes equations in two dimensions. In dimensionless form they read as follows
$$ \begin{cases} ...
- asked by Funzies (3 votes)
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[Does "FiniteRingData" or something like that exists?] http://mathematica.stackexchange.com/questions/81009/does-finiteringdata-or-something-like-that-exists
I want to find a function like FiniteGroupData but for finite rings. Does something like that exists?
- asked by kp9r4d (1 vote)
================================== Top new questions this week: ==================================
[Bug in MovingMap (breaking change between version 10.1 and 10.0.2)?] http://mathematica.stackexchange.com/questions/79931/bug-in-movingmap-breaking-change-between-version-10-1-and-10-0-2
The MovingMap window spec has been changed between version 10.1 and 10.0.2.
Version 10.0.2
MovingMap[h, a, b, c, d, e, f, 2] (* h[a, b], h[b, c], h[c, d], h[d, e], h[e, f] *)
Here we ...
- asked by Edmund (18 votes), answered by Stefan R (9 votes)
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[Analogue for Maple’s dchange - change of variables in differential expressions] http://mathematica.stackexchange.com/questions/80241/analogue-for-maples-dchange-change-of-variables-in-differential-expressions
Maple owns an interesting function called dchange which can change the variables of differential equations, but there seems to be no such function in Mathematica.
Has any one ever tried to write ...
- asked by xzczd (16 votes), answered by Kuba (18 votes)
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[Finding the period of an array of integers] http://mathematica.stackexchange.com/questions/80163/finding-the-period-of-an-array-of-integers
A simple array of integers is given. The problem is to detect if a pattern is repeatedly occurring in the array, and find the length of that pattern.
For example, for
19, 6, 19, 6, 19, 6, 19, 6, ...
- asked by VividD (12 votes), answered by Chris Degnen (6 votes)
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[How to have one or multiple Boxed graphics, mixed with non Boxed, in the same Graphics3D] http://mathematica.stackexchange.com/questions/80380/how-to-have-one-or-multiple-boxed-graphics-mixed-with-non-boxed-in-the-same-gr
In the following example, I would like to Boxed only the RegionPlot3D, and not the Sphere.
That is, to obtain this:
instead of this:
Here’s the sample code:
Show[ RegionPlot3D[x^2 + y^3 - ...
- asked by P. Fonseca (8 votes), answered by kguler (3 votes)
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[How to access an already opened Excel file in Mathematica?] http://mathematica.stackexchange.com/questions/80186/how-to-access-an-already-opened-excel-file-in-mathematica
This post 4594 shows how to open a existent Excel file with Mathematica. And this 6686886 shows how to do what I need, but in C#. This 12282310 is another related one.
How can I connect to a ...
- asked by Murta (8 votes), answered by Murta (8 votes)
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[JoinAcross on nested association by nested key] http://mathematica.stackexchange.com/questions/80311/joinacross-on-nested-association-by-nested-key
I would like to join two associations on nested keys. Is this possible?
first = {<|"away" -> <|"name" -> "bob", "money" -> 10 |>, "home" -> <|"name" -> "Sue", "money" ...
- asked by Ray Troy (7 votes), answered by WReach (8 votes)
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[How to synchronize the display of dynamic objects?] http://mathematica.stackexchange.com/questions/80027/how-to-synchronize-the-display-of-dynamic-objects
I was looking at this question, which asks to keep the orientation of some 3D graphics objects constant (relative to the viewer) while rotating the rest with the mouse. I thought that maybe the ...
- asked by Szabolcs (7 votes), answered by Gerli (3 votes)
================================== Greatest hits from previous weeks: ==================================
[How do I draw a pair of buttocks?] http://mathematica.stackexchange.com/questions/66538/how-do-i-draw-a-pair-of-buttocks
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
- asked by Simpleton Jack (214 votes), answered by mikuszefski (335 votes)
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[Plotting Complex Quantity Functions] http://mathematica.stackexchange.com/questions/3458/plotting-complex-quantity-functions
Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ...
- asked by night owl (15 votes), answered by Artes (16 votes)
================================== Can you answer these? ==================================
[MoonPosition and TimeZone support] http://mathematica.stackexchange.com/questions/80269/moonposition-and-timezone-support
With this question, I noticed some some weird results of MoonPosition. Consider the following code:
dateSunEclipse = DateObject[{2015,03,20,10,32,09},TimeZone->1]; dateSunEclipse0 = ...
- asked by unlikely (5 votes)
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[I can create an H2 database with the H2 Console, but I can’t find the database with MMA] http://mathematica.stackexchange.com/questions/80408/i-can-create-an-h2-database-with-the-h2-console-but-i-cant-find-the-database-w
I can create an H2(Server) database using the tool that H2 provides,
but although i can create a memory based H2 database with the Database Explorer, when I try to create a connection to the ...
- asked by George Wolfe (1 vote)
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[Empty Blank regression in v10.1] http://mathematica.stackexchange.com/questions/80090/empty-blank-regression-in-v10-1
In v10.1.0.0 on Linux, when Blank[] is used in Alternatives with pattern that can match a sequence, whole pattern unexpectedly matches sequences of any length.
ClearAll[matchLists] matchLists[patt_] ...
- asked by jkuczm (5 votes)
================================== Top new questions this week: ==================================
[many indefinite integrals do not evaluate in 10.1, looking for the cause] http://mathematica.stackexchange.com/questions/79367/many-indefinite-integrals-do-not-evaluate-in-10-1-looking-for-the-cause
Many integrals no longer evaluate in V 10.1 when they did in 10.0.2
Here are some 23 integrals as an example, that all produced results in V 10.0.2, but now all returns unevaluated!
I am hoping ...
- asked by Nasser (19 votes)
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[Why does a comma insert a line break in a comment?] http://mathematica.stackexchange.com/questions/79463/why-does-a-comma-insert-a-line-break-in-a-comment
I like to include capital letters and punctuation in my comments. But when I put a comma into a Mathematica comment of the (* ... *) type, it usually causes the comment line to break, with a new line ...
- asked by Ralph Dratman (17 votes), answered by sacratus (7 votes)
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[Why do lookup times in Dataset and Association differ by orders of magnitude?] http://mathematica.stackexchange.com/questions/79522/why-do-lookup-times-in-dataset-and-association-differ-by-orders-of-magnitude
Consider the following three data structures: a list of rules, an association, and a dataset:
n = 1000000; list = (ToString[#] -> #) & /@ Range[n]; assoc = Association@list; dataset = ...
- asked by verse (14 votes), answered by WReach (10 votes)
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[How to get the directory of a package?] http://mathematica.stackexchange.com/questions/79510/how-to-get-the-directory-of-a-package
I have a package that I have placed in the $BaseDirectory
Applications directory so that Needs can find it. I have a logo in the directory that I will
return when a function is called. However, when ...
- asked by Edmund (10 votes), answered by Szabolcs (10 votes)
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[RegionPlot returning a number] http://mathematica.stackexchange.com/questions/79572/regionplot-returning-a-number
Introduced in 10.0, persists in 10.1.
I had updated my mathematica to version 10 few days ago. And I had been shocked by the following fact:
s = FunctionInterpolation[Sin[x], x, 0, 1]; ...
- asked by WateSoyan (10 votes)
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[Why does Plot try symbolic values?] http://mathematica.stackexchange.com/questions/79573/why-does-plot-try-symbolic-values
I have the following code:
Test[a_] := (Print[a]; a*2) Plot[Test[a], {a, 0, 10}, PlotPoints -> 5, MaxRecursion -> 0]
This should plot a*2 for five points between a = 0 and a = 10, and print ...
- asked by Matthew (10 votes), answered by Simon Woods (9 votes)
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[Most efficient way of making pair list from a list] http://mathematica.stackexchange.com/questions/79622/most-efficient-way-of-making-pair-list-from-a-list
I have a bunch of datasets which looks like:
3 7 1 6 5 8 2 4 1 2 8 1 5 2 5 ...
and I need to make a list of pairs such that the first element makes a pair with other elements in the same line.
3 7 ...
- asked by Mahdi (9 votes), answered by Kuba (11 votes)
================================== Greatest hits from previous weeks: ==================================
[List of compilable functions] http://mathematica.stackexchange.com/questions/1096/list-of-compilable-functions
Is there somewhere a list on the functions that Compile can compile, or the cases in which a particular function can be compiled that I haven’t found? I’d be glad even with a list of some of them ...
- asked by Rojo (83 votes), answered by Oleksandr R. (92 votes)
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[How to use Mathematica functions in Python programs?] http://mathematica.stackexchange.com/questions/4643/how-to-use-mathematica-functions-in-python-programs
I’d like to know how can I call Mathematica functions from Python.
I appreciate a example, for example, using the Mathematica function Prime.
I had search about MathLink but how to use it in Python ...
- asked by GarouDan (29 votes), answered by GarouDan (11 votes)
================================== Can you answer these? ==================================
[Strange Integrate messages $RecursionLimit being ignored] http://mathematica.stackexchange.com/questions/79801/strange-integrate-messages-recursionlimit-being-ignored
Introduced in 10.1.0
The following behavior was observed in Mathematica 10.1 (Windows 64 bit)
When attempting to evaluate the following integral, Mathematica outputs several messages which appear ...
- asked by Nick (2 votes)
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[ListConvolve Memory Hemorrhage] http://mathematica.stackexchange.com/questions/79340/listconvolve-memory-hemorrhage
I wrote a routine that convolves an impulse response array with a test array and checks for the RMS difference between that convolution and a data array. I do this iteratively so that I can modify the ...
- asked by A. McEvoy (6 votes)
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[SystemException[MemoryAllocationFailure] with Memoized function] http://mathematica.stackexchange.com/questions/79378/systemexceptionmemoryallocationfailure-with-memoized-function
Version 10.1 Win7x64 Enterprise.
This is more of a report than a question but others may have seen the same / have insights.
I have some code (that I can’t really post as it’s too big) with a large ...
- asked by Ymareth (1 vote)
================================== Top new questions this week: ==================================
[String-manipulation bugs in v10.1] http://mathematica.stackexchange.com/questions/78884/string-manipulation-bugs-in-v10-1
The new version 10.1 has introduced some strange (possibly buggy) behaviour compared to v10.0:
StringCases["1472", Except["0", DigitCharacter]]
(* v10.0 *) "1","4","7","2" (* v10.1 *) "1"
...
- asked by Istvan Zachar (25 votes), answered by Stefan R (8 votes)
—————————-
[What are the cool kids talking about when they use ##&[]
?]
http://mathematica.stackexchange.com/questions/78910/what-are-the-cool-kids-talking-about-when-they-use
All the cool kids are apparently using
##&[]
for
Unevaluated @ Sequence[]
but I have no idea what either means.
Please explain what these things are so I can be a cool kid!
- asked by raxacoricofallapatorius (23 votes), answered by rasher (18 votes)
—————————-
[Mathematical morphology: removing text features from image, while keeping connectivity] http://mathematica.stackexchange.com/questions/79066/mathematical-morphology-removing-text-features-from-image-while-keeping-connec
I have this image of London’s road networks.
img = Image[ Import["https://maps.googleapis.com/maps/api/staticmap?center=+51.5+ ...
- asked by andandandand (17 votes), answered by mm.Jang (12 votes)
—————————-
[What is the difference between Composition (@*) and sequential applications (@)?] http://mathematica.stackexchange.com/questions/78979/what-is-the-difference-between-composition-and-sequential-applications
What is the difference between
f@*g@*h@x
and
f@g@h@x
Both evaluate to
f[g[h[x]]]
If they’re the same, why introduce Composition as a new feature?
- asked by raxacoricofallapatorius (15 votes), answered by Szabolcs (22 votes)
—————————-
[Random polyhedra walk] http://mathematica.stackexchange.com/questions/79099/random-polyhedra-walk
I would like to recreate ssch’s random polyhedra random walk, which he posted in the chat. For convenience here it is again:
Since it’s been one and a half year since then I’ve certainly had time ...
- asked by Pickett (14 votes)
—————————-
[Plot a partition of the sphere given vertices of polygons] http://mathematica.stackexchange.com/questions/78705/plot-a-partition-of-the-sphere-given-vertices-of-polygons
I saw in this question that Mathematica can draw spherical triangles. I guess something similar can be done to plot a spherical polygon. I am interested in something similar:
I have a set of ...
- asked by Beni Bogosel (12 votes), answered by Taiki (14 votes)
—————————-
[Why is a symbol still found after changing its context?] http://mathematica.stackexchange.com/questions/78926/why-is-a-symbol-still-found-after-changing-its-context
It seems that we can change the context of symbols:
In[1]:= x = 1 Out[1]= 1
In[2]:= Context[x] = "foo‘";
But then x is still interpreted as foo‘x (and not Global‘x) even though foo‘ is not in ...
- asked by Szabolcs (8 votes), answered by penguin77 (0 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J.M. (339 votes), answered by faysou (314 votes)
—————————-
[How do I draw a pair of buttocks?] http://mathematica.stackexchange.com/questions/66538/how-do-i-draw-a-pair-of-buttocks
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
- asked by Simpleton Jack (212 votes), answered by mikuszefski (333 votes)
================================== Can you answer these? ==================================
[short cut entry in KeyEventTranslations.tr works on V 10.0.2 but does not work in V 10.1] http://mathematica.stackexchange.com/questions/79195/short-cut-entry-in-keyeventtranslations-tr-works-on-v-10-0-2-but-does-not-work-i
I added 2 useful key shortcuts to my V 10.0.2 KeyEventTranslations.tr to allow adding [[ and ]] using ctrl-[ and ctrl-] (thanks to this post by Szabolcs at WRI community some time ago) and these ...
- asked by Nasser (1 vote)
—————————-
[Compile, "global variables" and recursion] http://mathematica.stackexchange.com/questions/78768/compile-global-variables-and-recursion
I am trying to do something similar to this, namely to make a Compile’d function outer that itself calls a Compile’d function inner which accesses a variable defined in outer. Copy-pasting the example ...
- asked by Marius Ladegard Meyer (3 votes)
—————————-
[Issues reproducing reversible CA from NKS] http://mathematica.stackexchange.com/questions/78931/issues-reproducing-reversible-ca-from-nks
I want to recreate the output of the reversible cellular automaton described in this page of the NKS book.
The book specifies that this is a modified version of R214, where the new state (step+1) ...
- asked by andandandand (1 vote)
================================== Top new questions this week: ==================================
[How to sort digits in a string while keeping other characters untouched?] http://mathematica.stackexchange.com/questions/78464/how-to-sort-digits-in-a-string-while-keeping-other-characters-untouched
Now there is a string with digits and letters, for instance, "95uge678r3gi89hgfe30kgh063d51". And the expected output is "00uge133r3gi55hgfe66kgh788d99".
I am able to do it in this way
...
- asked by Felix (12 votes), answered by Mr.Wizard (8 votes)
—————————-
[Expansion of a hypergeometric function takes ages with Mathematica 9 and 10 (regression?)] http://mathematica.stackexchange.com/questions/78534/expansion-of-a-hypergeometric-function-takes-ages-with-mathematica-9-and-10-reg
Mathematica 8 (Linux version) can evaluate
AbsoluteTiming[Series[Hypergeometric2F1[1, 1 - eps/2, 3 - eps, 1/2], eps, 0, 0]]
in no time. On one of the university machines the result is
0.175840, ...
- asked by vsht (10 votes), answered by Eric Towers (4 votes)
—————————-
[Opposite of StringSplit]http://mathematica.stackexchange.com/questions/78405/opposite-of-stringsplit
What is an appropriate command that does the opposite of the following.
StringSplit["a b c d e f g"," "]
- asked by William (10 votes), answered by Pickett (16 votes)
—————————-
[Why can I not replace a Dataset using a rule?]http://mathematica.stackexchange.com/questions/78131/why-can-i-not-replace-a-dataset-using-a-rule
Simple replacement of a Dataset object does not seem to follow the expected behavior...
Dataset[{}] /. _Dataset->1
Returns the empty Dataset not 1 as I would have expected.
Whereas...
- asked by Ymareth (9 votes), answered by WReach (11 votes)
—————————-
[Turning a set of random walk data 45 degrees] http://mathematica.stackexchange.com/questions/78347/turning-a-set-of-random-walk-data-45-degrees
I have a set of data that is just a "random" (generated by me, not by computer) sequence of length 2000 of 1’s and (-1)’s. I used it to plot a 1-D random walk where +1 is step up, (-1) is step down, ...
- asked by Solarmew (8 votes), answered by Karsten 7. (4 votes)
—————————-
[Unexpected slowness checking for empty list?] http://mathematica.stackexchange.com/questions/78155/unexpected-slowness-checking-for-empty-list
I thought I had a firm understanding of the differences between Equal and SameQ, but this has me puzzled:
test = RandomInteger[100000000, 10000000]; == test // AbsoluteTiming === test // ...
- asked by rasher (8 votes), answered by Mr.Wizard (9 votes)
—————————-
[Mathematica on Raspberry Pi] http://mathematica.stackexchange.com/questions/78319/mathematica-on-raspberry-pi
Can I develop BSD/MIT open-source library for Mathematica using free non-commercial version on Raspberry Pi?
To state it differently: does the non-commercial limitation of Mathematica on RPi limit ...
- asked by denfromufa (7 votes), answered by denfromufa (3 votes)
================================== Greatest hits from previous weeks: ==================================
[Divide all but the maximal element in a list by 10?]http://mathematica.stackexchange.com/questions/69547/divide-all-but-the-maximal-element-in-a-list-by-10
I have a list of numerical data, and I want to write a program that will keep the maximum as it is, but reduce the rest by certain factor (such as 10). For example:
input = 2, 3, 1, -3, -5, 9, 2, 6, ...
- asked by Paul (13 votes), answered by WReach (20 votes)
—————————-
[Division by zero is slow]http://mathematica.stackexchange.com/questions/64247/division-by-zero-is-slow
Suppose I have two arrays of data, which I want to divide:
n = 1000; a = RandomInteger[1, 9, n, n]; b = RandomInteger[1, 9, n, n]; First @ AbsoluteTiming @ (a/b)
0.637064
But suppose ...
- asked by wxffles (12 votes), answered by Michael E2 (6 votes)
================================== Can you answer these? ==================================
[Display of ConfusionMatrixPlot depends on Stylesheet] http://mathematica.stackexchange.com/questions/78229/display-of-confusionmatrixplot-depends-on-stylesheet
I’m using Classify and do the testing via ClassifierMeasurements. Now I observed that ConfusionMatrixPlot is not shown correctly when using StyleSheet Report(default). Maybe you can reproduce (example ...
- asked by mgamer (2 votes)
—————————-
[How to restart a Clock] http://mathematica.stackexchange.com/questions/78677/how-to-restart-a-clock
The code below is to demonstrate color afterimages. The user chooses a color, fixates the changing numbers at the center until they reach 30 (seconds), then manually switches to white to observer the ...
- asked by abwatson (1 vote)
—————————-
[NDSolve Poisson PDE for rectangle with hole] http://mathematica.stackexchange.com/questions/78624/ndsolve-poisson-pde-for-rectangle-with-hole
When I solved the Poisson PDE with function NDSolve in a rectangular domain with hole in the center, and search the first derivative with x and y why appear these protrusions on the diagram around the ...
- asked by wlkyr (1 vote)
================================== Top new questions this week: ==================================
[Faster position list construction from a "take instructions" list] http://mathematica.stackexchange.com/questions/77542/faster-position-list-construction-from-a-take-instructions-list
Take some list, e.g., 1,2,3,4,5, and a "take instructions" list, say 1,1,2,1,1.
The latter is read as "take the first element from the list, drop it from the list, take the first element of the ...
- asked by rasher (16 votes), answered by 2012rcampion (9 votes)
—————————-
[Capturing Data from an Android Phone] http://mathematica.stackexchange.com/questions/77514/capturing-data-from-an-android-phone
Is there a way to capture Data from an android phone to be later analyzed in Mathematica?
- asked by Zviovich (10 votes), answered by Zviovich (10 votes)
—————————-
[Match opening and closing parentheses?] http://mathematica.stackexchange.com/questions/77779/match-opening-and-closing-parentheses
Suppose I have a List of the form:
lst="(", "(", "(", ")", "(", ")", ")", ")"
By running Position[lst, "("] and Position[lst, ")"], I can get the positions of the opening and closing parentheses ...
- asked by becko (8 votes), answered by Simon Woods (12 votes)
—————————-
[Segmenting Sections of Lines in an Image] http://mathematica.stackexchange.com/questions/77972/segmenting-sections-of-lines-in-an-image
I have taken several gps readings while driving around town.
gpsPositions=GeoPosition[33.657, -84.5197, 33.6687, -84.4977, 33.692, -84.4907, 33.7057, -84.4287, 33.7431, -84.4027, ...
- asked by Zviovich (7 votes), answered by nikie (8 votes)
—————————-
[Flatten nested lists]http://mathematica.stackexchange.com/questions/78030/flatten-nested-lists
I have a list as follows
lis= a, b, c,d,e, f, g,h,i
which I would like to flatten to
flattenLis=a,b,c,d,e,f,g,h,i
Does anyone have a hint. All my flatten attempts did not ...
- asked by Phadreus (7 votes), answered by Kuba (7 votes)
—————————-
[How to make a binary function associative? (Or define an n-ary function?)]http://mathematica.stackexchange.com/questions/77913/how-to-make-a-binary-function-associative-or-define-an-n-ary-function
Suppose I have a simple function that I assign to an operator
f[a_, b_] := a + b CirclePlus = f
Then I want to write
1 (+) 2 (+) 3
But it doesn’t work, because it’s trying to evaluate f[1,2,3].
...
- asked by Noon Silk (7 votes), answered by halirutan (9 votes)
—————————-
[Strange answer from StringReplace] http://mathematica.stackexchange.com/questions/77771/strange-answer-from-stringreplace
I have a list of strings and I would check if there is an empty string element, that’s "", because I need to replace it with a "0". I try the following
StringReplace[{"90", "", "20"}, "" -> "0"]
...
- asked by bobknight (7 votes), answered by Sjoerd C. de Vries (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to use Mathematica functions in Python programs?] http://mathematica.stackexchange.com/questions/4643/how-to-use-mathematica-functions-in-python-programs
I’d like to know how can I call Mathematica functions from Python.
I appreciate a example, for example, using the Mathematica function Prime.
I had search about MathLink but how to use it in Python ...
- asked by GarouDan (28 votes), answered by GarouDan (10 votes)
—————————-
[A one line proof that one is zero using Mathematica 10] http://mathematica.stackexchange.com/questions/65624/a-one-line-proof-that-one-is-zero-using-mathematica-10
a = (Sqrt[2] + 1) (Sqrt[2] - 1) - 1; a/a, Simplify[a]/a, b/b == Simplify[b]/b
1, 0, True
This one line "proof" that one equals zero is disturbing (and could possibly lead to wrong results ...
- asked by Gregoire Nicollier (11 votes), answered by Szabolcs (24 votes)
================================== Can you answer these? ==================================
[How to simplify an expression with a radical sign nesting in a radical sign] http://mathematica.stackexchange.com/questions/77902/how-to-simplify-an-expression-with-a-radical-sign-nesting-in-a-radical-sign
Is there a function can simplify an expression with a radical sign nesting in a radical sign in Mathematica? I use V9.
RatDenmon is a function that can rationalize the denominator.
- asked by user27189 (1 vote)
—————————-
[Plotting data with four variables; two labels for one of the axes] http://mathematica.stackexchange.com/questions/77727/plotting-data-with-four-variables-two-labels-for-one-of-the-axes
I am having difficulty related to 3D plotting task. I have a set of data points in the following form :
data=1x, 1y1,1y2,1z, 2x,2y1,2y2,2z,....nx,ny1,ny2,nz
The set of points ...
- asked by user91411 (2 votes)
—————————-
[Lisp Interpreter] http://mathematica.stackexchange.com/questions/77661/lisp-interpreter
What is the cleanest way to build a lisp interpreter inside Mathematica.
I’m not looking for all the functions to be implemented but instead just the basic syntax.
- asked by William (3 votes)
================================== Top new questions this week: ==================================
[White balance correction with Mathematica] http://mathematica.stackexchange.com/questions/77235/white-balance-correction-with-mathematica
Does Mathematica include a function to correct the white balance of an image? ImageAdjust would seem to be the first go-to choice, but I haven’t found a way to correct white balance without changing ...
- asked by shrx (12 votes), answered by Karsten 7. (11 votes)
—————————-
[Inline documentation of "Properties"] http://mathematica.stackexchange.com/questions/77056/inline-documentation-of-properties
Context
I find the documentation has become a bit of a maze, in particular given the more recent convention of having keywords has strings rather than Mathematica Keywords.
For instance,
...
- asked by chris (10 votes), answered by halirutan (15 votes)
—————————-
[What is the fastest way to get the nth distinct permutation of a list?] http://mathematica.stackexchange.com/questions/77443/what-is-the-fastest-way-to-get-the-nth-distinct-permutation-of-a-list
What is the fastest way to write a function nthPermutation[xs_List, n_Integer] which is equivalent to Permutations[xs][[n]] but does not explicitly compute all the permutations of xs? This feature ...
- asked by David Zhang (8 votes), answered by 2012rcampion (6 votes)
—————————-
[Area of Self-Intersecting Polygon with Repeated Vertices] http://mathematica.stackexchange.com/questions/76999/area-of-self-intersecting-polygon-with-repeated-vertices
So Mathematica uses an even-odd rule for self-intersecting polygons, both when rendering them and when calculating their area:
poly = Polygon@0., 0, 3, 0, 3, 2, 1, 2, 1, 1, 2, 1, 2, 3, ...
- asked by Martin Buttner (8 votes), answered by Michael E2 (7 votes)
—————————-
[Why does cropping an image improve TextRecognize so much?] http://mathematica.stackexchange.com/questions/76993/why-does-cropping-an-image-improve-textrecognize-so-much
I am trying to use the TextRecognize function to extract data from certain screenshots. This is already a cropped version.
Using TextRecognize on this yields 12 Catherine FicktEuSC|'\A|V|K. Not ...
- asked by timvermeulen (8 votes)
—————————-
[How to evaluate a function on a list until stable?] http://mathematica.stackexchange.com/questions/77403/how-to-evaluate-a-function-on-a-list-until-stable
I need to evaluate a function func on a range of integers (NOT recursively, just sequentially) until the result is stable enough. I can write a not very clever step-by-step program using While:
...
- asked by Ziofil (7 votes), answered by Pickett (6 votes)
—————————-
[How to programmatically covert a function-like rule to a pure function?] http://mathematica.stackexchange.com/questions/77436/how-to-programmatically-covert-a-function-like-rule-to-a-pure-function
Is there a programmatic way to convert a Mathematica rule that acts like a typical mathematical function of one variable into the equivalent pure function? For example, the code should convert
f[x_] ...
- asked by ibeatty (7 votes), answered by rasher (7 votes)
================================== Greatest hits from previous weeks: ==================================
[List of compilable functions] http://mathematica.stackexchange.com/questions/1096/list-of-compilable-functions
Is there somewhere a list on the functions that Compile can compile, or the cases in which a particular function can be compiled that I haven’t found? I’d be glad even with a list of some of them ...
- asked by Rojo (82 votes), answered by Oleksandr R. (91 votes)
—————————-
[Having used Mathematica as a "gateway" language, where to from here?] http://mathematica.stackexchange.com/questions/25702/having-used-mathematica-as-a-gateway-language-where-to-from-here
I have been using Mathematica for about a year. It is the first language that I have attempted to learn. I’m still very much a newbie, but there are moments I feel more like I am waving than drowning. ...
- asked by geordie (42 votes), answered by Leonid Shifrin (47 votes)
================================== Can you answer these? ==================================
[What is the "Origin" rule for in a Dataset?] http://mathematica.stackexchange.com/questions/77186/what-is-the-origin-rule-for-in-a-dataset
Take an innocuous Dataset.
d= Dataset[List[ Association[Rule["A","K1"],Rule["B",6.‘]], Association[Rule["A","K1"],Rule["B",1.‘]], Association[Rule["A","K2"],Rule["B",1.‘]], ...
- asked by Ymareth (1 vote)
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[Running Java with Wolfram Workbench on a parallel kernel] http://mathematica.stackexchange.com/questions/77137/running-java-with-wolfram-workbench-on-a-parallel-kernel
I’m trying to load my package on a parallel kernel while debugging in Wolfram Workbench 2.0. My project is set up as a Java project and parts of it use Java functions located in jar files. The java ...
- asked by faysou (1 vote)
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[Fitting data to a derivative model]http://mathematica.stackexchange.com/questions/77345/fitting-data-to-a-derivative-model
I just started using Mathematica. I would like to use Mathematica to do non-linear regression. My model equation is :
...
- asked by Asd (1 vote)
================================== Top new questions this week: ==================================
[Different floating-point numbers equal?] http://mathematica.stackexchange.com/questions/76896/different-floating-point-numbers-equal
Let’s define two different numbers.
x = 1. y = 1. + 2^-52 (* equivalently, 1 + $MachineEpsilon *) Let's make sure they're different with FullForm: x // FullForm (* 1.` *) y // FullForm (* ...
- asked by 2012rcampion (12 votes), answered by Karsten 7. (8 votes)
—————————-
[Major slowdown when using a ColorFunction with more than one named scheme] http://mathematica.stackexchange.com/questions/76610/major-slowdown-when-using-a-colorfunction-with-more-than-one-named-scheme
Earlier Kuba noted a major slowdown with code Simon Woods posted. Here is a simplified example.
First a color function using two different named gradient schemes:
fn = ColorData[If[# < 0.5, ...
- asked by Mr.Wizard (12 votes), answered by Mr.Wizard (15 votes)
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[Min, Max are slow on TimeObjects]http://mathematica.stackexchange.com/questions/76652/min-max-are-slow-on-timeobjects
There’s something wrong with how Min and Max are implemented for TimeObject:
times = TimeObject[List[0, 14, 55.99‘]], TimeObject[List[0, 14, 57.8‘]], TimeObject[List[0, 14, 59.09‘]], ...
- asked by alancalvitti (12 votes), answered by Mr.Wizard (10 votes)
—————————-
[How to properly inject iterators into table?]http://mathematica.stackexchange.com/questions/76917/how-to-properly-inject-iterators-into-table
Goofing off on a prior question, I was fiddling with other methods, which led me to the need to inject a constructed set of iterators into a table construct.
Now,
ClearAll[a, b, z, z2]
z = a, 2, ...
- asked by rasher (8 votes), answered by Kuba (7 votes)
—————————-
[How to make a movie from a complex demonstration?]http://mathematica.stackexchange.com/questions/76832/how-to-make-a-movie-from-a-complex-demonstration
I have a complex Manipulate-based demonstration containing a few sliders and a Setterbar.
I would like to make a movie out of it, avi, or whatever else. The movie will then be used for a journal ...
- asked by Alexei Boulbitch (8 votes), answered by Karsten 7. (6 votes)
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[Mathematica not honoring the distributive property of multiplication?] http://mathematica.stackexchange.com/questions/76457/mathematica-not-honoring-the-distributive-property-of-multiplication
Reduce[ ForAll[ multiplicant, summandA, summandB, Element[multiplicant, summandA, summandB, Reals], multiplicant*summandA - multiplicant*summandB == multiplicant*(summandA - ...
- asked by gaazkam (8 votes), answered by Adam Strzebonski (10 votes)
—————————-
[How to Map a function with HoldAll attribute]http://mathematica.stackexchange.com/questions/76558/how-to-map-a-function-with-holdall-attribute
First of all, I’m not sure about the title of this question, so please correct me if there is any title more sensible than mine. The problem is the following: I have a function f that checks if a ...
- asked by bobknight (7 votes), answered by kguler (5 votes)
================================== Greatest hits from previous weeks: ==================================
[How to make use of Associations?]http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (71 votes), answered by Leonid Shifrin (71 votes)
—————————-
[How to create a new "person curve"?] http://mathematica.stackexchange.com/questions/17704/how-to-create-a-new-person-curve
Wolfram|Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica notebook, or person curve into ...
- asked by Simon (49 votes), answered by Vitaliy Kaurov (21 votes)
================================== Can you answer these? ==================================
[How to force the writing of buffers onto disk?]http://mathematica.stackexchange.com/questions/76351/how-to-force-the-writing-of-buffers-onto-disk
Usually, buffering is good; except when you critically need to write data to disk. Is there a way to force the writing of buffers onto disk? (I’m using a binary file)
I believe a Close[ ] followed ...
- asked by richard (4 votes)
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[Trouble using Solve and NSolve with functions involving Erf]http://mathematica.stackexchange.com/questions/76429/trouble-using-solve-and-nsolve-with-functions-involving-erf
I have the following functions:
R[k_, x_, t_] := -.5*(k - x)*(1 + Erf[-(k - x)/t]) L[k_, c_, x_, t_] := .5*c*(k - x)*(1 + Erf[(k - x)/t])
I’m interested in finding the k that solves some equation ...
- asked by Pburg (1 vote)
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[Packages and Notebooks as a Databin]http://mathematica.stackexchange.com/questions/76474/packages-and-notebooks-as-a-databin
The new Data Drop product sounds interesting. Can I use Databin to share Packages and Notebooks?
If yes. How? Something like:
bin = CreateDatabin[] DatabinAdd[bin, <|"myPack" -> "???"|>]
...
- asked by Murta (1 vote)
================================== Top new questions this week: ==================================
[Finding a function that fits the shape of an image]http://mathematica.stackexchange.com/questions/75855/finding-a-function-that-fits-the-shape-of-an-image
How can I find a function that fits the given shape of an image? Or instead extract a point set from the shape and then find an interpolating function fits the shape.
An example image is attached.
- asked by Mikayel (12 votes), answered by belisarius (21 votes)
—————————-
[Adding Trace produces error messages]http://mathematica.stackexchange.com/questions/76082/adding-trace-produces-error-messages
This is very strange. As I was trying to debug this problem, I noticed when I add Trace then I get lots of internal errors generated. This also happens the first time after the kernel is started. ...
- asked by Nasser (11 votes), answered by WReach (9 votes)
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[How can I define or use a new coordinate system in Mathematica?]http://mathematica.stackexchange.com/questions/75815/how-can-i-define-or-use-a-new-coordinate-system-in-mathematica
I want to use the dipole coordinate system as defined in this paper: http://arxiv.org/abs/physics/0606044
I see that Mathematica can do all kinds of vector analysis using different kinds of ...
- asked by jvriesem (7 votes), answered by Itai Seggev (0 votes)
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[Inconsistent behavior of undocumented Encode->Import->StringToStream->Get on password-locked stream]http://mathematica.stackexchange.com/questions/76085/inconsistent-behavior-of-undocumented-encode-import-stringtostream-get-on-pas
Let’s save a definition. Encode it with password/key and Get it again.
We will not use Get directly on directory but with combination of Get+StringToStream+Import.
Get works with streams since V9.0 ...
- asked by Kuba (7 votes), answered by Jinxed (1 vote)
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[Ghost trails with Animate?]http://mathematica.stackexchange.com/questions/75936/ghost-trails-with-animate
What are some approaches to integrate Ghost trails methods with Animate, which otherwise seem more suited for exporting individual frames?
For example, given this rootPlot function, how can trails ...
- asked by alancalvitti (7 votes), answered by Pickett (9 votes)
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[how to build matrix from set of vectors and other matrices using ArrayFlatten]http://mathematica.stackexchange.com/questions/76311/how-to-build-matrix-from-set-of-vectors-and-other-matrices-using-arrayflatten
I want to build a 6 by 3 matrix, from the following: one vector is 3 by 1, then a matrix, which is 3 by 2. These will go to the top 3 rows. Now the bottom 3 rows, I’ll have 3 vectors each is 3 by 1. ...
- asked by Nasser (6 votes), answered by Kuba (5 votes)
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[Computing launch parameters for hitting a point in 3D with projectile under influence of wind]http://mathematica.stackexchange.com/questions/75945/computing-launch-parameters-for-hitting-a-point-in-3d-with-projectile-under-infl
The end goal of this problem is to compute functions which describe the launch parameters which are needed to hit a specified goal in 3D in the presence of wind disturbances. This is as far I have ...
- asked by Julian (6 votes), answered by belisarius (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Where can I find examples of good Mathematica programming practice?] http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J.M. (333 votes), answered by faysou (308 votes)
—————————-
[How do I draw a pair of buttocks?]http://mathematica.stackexchange.com/questions/66538/how-do-i-draw-a-pair-of-buttocks
I’m trying to develop a function which 3D plot would have a buttocks like shape.
Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ...
- asked by Simpleton Jack (209 votes), answered by mikuszefski (327 votes)
================================== Can you answer these? ==================================
[FindMinimum’s WorkingPrecision behaviour]http://mathematica.stackexchange.com/questions/76259/findminimums-workingprecision-behaviour
I discovered the following behaviour when using FindMinimum for constrained optimization:
Clear@f f[x_?NumericQ] := (Print@Precision@x; x^2) FindMinimum[{f[x], x < 1}, {x, 1}, WorkingPrecision ...
- asked by sebhofer (1 vote)
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[Font style in Mathematica and .tex file]http://mathematica.stackexchange.com/questions/76250/font-style-in-mathematica-and-tex-file
I am using Mathematica 8. I want to label the axes of figure in "Times" font.
Plot[Sin[z], {z, -2 Pi, 2 Pi}, Frame -> True, FrameLabel -> {"z", "a(z)"}, LabelStyle -> Directive[FontSize ...
- asked by zenith (3 votes)
—————————-
[ParametricNDSolveValue over a region]http://mathematica.stackexchange.com/questions/75887/parametricndsolvevalue-over-a-region
I’m getting the following behavior I don’t understand when using ParametricNDSolveValue over a region. You can reproduce the behavior considering Poisson’s equation as shown below
The below works as ...
- asked by user2162855 (1 vote)
Tuesday, February 24, 2015
================================== Top new questions this week: ==================================
[Can Mathematica’s random number generation be improved?]http://mathematica.stackexchange.com/questions/75303/can-mathematicas-random-number-generation-be-improved
Performance on Random Number generation is intolerable. Whenever you need many deviates from the same distribution but with different parameters it takes forever.
Here is a thread on Poisson ...
- asked by JEP (11 votes), answered by JEP (4 votes)
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[The efficiency compare between Flatten[#, 1] & and Join @@ #&
]
http://mathematica.stackexchange.com/questions/75590/the-efficiency-compare-between-flatten-1-and-join
Err..Often I met the situation to join lists at the first level and I used to just Flatten[#, 1] &@ them. However, I found(when glance over the mathematica.stackexchange.com) someone else prefer ...
- asked by Harry (11 votes), answered by Michael E2 (8 votes)
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[Is Mathematica ‘ContourPlot‘ function really so efficient?] http://mathematica.stackexchange.com/questions/75352/is-mathematica-contourplot-function-really-so-efficient
I wanted to find the roots of the function \(f(x,y)=\sin (3.2x)\sin (1.3y)-2.1 \sin (1.3x)\sin (3.2y)\). This is what the function looks like:
f[x_, y_] = Sin[3.2 x]*Sin[1.3*y] - 2.1*Sin[1.3*x]*Sin[3.2*y] ...
- asked by anderstood (11 votes), answered by george2079 (16 votes)
—————————-
[How to randomly select subsets]http://mathematica.stackexchange.com/questions/75431/how-to-randomly-select-subsets
I have a list of around 300 elements. I want to sample subsets of length 25 such that my samples are all distinct. My first inclination was to use something like RandomSample[Subsets[list, 25], ...
- asked by mtiano (7 votes), answered by Mr.Wizard (8 votes)
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[Prevent Export from overwriting files]http://mathematica.stackexchange.com/questions/75745/prevent-export-from-overwriting-files
Export["filepath1",Expression1] works for me, but if filepath1 already exists, it will be overwritten. I’d like Export to notify me and ask for a confirmation, if it tries to overwrite filepath1.
I ...
- asked by user1541776 (6 votes), answered by Mr.Wizard (11 votes)
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[How trustworthy is NMaximize?]http://mathematica.stackexchange.com/questions/75668/how-trustworthy-is-nmaximize
Suppose I solve a constrained optimisation problem using NMaximize. How confident can I be of the accuracy of the result?
For concreteness, suppose that F,G are (exactly known) functions (say, ...
- asked by Feanor (6 votes), answered by mikeagibson (8 votes)
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[Mathematica and POV-Ray workflow: ListContourPlot3D]http://mathematica.stackexchange.com/questions/75497/mathematica-and-pov-ray-workflow-listcontourplot3d
I have the following function describing a molecular electronic Orbital.
f[r_] = E^-((r - R0)/\[CapitalDelta]r)^2; r = Sqrt[x^2 + y^2 + z^2]; cosphi[x_, y_, z_] := If[x == 0 && y == 0 ...
- asked by DPengel (6 votes)
================================== Greatest hits from previous weeks: ==================================
[How to generate a random snowflake]http://mathematica.stackexchange.com/questions/39361/how-to-generate-a-random-snowflake
’Tis the season... And it’s about time I posed my first question on Mathematica Stack Exchange. So, here’s an holiday quest for you Graphics (and P-Chem?) gurus.
What is your best code for generating ...
- asked by Peltio (100 votes), answered by Silvia (132 votes)
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[Where can I find examples of good Mathematica programming practice?]http://mathematica.stackexchange.com/questions/18/where-can-i-find-examples-of-good-mathematica-programming-practice
I consider myself a pretty good Mathematica programmer, but I’m always looking out for ways to either improve my way of doing things in Mathematica, or to see if there’s something nifty that I haven’t ...
- asked by J.M. (333 votes), answered by faysou (308 votes)
================================== Can you answer these? ==================================
[Precision loss in FourierDCT]http://mathematica.stackexchange.com/questions/75292/precision-loss-in-fourierdct
I have high precision data that I want to do Fourier transform with, but it looks like the precision is lost dramatically.
data = ...
- asked by xslittlegrass (2 votes)
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[Can I use Mathematica 9.0 to open an MX file produced by Mathematica 10?]http://mathematica.stackexchange.com/questions/75581/can-i-use-mathematica-9-0-to-open-an-mx-file-produced-by-mathematica-10
I have used Mathematica 10 installed on a workstation of university’s lab to run a NDSlove code that produced a .mx file. Then I copy the .mx file to my laptop which has Mathematica 9.0. When I try to ...
- asked by lxy (1 vote)
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[Is it possible to circumvent this overflow?]http://mathematica.stackexchange.com/questions/75329/is-it-possible-to-circumvent-this-overflow
I’m trying to evaluate the following function numerically:
$ f(A,B)=\frac{2A\pi ^{5/2} (-1)^B}{(A!)^2B!} \, _4\tilde{F}_3\left({\frac{1}{2},1-A,1-A,1-B\atop ...
- asked by Ziofil (1 vote)
================================== Top new questions this week: ==================================
[Change Values in Dataset under Condition]http://mathematica.stackexchange.com/questions/74165/change-values-in-dataset-under-condition
I have the following Dataset:
ds = Dataset@*Map[AssociationThread[{"ID", "VAL1", "VAL2", "VAL3", "Type"} -> #] &]@ {{"C09", 18.5, 18.5, 18.5, "FE"}, {"C11", 21, 21, 21, "FE"}, {"C10", ...
- asked by Lea (10 votes), answered by WReach (6 votes)
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[Drawing a Gradient Between Two Circular Arcs]http://mathematica.stackexchange.com/questions/73928/drawing-a-gradient-between-two-circular-arcs
Suppose I wanted to use Mathematica graphics primitives to create a gradient of colors between two circular arcs. It’s easy enough to make an area between two circles a solid color, but what if I ...
- asked by Noah Rubin (10 votes), answered by ybeltukov (11 votes)
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[How to search Dataset to find all keys share same Value]http://mathematica.stackexchange.com/questions/74200/how-to-search-dataset-to-find-all-keys-share-same-value
If I have the following Dataset
ds=Dataset[{ <|"a" -> 1, "b" -> "x", "c" -> 6|>, <|"a" -> 2, "b" -> "y", "c" -> {2, 3}|>, <|"a" -> "x", "b" -> "z", "c" ...
- asked by Algohi (8 votes), answered by Leonid Shifrin (5 votes)
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[Windows command line arguments, stdin & stdout] http://mathematica.stackexchange.com/questions/74032/windows-command-line-arguments-stdin-stdout
Is it possible to utilize all three: commandline arguments, stdin, and stdout all at once in script for Windows? Unix is fairly esay, but I can’t get the following to work with Windows.
Using the ...
- asked by William (8 votes), answered by WReach (7 votes)
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[How can I replace the Greek symbols in an expression with their plain text names?]http://mathematica.stackexchange.com/questions/74047/how-can-i-replace-the-greek-symbols-in-an-expression-with-their-plain-text-names
Suppose I have an expression with Greek symbols in it. How would I convert that expression to another expression where the Greek symbols have been replaces with their names in plain text? I’ve ...
- asked by jmbejara (8 votes), answered by Mr.Wizard (11 votes)
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[Convert number to word]http://mathematica.stackexchange.com/questions/73717/convert-number-to-word
I have a big number like: 123 456 789. Now I’ll to writ it like this
123 million 456 thousand 789
I’ve search on the internet but nothing found that works.
How can you do that? Thanks.
- asked by Luis (8 votes), answered by Mr.Wizard (10 votes)
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[Why does an inert ReplaceAll modify this Dataset?]http://mathematica.stackexchange.com/questions/73855/why-does-an-inert-replaceall-modify-this-dataset
I cannot see any reason for this behavior besides a bug, but I’ve been wrong before so I put it before the community:
ds = Dataset[{ <|"ID" -> "Alpha", "v1" -> 1, "v2" -> 0|>, ...
- asked by Mr.Wizard (7 votes), answered by Leonid Shifrin (7 votes)
================================== Greatest hits from previous weeks: ==================================
[Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts]http://mathematica.stackexchange.com/questions/19546/image-processing-floor-plan-detecting-rooms-borders-area-and-room-names-t
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The ...
- asked by s.s.o (39 votes), answered by nikie (39 votes)
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[Generating visually pleasing circle packs]http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs
EDIT: (my conclusion and thank you note) I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you had fun and enjoyed it the same as I did.
I would like to ...
- asked by VividD (70 votes), answered by level1807 (42 votes)
================================== Can you answer these? ==================================
[Exclusion disappears but style doesn’t work]http://mathematica.stackexchange.com/questions/73894/exclusion-disappears-but-style-doesnt-work
Consider this code:
f[x_]:=(6 + 4 x + x^2 - x^3)/(x-2) Plot[f[x], {x, -10, 10}, Exclusions -> {2}, ExclusionsStyle -> Directive[Red, Dashed]]
It produces this image.
Note that the vertical ...
- asked by David (4 votes)
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[What is Association[Rule["ID",number ] and how it is used]http://mathematica.stackexchange.com/questions/74197/what-is-associationruleid-number-and-how-it-is-used
I am trying to understand the structure and the use of Dataset and I came across something new to me.
First check this example:
ds1=Dataset[{ <|"a" -> 1, "b" -> "x", "c" -> 6|>, ...
- asked by Algohi (4 votes)
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[Can I get a symbol cross-reference of a Mathematica Notebook?]http://mathematica.stackexchange.com/questions/73927/can-i-get-a-symbol-cross-reference-of-a-mathematica-notebook
Is there a way to get a cross reference listing for a notebook or set of notebooks?
- asked by Ralph Dratman (1 vote)
================================== Top new questions this week: ==================================
[Messages leak out from Block]http://mathematica.stackexchange.com/questions/73458/messages-leak-out-from-block
When assigning message to a symbol localized by Block, I would expect that this message is not accessible outside of Block, but I observe different behavior:
ClearAll[x] Block[x, x::test1 = ...
- asked by jkuczm (12 votes), answered by Mr.Wizard (6 votes)
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[Copy Built-in function to new name]http://mathematica.stackexchange.com/questions/73454/copy-built-in-function-to-new-name
It is know that some built-in functions are system function and changing their properties may cause trouble.
Suppose for example I want to change features of Cases:
SetAttributes[Cases, HoldFirst]
...
- asked by Algohi (10 votes), answered by Mr.Wizard (8 votes)
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[Possible bug: Quantity[2,"meters"] returns 2 None meters]http://mathematica.stackexchange.com/questions/73259/possible-bug-quantity2-meters-returns-2-none-meters
I’m using 10.0 for Linux.
Trial 1:
Quantity[2,"meters"] 2 None meters
Trial 2:
Quantity[2,"Meters"] 2 meters
Trial 3:
Quantity[2,"meters"] //InputForm Quantity[2*None, "Meters"]
It seems ...
- asked by Jacob Schwartz (10 votes)
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[How does $CellContext‘ work?] http://mathematica.stackexchange.com/questions/73530/how-does-cellcontext-work
The only official info about $CellContext‘ I was able to find is:
placeholder for the context of a symbol inside Dynamic
from StandardNamespaces
I have some intuitive understanding how it works ...
- asked by Kuba (9 votes), answered by Kuba (5 votes)
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[Solve a PDE over a region defined by a Bezier patch]http://mathematica.stackexchange.com/questions/73350/solve-a-pde-over-a-region-defined-by-a-bezier-patch
I am using NDSolve to find the solution to a PDE over an arbitrary domain. The domain is specified by a Bezier patch.
pts = 10, 0, 0, 30, 15, 10, 8, 30, 25, 37, 20, 37, 35, ...
- asked by cfdguy (9 votes), answered by Michael E2 (3 votes)
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[Triangular mesh of random points on a sphere] http://mathematica.stackexchange.com/questions/73354/triangular-mesh-of-random-points-on-a-sphere
My employer with a new logo (shown below). I do not have information on how this was created (as it was done by an outside company), though I’m fairly sure it was not done in any formal mathematical ...
- asked by user1375062 (9 votes), answered by ybeltukov (15 votes)
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[Slow work of SQLInsert with MS SQL Server in V10] http://mathematica.stackexchange.com/questions/73444/slow-work-of-sqlinsert-with-ms-sql-server-in-v10
This question is very similar to: Slow work of SQLInsert with SQLite, but for MS SQL Server. Unfortunately the use of SQLBeginTransaction and SQLCommitTransaction do not improved the performance as in ...
- asked by Murta (8 votes), answered by Murta (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to use Mathematica functions in Python programs?] http://mathematica.stackexchange.com/questions/4643/how-to-use-mathematica-functions-in-python-programs
I’d like to know how can I call Mathematica functions from Python.
I appreciate a example, for example, using the Mathematica function Prime.
I had search about MathLink but how to use it in Python ...
- asked by GarouDan (28 votes), answered by GarouDan (10 votes)
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[How do I clear all user defined symbols?] http://mathematica.stackexchange.com/questions/850/how-do-i-clear-all-user-defined-symbols
Is there some way to do this other than going to Evaluation -> Quit kernel and firing a new one up?
- asked by niklasfi (27 votes), answered by Artes (24 votes)
================================== Can you answer these? ==================================
[Problem with DiscretizeRegion] http://mathematica.stackexchange.com/questions/73470/problem-with-discretizeregion
R = RegionUnion[Disk[{0, 0}, 1, {0, Pi}], Disk[{1/2, 0}, 1/2]] // RegionDifference[#, RegionUnion[Disk[{1/2, 0}, 1/6], Disk[{-1/2, 0}, 1/2]]] & (dr = DiscretizeRegion[R]) // Timing
If you run ...
- asked by Apple (6 votes)
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[How to get the correct latitude and longitude coordinates using FindGeoLocation on street addresses] http://mathematica.stackexchange.com/questions/73656/how-to-get-the-correct-latitude-and-longitude-coordinates-using-findgeolocation
Have a list of street addresses:
addresses = {"123 D st, Davis, CA 95616", "140 B St, Davis, CA 95616", "212 E st, Davis, CA 95616", "325 G St, Davis, CA 95616"};
I used FindGeoLocation to ...
- asked by Rebecca (2 votes)
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[Why does Mathematica provide incosistent convergence conditions?]http://mathematica.stackexchange.com/questions/73652/why-does-mathematica-provide-incosistent-convergence-conditions
In[1]:= Clear[a, n] In[2]:= SumConvergence[(n^(n - 2))/((a^n)*(n!)), n] Out[2]= Abs[a] > E In[3]:= SumConvergence[(n^(n - 2))/((E^n)*(n!)), n] Out[3]= True
All right. So, according to Out[2], the ...
- asked by gaazkam (2 votes)
================================== Top new questions this week: ==================================
[Mathematica and POV-Ray workflow (Q&A)] http://mathematica.stackexchange.com/questions/72899/mathematica-and-pov-ray-workflow-qa
A couple of years ago, Alexey Popkov asked this question: Which ray tracing software is compatible with Graphics3D? It is my opinion, for various reasons, that out of the many ray tracing programs ...
- asked by Kim Fierens (18 votes), answered by xslittlegrass (17 votes)
—————————-
[Confused about how Partition works] http://mathematica.stackexchange.com/questions/72740/confused-about-how-partition-works
I have a problem about the padding list about Partition command. For instance,
Partition[a, b, c, d, e, f, g, 3, 1, -2, 1, x, y, z]
z, a, b, a, b, c, b, c, d, c, d, e, d, e, f, ...
- asked by ShutaoTang (16 votes), answered by Mr.Wizard (15 votes)
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[I define a variable as local to a module BUT then the module uses its global value! Why?] http://mathematica.stackexchange.com/questions/72758/i-define-a-variable-as-local-to-a-module-but-then-the-module-uses-its-global-val
I have a question about modules and local variables.
Here’s my example:
h = 5; Module[{a, h}, a[h_]= h^2; a[4]] (*Out[2] = 25*)
I expected the module to return 16 and not 25! I believed h to be ...
- asked by pan_e_gaban (12 votes), answered by Leonid Shifrin (13 votes)
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[Floating point operations division vs multiplication; how do they affect accuracy?] http://mathematica.stackexchange.com/questions/72801/floating-point-operations-division-vs-multiplication-how-do-they-affect-accur
Given two functions:
f[x_] := x ((x + 1)^(1/2) - x^(1/2)) g[x_] := x/((x + 1)^(1/2) + x^(1/2))
Which one is more accurate?
Side note: If you could explain why, that would really help me out, I ...
- asked by Claire Blackman (10 votes), answered by DumpsterDoofus (8 votes)
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[A better "VisibleSpectrum" function?] http://mathematica.stackexchange.com/questions/73161/a-better-visiblespectrum-function
Since ColorData["VisibleSpectrum"] is wrong I would like to have a more accurate function to use. Can this information be extracted from Mathematica itself?
- asked by Mr.Wizard (9 votes), answered by Mr.Wizard (10 votes)
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[Why can AppendTo modify a referenced list in-place but Part cannot?] http://mathematica.stackexchange.com/questions/72624/why-can-appendto-modify-a-referenced-list-in-place-but-part-cannot
Part, AppendTo, PrependTo, AddTo, etc. allow in-place modification of a list, but only Part requires that the list be referenced through a simple symbol, e.g. the following all does what you’ld ...
- asked by Eric Parker (9 votes), answered by Leonid Shifrin (11 votes)
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[Is there a way to identify a symbolic fraction?] http://mathematica.stackexchange.com/questions/73075/is-there-a-way-to-identify-a-symbolic-fraction
Is there a way to use Head to detect a symbolic fraction? In particular I find,
Head[a/b] Head[1/5]
Times
Rational
where I would like to get Head[a/b] = Rational. I want to test if a ...
- asked by JeffDror (8 votes), answered by ybeltukov (11 votes)
================================== Greatest hits from previous weeks: ==================================
[Division by zero is slow] http://mathematica.stackexchange.com/questions/64247/division-by-zero-is-slow
Suppose I have two arrays of data, which I want to divide:
n = 1000; a = RandomInteger[1, 9, n, n]; b = RandomInteger[1, 9, n, n]; First @ AbsoluteTiming @ (a/b)
0.637064
But suppose ...
- asked by wxffles (12 votes), answered by Michael E2 (6 votes)
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[Alternatives to procedural loops and iterating over lists in Mathematica]http://mathematica.stackexchange.com/questions/7924/alternatives-to-procedural-loops-and-iterating-over-lists-in-mathematica
While there are some cases where a For loop might be reasonable, it’s a general mantra one I subscribe to myself that "if you are using a For loop in Mathematica, you are probably doing it wrong". ...
- asked by Mr.Wizard (101 votes), answered by Mr.Wizard (66 votes)
================================== Can you answer these? ==================================
[Extra spaces when exporting strings into pdf (bug, linux)]http://mathematica.stackexchange.com/questions/72896/extra-spaces-when-exporting-strings-into-pdf-bug-linux
Rationale: Imagine you would like to create a publication quality figure in Mathematica, from under Linux. Naturally, it will contain text/labels.
Problem: Here is a simple string "Amin,new".
...
- asked by Alexey Bobrick (1 vote)
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[LayeredGraphPlot Vertex Spacing]http://mathematica.stackexchange.com/questions/72847/layeredgraphplot-vertex-spacing
For anyone who has used LayeredGraphPlot, you have probably seen that the vertex spacing is consistent throughout, that vertices have the same minimum unit of spacing in the vertical and horizontal ...
- asked by iwantmyphd (1 vote)
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[Header and footer banners in Slide Show style]http://mathematica.stackexchange.com/questions/72903/header-and-footer-banners-in-slide-show-style
I would like to create Mathematica slide shows that contain several tailored, fixed banners as headers and footers, much as MS Powerpoint, MS Word, Apple Pages, and LaTeX documents allow one to ...
- asked by David G. Stork (3 votes)
================================== Top new questions this week: ==================================
[Can Mathematica solve Plateau’s problem (finding a minimal surface with specified boundary)?] http://mathematica.stackexchange.com/questions/72203/can-mathematica-solve-plateaus-problem-finding-a-minimal-surface-with-specifie
Given a closed curve \(\mathcal C\) in three dimensions, is it possible to use Mathematica’s built-in functionality to compute a minimal surface whose boundary is \(\mathcal C\)? For simplicity, let us ...
- asked by Rahul (20 votes), answered by ybeltukov (17 votes)
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[Maximize[Cos[x - 1], x] is not evaluated] http://mathematica.stackexchange.com/questions/72444/maximizecosx-1-x-is-not-evaluated
No explanation needed:
Maximize[Cos[x + 1], x] Maximize[Cos[x - 1], x]
producing
{1, {x -> -1 + 2 Pi}}
Maximize[Cos[1 - x], x]
Needless to say, this is pretty amusing.
Does anyone know why ...
- asked by DumpsterDoofus (18 votes), answered by Michael E2 (8 votes)
—————————-
[Reading from a socket stream] http://mathematica.stackexchange.com/questions/72551/reading-from-a-socket-stream
I noticed an undocumented socket package (SocketLink) in Mathematica (Using version 10, not sure when it was actually added) and wrote a barebones HTTP responder using it:
<<SocketLink` host = ...
- asked by MBryn (10 votes)
—————————-
[For a given expression: if it appears, remove it, but if it is absent, add it] http://mathematica.stackexchange.com/questions/72380/for-a-given-expression-if-it-appears-remove-it-but-if-it-is-absent-add-it
While reformatting Szabolcs’s code from (42660) I noticed this interesting operation:
expr/.{{-\[Infinity],mid___,\[Infinity]}:>{mid},{-\[Infinity],mid___}:>{mid,\[Infinity]},{mid___,\[Infinity]}
- asked by Mr.Wizard (10 votes), answered by Mr.Wizard (5 votes)
—————————-
[Unexpected pattern matching behaviour: PatternSequence vs. Optional]http://mathematica.stackexchange.com/questions/72290/unexpected-pattern-matching-behaviour-patternsequence-vs-optional
Consider the following pattern-matching expressions:
MatchQ[{1, 2}, {a_, b_}] (* True *) MatchQ[{1, 2}, {a_, b_:0}] (* True *) MatchQ[{1, 2}, ...
- asked by WReach (10 votes)
—————————-
[Incorrect use of Scaled causes crash]http://mathematica.stackexchange.com/questions/72560/incorrect-use-of-scaled-causes-crash
Bug introduced in 8.0 and persisting through 10.0.2 or later
While playing with Scaled, I made a syntax error which caused a crash instead of an error message ...
Do you get the same ? (I have ...
- asked by SquareOne (9 votes)
—————————-
[Using map projections with astronomical data]http://mathematica.stackexchange.com/questions/72426/using-map-projections-with-astronomical-data
I noticed that all important "Geoprojections" are available in projections for a spherical reference models: GeoProjectionData function;
1 - I am trying using the sinusoidal projection for ...
- asked by locometro (8 votes), answered by Kuba (7 votes)
================================== Greatest hits from previous weeks: ==================================
[How to find all the local minima/maxima in a range]http://mathematica.stackexchange.com/questions/5575/how-to-find-all-the-local-minima-maxima-in-a-range
I want to find :
all local maxima in range all local minima in range
>From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ...
- asked by Margus (46 votes), answered by Daniel Lichtblau (45 votes)
—————————-
[Alternatives to procedural loops and iterating over lists in Mathematica]http://mathematica.stackexchange.com/questions/7924/alternatives-to-procedural-loops-and-iterating-over-lists-in-mathematica
While there are some cases where a For loop might be reasonable, it’s a general mantra one I subscribe to myself that "if you are using a For loop in Mathematica, you are probably doing it wrong". ...
- asked by Mr.Wizard (101 votes), answered by Mr.Wizard (66 votes)
================================== Can you answer these? ==================================
[Is there a notebook to create entries for OEIS?]http://mathematica.stackexchange.com/questions/72451/is-there-a-notebook-to-create-entries-for-oeis
Is there a notebook to create entries for OEIS?
I seem to recall something like this a few years ago, but I haven’t been able to find one. It might be from MathWorld. Any suggestions?
Edit If I had ...
- asked by Fred Kline (2 votes)
—————————-
[SumConvergence fails in version 10] http://mathematica.stackexchange.com/questions/72361/sumconvergence-fails-in-version-10
SumConvergence[(-1)^(n + 1) ((Cos[n^2] + Sin[n + 2])/7^n), n]
Mathematica fails to provide a result (true/false) but wolfram alpha works. What should I do ?
It gives ...
- asked by Parhs (5 votes)
—————————-
[How can I detect certain letters by shape in an image?] http://mathematica.stackexchange.com/questions/72497/how-can-i-detect-certain-letters-by-shape-in-an-image
I have a website where people can post Flipbook animations, called Flipnotes. Unfortunately, most of the Popular flipnotes are in the following categories:
MV (Music Video) AV (Audio Video) AMV ...
- asked by Austin Burk (1 vote)
================================== Top new questions this week: ==================================
[Excessive memory use by Mathematica kernel in 10.0.2 after executing simple commands] http://mathematica.stackexchange.com/questions/71889/excessive-memory-use-by-mathematica-kernel-in-10-0-2-after-executing-simple-comm
Warning: the code below may hang your system if you have the Suggestions Bar enabled.
When issuing the following simple statements to Mathematica, it responds with a valid answer. However, ...
- asked by Simon (18 votes), answered by Simon (8 votes)
—————————-
[What is the purpose of Internal‘LocalizedBlock?]http://mathematica.stackexchange.com/questions/71881/what-is-the-purpose-of-internallocalizedblock
I have come across the (internal) use of of the function:
Internal‘LocalizedBlock
I am trying to determine its purpose. It seem to behave like Internal‘InheritedBlock except that a starting value ...
- asked by Mr.Wizard (14 votes), answered by Dan Fortunato (19 votes)
—————————-
[Least effort to handle a point source inside the domain of PDE(s)]http://mathematica.stackexchange.com/questions/71902/least-effort-to-handle-a-point-source-inside-the-domain-of-pdes
By point source I mean a constrained condition at one point inside the domain of PDE(s). For example:
$$\frac{\partial ^2u(t,x,y)}{\partial t^2}=\frac{\partial ^2u(t,x,y)}{\partial ...
- asked by xzczd (13 votes), answered by Rahul (10 votes)
—————————-
[Partitioning with constraints on subsets]http://mathematica.stackexchange.com/questions/71827/partitioning-with-constraints-on-subsets
Given the following data:
constraints = 11, 2, 11, 3, 11, 4, 11, 6, 11, 9, 1, 6, 5, 6, 2, 5;
weights = 3, 7, 3, 2, 4, 2, 2, 2, 3, 2, 1;
I wish to partition the integers from 1 ...
- asked by Simon Woods (13 votes), answered by ybeltukov (6 votes)
—————————-
[Filling to Axis as Arrow]http://mathematica.stackexchange.com/questions/72002/filling-to-axis-as-arrow
In version 9 I could do the following with the output as shown.
ListPlot[Table[{x, x^2}, {x, 0, 1, 0.1}], PlotRange -> All, Filling -> Axis, FillingStyle -> (Arrow[#] &)]
Now in ...
- asked by Hugh (11 votes), answered by Mr.Wizard (9 votes)
—————————-
[Label multiple edges between same vertices]http://mathematica.stackexchange.com/questions/72003/label-multiple-edges-between-same-vertices
I have a simple graph with multiple edges between two vertices, say:
Graph[{ Labeled[a -> b, "A"], Labeled[a -> b, "B"] }]
Unfortunately, Mathematica labels both edges "A".
How can I ...
- asked by Thomas Fankhauser (9 votes), answered by kguler (6 votes)
—————————-
[Synchronizing the camera view of multiple Image3D panels within a Manipulate interface]http://mathematica.stackexchange.com/questions/71653/synchronizing-the-camera-view-of-multiple-image3d-panels-within-a-manipulate-int
I’m trying to synchronize the camera view of multiple Image3D panels displayed within a Manipulate interface.
A random 3D image will do for demonstration purposes.
theimg = Image3D[RandomReal[1, ...
- asked by Matt (9 votes), answered by bobthechemist (8 votes)
================================== Greatest hits from previous weeks: ==================================
[How to use Mathematica functions in Python programs?]http://mathematica.stackexchange.com/questions/4643/how-to-use-mathematica-functions-in-python-programs
I’d like to know how can I call Mathematica functions from Python.
I appreciate a example, for example, using the Mathematica function Prime.
I had search about MathLink but how to use it in Python ...
- asked by GarouDan (27 votes), answered by GarouDan (10 votes)
—————————-
[How to make use of Associations?]http://mathematica.stackexchange.com/questions/52393/how-to-make-use-of-associations
I have been curious about it for long. Now that Mathematica 10 arrives, I think it’s time to ask the question: How the new Association data structure would be used to improve Mathematica programming?
...
- asked by Yi Wang (67 votes), answered by Leonid Shifrin (70 votes)
================================== Can you answer these? ==================================
[How to rewrite a nested loop with Reap and Sow]http://mathematica.stackexchange.com/questions/71838/how-to-rewrite-a-nested-loop-with-reap-and-sow
I was wondering if anyone know how to rewrite the following nested loop but using Reap and Sow. I need to reduce the execution time. Thank you.
list = ; AbsoluteTiming[ Do[ AppendTo[list, ]; ...
- asked by Paul (1 vote)
—————————-
[PlotRange->Automatic the exact function used to calculate outliers]http://mathematica.stackexchange.com/questions/71808/plotrange-automatic-the-exact-function-used-to-calculate-outliers
I know that PlotRange->Automatic does the following:
"the distribution of coordinate values is found, and any points sufficiently far out in the distribution are dropped. Such points are often ...
- asked by Nick (2 votes)
—————————-
[How to reduce a quartic form to a quadratic form with equal roots]http://mathematica.stackexchange.com/questions/72083/how-to-reduce-a-quartic-form-to-a-quadratic-form-with-equal-roots
Preface: To clear the theoretical background this question is cross-posted on math.stackexchange here.
I have a polynomial in \(n\) variables of the form
...
- asked by E.O. (3 votes)
================================== Top new questions this week: ==================================
[Why is my data 10 times slower than random data when doing matrix multiplication] http://mathematica.stackexchange.com/questions/71377/why-is-my-data-10-times-slower-than-random-data-when-doing-matrix-multiplication
I have some data generated from some program, and it appears that matrix multiplication on these data are about 10 times slower than on some random data:
Get["tb.dat"];
xls = Range[-500, 500, ...
- asked by xslittlegrass (14 votes), answered by DumpsterDoofus (10 votes)
—————————-
[What happens when you divide by ##
?]
http://mathematica.stackexchange.com/questions/71348/what-happens-when-you-divide-by
I’ve been playing around with sequences a bit. In particular with using ##
with unary and
binary operators.
Let’s start simple, the following all make some kind of sense:
+ ## & [a,b] (* a + b ...
- asked by Martin Buttner (13 votes), answered by Pickett (11 votes)
—————————-
[How can FactorInteger be so slow if PrimeQ is fast?] http://mathematica.stackexchange.com/questions/71489/how-can-factorinteger-be-so-slow-if-primeq-is-fast
My 8th grade son had a homework problem to find a prime factor of 99!-1. I thought to be clever/lazy and used FactorInteger[99!-1], but it takes forever. PrimeQ[99!-1] very quickly gives False. It ...
- asked by Martin Rommel (11 votes), answered by sn6uv (16 votes)
—————————-
[Orderless pattern matching] http://mathematica.stackexchange.com/questions/71463/orderless-pattern-matching
The MMA docs state that "In matching patterns with Orderless functions, all possible orders of arguments are tried".
Why then does the following not work?
plus[x__Integer, y__Real] := x+y ...
- asked by sn6uv (9 votes), answered by Mr.Wizard (11 votes)
—————————-
[Why is this evaluation halved when adding units?] http://mathematica.stackexchange.com/questions/71496/why-is-this-evaluation-halved-when-adding-units
Why does this strange behavior occur when dealing with units and quantities?
A[t_] := A0 Exp[-b t / (2m)] FullSimplify[A[Quantity[0, "Seconds"]]]
A0 – ...
- asked by WChargin (8 votes)
—————————-
[Multiple bwspec for BoxWhiskerChart] http://mathematica.stackexchange.com/questions/71478/multiple-bwspec-for-boxwhiskerchart
If I want to make a horizontal boxplot (with outliers) for y:
y = {5.5, 5.61, 4.88, 5.07, 5.42, 5.55, 5.36, 5.29, 5.58, 5.65, 5.57, 5.53, 5.62, 5.29, 5.44, 5.34, 5.79, 5.1, 5.27, 5.39, 5.42, 5.47, ...
- asked by shidangai (7 votes), answered by m_goldberg (6 votes)
—————————-
[The longest run of at most k different elements in a list] http://mathematica.stackexchange.com/questions/71587/the-longest-run-of-at-most-k-different-elements-in-a-list
I have a long list with ca. 500K elements. The list contains about 10K different elements.
For simplicity lets assume the list is of the following form:
list={a,c,b,a,a,a,b,c,e,f,b,a,e,e,e,a}
I ...
- asked by stat_facts (6 votes), answered by Mr.Wizard (5 votes)
================================== Greatest hits from previous weeks: ==================================
[What are the most common pitfalls awaiting new users?] http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by belisarius (188 votes), answered by Michael E2 (101 votes)
—————————-
[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (17 votes), answered by Artes (10 votes)
================================== Can you answer these? ==================================
[Extracting an equation from an interpolated function] http://mathematica.stackexchange.com/questions/71595/extracting-an-equation-from-an-interpolated-function
Im trying to use LibraryLink to do some calculations in C but part of the expression i want to calculate is an Interpolating Function. C cant use that obviously so I’m trying to shift it to a data ...
- asked by Nicholas Gaffney-Henderson (3 votes)
—————————-
[Input `Reduce[Mod[a + x, l] == 0, x]' and output `x == -a + kl`
?]
http://mathematica.stackexchange.com/questions/71365/input-reducemoda-x-l-0-x-and-output-x-a-kl
Reduce[a + x == k l && k > 0, x] (* k > 0 && x == -a + k l *) I think a + x == k l and Mod[a + x, l] == 0 are equivalent, but when I replace a + x == k l by Mod, Mathematica ...
- asked by LoveRight (1 vote)
—————————-
[ListPlot3D keeps crashing] http://mathematica.stackexchange.com/questions/71559/listplot3d-keeps-crashing
I have some data, and I want to plot it by ListPlot3D:
image1 = Import["image1.dat", "TSV"]; image1 // Dimensions (* -> {150000, 3} *) I used: ListPlot3D[image1[[1 ;; 50000]], MaxPlotPoints ...
- asked by yashar (1 vote)
================================== Top new questions this week: ==================================
[Generating 250 random points crashes the kernel, but not 249] http://mathematica.stackexchange.com/questions/69891/generating-250-random-points-crashes-the-kernel-but-not-249
Consider the following function, which generates uniformly random points on the surface of the 2-sphere:
randSphere[] := Block[{z = RandomReal[{-1, 1}, 3]}, If[Total[z^2] > 1, randSphere[], ...
- asked by David Zhang (23 votes), answered by Szabolcs (22 votes)
—————————-
[How to add lines in TableForm] http://mathematica.stackexchange.com/questions/69970/how-to-add-lines-in-tableform
m = { {3, 5, 5, 5, 5, 5, 5, 5}, {3, 6, 8, 8, 8, 8, 8, 8}, {3, 6, 10, 11, 11, 11, 11, 11}, {3, 6, 10, 14, 14, 14, 14, 14}, {3, 6, 10, 15, 17, 17, 17, 17}, {3, 6, 10, 15, ...
- asked by Chen Stats Yu (17 votes), answered by kguler (10 votes)
—————————-
[Gap in a continuous plot] http://mathematica.stackexchange.com/questions/69976/gap-in-a-continuous-plot
Why do I get a gap in the plot below and how can I fix it? (If you are interested in it, you can see a new related question: How to plot an implicit value funtion, which is also a little chanlenging)
...
- asked by ben (13 votes), answered by kguler (9 votes)
—————————-
[Max element of a list with a custom ordering function] http://mathematica.stackexchange.com/questions/69971/max-element-of-a-list-with-a-custom-ordering-function
I need a function to find max element of a list according to some custom ordering function, assuming that the function implements a total order (elements being compared might not even be numbers). ...
- asked by Vladimir Reshetnikov (10 votes), answered by Mr.Wizard (8 votes)
—————————-
[Choose between ‘Apply‘ and ‘Map‘] http://mathematica.stackexchange.com/questions/70201/choose-between-apply-and-map
Even though this might be too general question(or not answerable), I want to get some advice here. I apologize in advance if it is not a relevant question.
I frequently have to process large list of ...
- asked by Sungmin (8 votes)
—————————-
[Collatz optimization] http://mathematica.stackexchange.com/questions/69902/collatz-optimization
I’m VERY new to Mathematica programming (and by new I mean two days), and was solving Project Euler question 12, which states:
Which starting number, under one million, produces the longest ...
- asked by globby (8 votes), answered by mgamer (9 votes)
—————————-
[How to connect discrete points and make them become continuous curve?] http://mathematica.stackexchange.com/questions/70102/how-to-connect-discrete-points-and-make-them-become-continuous-curve
Given that I have two variables \(\theta ,t\), for the varible \(t\), \(\theta \) always owns several values. Namely, \[\{t,\theta _1,\theta _2,\theta _3,\theta _4...\}\] where \(t\) in the interval\([0,1]\) and ...
- asked by ShutaoTang (7 votes), answered by Yi Wang (12 votes)
================================== Greatest hits from previous weeks: ==================================
[Image processing: Floor plan - detecting rooms’ borders (area) and room names’ texts] http://mathematica.stackexchange.com/questions/19546/image-processing-floor-plan-detecting-rooms-borders-area-and-room-names-t
Here is a simple building floor plan. I would like to derive the rooms as (rectangular) components and the names of the rooms. This is very common representation of building floor plans.
The ...
- asked by s.s.o (37 votes), answered by nikie (38 votes)
—————————-
[1 Plot, 2 Scale/Axis] http://mathematica.stackexchange.com/questions/627/1-plot-2-scale-axis
I would like to plot those two datasets on top of each other. But they have very different range on the \(y\) axis. How can I have two different axis?
I found the following on the help menu but quite ...
- asked by 500 (77 votes), answered by ArgentoSapiens (70 votes)
================================== Can you answer these? ==================================
[How to control pedestrians to enter the simulation region with random functions?] http://mathematica.stackexchange.com/questions/70173/how-to-control-pedestrians-to-enter-the-simulation-region-with-random-functions
I am working on simulating crowds of a cross-typed region, given that pedestrians entering from 4 gates of north, east, west and south,
spacesize = 100;width = Floor[0.1 spacesize]; npeople = ...
- asked by Andy Huang (2 votes)
—————————-
[Why does Mathematica show 4095/4096 terms in TrigExpand?] http://mathematica.stackexchange.com/questions/70092/why-does-mathematica-show-4095-4096-terms-in-trigexpand
Clear[x, n]; expr = Cos[x]^(n - 2) (1 - Cos[x]^2 + Sin[x]); r=TrigExpand[expr]
Where do those 4095/4096 comes from? It is correct, but it seems very strange way to represent the result.
...
- asked by Nasser (3 votes)
—————————-
[How to get the SIFT features of an image?] http://mathematica.stackexchange.com/questions/70165/how-to-get-the-sift-features-of-an-image
According to the documentation, the function KeyPoints[] computes features only using SURF, but what about SIFT or FAST features?
- asked by M.R. (1 vote)
================================== Top new questions this week: ==================================
[How would I return a random Mathematicacommand?] http://mathematica.stackexchange.com/questions/69627/how-would-i-return-a-random-mathematica-command
I’m doing some metaprogramming. How would I make a Mathematica function that returns a random Mathematica command? Is there a list of command names that I could use RandomChoice on?
I’m looking for ...
- asked by Alexander Gruber (10 votes), answered by bill s (16 votes)
—————————- [Rendering thousands ofpoints] http://mathematica.stackexchange.com/questions/69774/rendering-thousands-of-points
I am trying to render an image with some 120,000 Points. Technically it’s just 10,000 points, plus their reflection, plus 5 rotations of both of those sets, but I’m not sure that’s relevant. The code ...
- asked by Martin Buttner (9 votes), answered by Sjoerd C. de Vries (11 votes)
—————————-
[Truncating a list once all members of a set have appeared?] http://mathematica.stackexchange.com/questions/69613/truncating-a-list-once-all-members-of-a-set-have-appeared
Consider if you would the case where we have some list of elements:
list0 = 54, 4, 7, 9, 3, 54, 4, 20, 2, 456, 2, 3;
And we have some target list:
targetList = 2, 3, 4, 7;
We’d like to scan ...
- asked by GreenField (9 votes), answered by Mr.Wizard (4 votes)
—————————-
[Find the minimum integer r such that \((10^r - 1)/37\) is an integer] http://mathematica.stackexchange.com/questions/69811/find-the-minimum-integer-r-such-that-10r-1-37-is-an-integer
I know Element[(10^r - 1)/37, Integers] tests the condition.
So what is the command that gives me the minimum integer value r such that the condition is true?
- asked by LoveRight (7 votes), answered by Oleksandr R. (10 votes)
—————————-
[Definite integral incorrectly giving a nonreal value] http://mathematica.stackexchange.com/questions/69718/definite-integral-incorrectly-giving-a-nonreal-value
In Mathematica 10.0, when I enter
N[Integrate[Sqrt[1+x^3],{x,-1,3}]] , I get a nonreal value. (I.e., the imaginary part is nonzero.) Why? This arose when I was seeing if Sqrt[1_x^3] has an ...
- asked by Stephen Herschkorn (7 votes), answered by Nasser (6 votes)
—————————-
[LetterCharacter for Cyrillic symbols]http://mathematica.stackexchange.com/questions/69728/lettercharacter-for-cyrillic-symbols
Why does the code
StringMatchQ["bl", LetterCharacter]
return False?
Probably because:
StringMatchQ[bl", LetterCharacter] // HoldForm // FullForm ...
- asked by molekyla777 (7 votes), answered by Karsten 7. (7 votes)
—————————-
[How discretize a region placing vertices on a specific non-uniform grid] http://mathematica.stackexchange.com/questions/69584/how-discretize-a-region-placing-vertices-on-a-specific-non-uniform-grid
Given a generic region, for example:
\[CapitalOmega] = ImplicitRegion[((2*x^2 + 3*y^2 + 2*x*y - 2 & )*lt; ) = (0^x^2 + y^2 & )*gt; 0.1, {x, y}]; and a non-uniform grid, for example: \[CapitalOmega]b = RegionBounds[\[CapitalOmega]]; {xg, yg} = ...
- asked by unlikely (6 votes), answered by kguler (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (17 votes), answered by Artes (10 votes)
—————————-
[What are the most common pitfalls awaiting new users?] http://mathematica.stackexchange.com/questions/18393/what-are-the-most-common-pitfalls-awaiting-new-users
As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ...
- asked by belisarius (184 votes), answered by Michael E2 (99 votes)
================================== Can you answer these? ==================================
[DSolve versus DSolveValue] http://mathematica.stackexchange.com/questions/69793/dsolve-versus-dsolvevalue
I’ve just discovered the new command DSolveValue in Mathematica 10. Is this new command now the preferred instead of DSolve? Is it the better command to teach to students? Same question for ...
- asked by David (2 votes)
—————————-
[Font rendering difference between .jpg & .pdf] http://mathematica.stackexchange.com/questions/69825/font-rendering-difference-between-jpg-pdf
I have some planar graphics involving lines and text, produced by Line[] and Text[], accepting the default font on the latter. When I Save Graphics as .jpg, it looks fine, left below. When I save as ...
- asked by Joseph O’Rourke (2 votes)
—————————-
[Regular Polyhedra coordinate points generation] http://mathematica.stackexchange.com/questions/69839/regular-polyhedra-coordinate-points-generation
Is it possible to get all points on a Polyhedron surface using two surface parameters, say
\( \phi ,\theta \) spherical co-ordinates?
Just like in ParametricPlot3D, can we start with PolyhedronData ...
- asked by Narasimham (1 vote)
================================== Top new questions this week: ==================================
[Buying a new computer (specifically for Mathematica)] http://mathematica.stackexchange.com/questions/69404/buying-a-new-computer-specifically-for-mathematica
My current computer is a MacBook Air, the mid-2011 version: 4 GB RAM, 1.7 GHz Intel dual core. It runs Mathematica 9 smoothly, but a bit too slowly for my taste. I use Mathematica almost exclusively ...
- asked by Kim Fierens (14 votes), answered by halirutan (15 votes)
—————————-
[Difference between Association and Dispatch] http://mathematica.stackexchange.com/questions/69291/difference-between-association-and-dispatch
In the example below, Association has a different behavior from Dispatch:
{1, 2, 3} /. Association@{1 -> "test",2 -> "test" , _Integer -> Null} {1, 2, 3} /. Dispatch@{1 -> "test" ,2 -> ...
- asked by Murta (13 votes), answered by Leonid Shifrin (15 votes)
—————————-
[Real Numbers in the Wolfram Language] http://mathematica.stackexchange.com/questions/69525/real-numbers-in-the-wolfram-language
This is more of a request for advice and input than a solution to a programming challenge, but I thought it might be useful to raise here nonetheless.
I am wondering if Mathematica and the Wolfram ...
- asked by David Carraher (11 votes)
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[InverseFourierTransform of simple function takes forever] http://mathematica.stackexchange.com/questions/69477/inversefouriertransform-of-simple-function-takes-forever
i’m quite new to Mathematica. I’m trying to do something along the lines of:
InverseFourierTransform[1/(w^2 - I*w*b + c) , w, t, FourierParameters -> {1, -1}, Assumptions -> {b > 0, c > ...
- asked by pnjun (9 votes), answered by bbgodfrey (8 votes)
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[Divide all but the maximal element in a list by 10?] http://mathematica.stackexchange.com/questions/69547/divide-all-but-the-maximal-element-in-a-list-by-10
I have a list of numerical data, and I want to write a program that will keep the maximum as it is, but reduce the rest by certain factor (such as 10). For example:
input = {2, 3, 1, -3, -5, 9, 2, 6, ...
- asked by Paul (8 votes), answered by WReach (10 votes)
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[Select a particular rules out of a list] http://mathematica.stackexchange.com/questions/69299/select-a-particular-rules-out-of-a-list
rule = {beta -> 4, alpha -> 2, x -> 4, z -> 2, w -> 0.8} Select[rule, beta] Select[rule, beta &] Select[rule, beta -> _ &]
How would I select the rule that applies to beta ...
- asked by Chen Stats Yu (8 votes), answered by kguler (12 votes)
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[10.0.2 another Dataset type system (inference?) warning] http://mathematica.stackexchange.com/questions/69542/10-0-2-another-dataset-type-system-inference-warning
Bug introduced in 10.0.2
The warning below seems unrelated to these issues: Did 10.0.2 break some forms for named slots? and 10.0.2 mapping Association to Dataset warning.
First noticed w/ ...
- asked by alancalvitti (7 votes), answered by Stefan R (11 votes)
================================== Greatest hits from previous weeks: ==================================
[How to find all the local minima/maxima in a range] http://mathematica.stackexchange.com/questions/5575/how-to-find-all-the-local-minima-maxima-in-a-range
I want to find :
all local maxima in range all local minima in range
>From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ...
- asked by Margus (45 votes), answered by Daniel Lichtblau (43 votes)
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[How to create animated snowfall?] http://mathematica.stackexchange.com/questions/16881/how-to-create-animated-snowfall
Well, the title is self-explanatory. What sorts of snowfall can we generate using Mathematica? There are two options I suggest to consider:
1) Continuous GIF animations with smallest possible number ...
- asked by faleichik (30 votes), answered by Simon Woods (35 votes)
================================== Can you answer these? ==================================
[How to execute code on FrontEnd quit?] http://mathematica.stackexchange.com/questions/69385/how-to-execute-code-on-frontend-quit
I would like to execute a block of code whenever the FrontEnd quits. I know about $Epilog, but it seems that this would execute every time the kernel quits, which is not what I want. Does anyone know ...
- asked by rdjain1 (4 votes)
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[Logarithmic vertex placement in large tree graphs] http://mathematica.stackexchange.com/questions/69555/logarithmic-vertex-placement-in-large-tree-graphs
This question about graph layout is fairly general, but can be illustrated in the case of the Collatz Conjecture. Collatz created the following function over positive integers: If the integer n is ...
- asked by David G. Stork (1 vote)
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[Background color does not display in InputField unless Appearance option is also specified] http://mathematica.stackexchange.com/questions/69446/background-color-does-not-display-in-inputfield-unless-appearance-option-is-also
I get the same behavior for v.10.0.2 and v.9 with OS X (10.9.5) :
No background color is displayed in InputField if I just set properly the option. For example, the background just remains white if ...
- asked by SquareOne (2 votes)
================================== Top new questions this week: ==================================
[Bug in ArcLength?]http://mathematica.stackexchange.com/questions/69122/bug-in-arclength
With Mathematica 10.0.2:
ArcLength[Line[{{0, 0}, {1, 0}, {2, 0}}]] ArcLength[Line[{{0}, {1}, {2}}]] (* 2 *) (* 2 *) However, ArcLength[Line[{{0, 0}, {1, 0}, {2.0, 0}}]] ArcLength[Line[{{0}, {1}, ...
- asked by qwerty (15 votes)
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[Save as pdf broken in version 10.0.2?] http://mathematica.stackexchange.com/questions/68893/save-as-pdf-broken-in-version-10-0-2
It looks like the save as pdf is broken after I update to version 10.0.2. The labels in the plot become a mess.
Are there ways to fix it? The Export function works well though.
Here is a screenshot
...
- asked by xslittlegrass (12 votes)
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[What does f_[whoCalled]^:=f
really mean?]
http://mathematica.stackexchange.com/questions/68823/what-does-f-whocalled-f-really-mean
I came across the following post by John Doty in this Google Groups discussion:
On Friday, January 11, 2013 8:23:16 PM UTC-7, amzoti wrote:
It is clear the Mathematica uses Lisp as one ...
- asked by Shredderroy (11 votes), answered by Chris Degnen (1 vote)
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[10.0.2 mapping Association to Dataset warning] http://mathematica.stackexchange.com/questions/68875/10-0-2-mapping-association-to-dataset-warning
In 10.0.2
ExampleData[{"Dataset", "Titanic"}][All, <| "gender" -> #sex|> &] Outputs the expected result, but also throws: MapAt::partw: Part {1,All,2} of ...
- asked by alancalvitti (10 votes), answered by Taliesin Beynon (12 votes)
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[Sampling phase space uniformly for a given energy] http://mathematica.stackexchange.com/questions/69029/sampling-phase-space-uniformly-for-a-given-energy
For example, for the 1D harmonic oscillator, the energy is given by: \[ E = \frac {1}{2 m} p^2 + \frac {m \omega ^2}{2} x^2 \] where x is position and p is the momentum.
I would like to sample phase ...
- asked by user29165 (8 votes), answered by bbgodfrey (5 votes)
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[representation of custom deformation on a meshgrid] http://mathematica.stackexchange.com/questions/69132/representation-of-custom-deformation-on-a-meshgrid
I am trying to represent 2D deformations on a rectangular grid. In Mathematica 10, there is a method to solve the elastic differential equations and then represent the deformation as presented here:
...
- asked by Botond (7 votes), answered by Michael E2 (9 votes)
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[Processing a circular rainbow in an image] http://mathematica.stackexchange.com/questions/69092/processing-a-circular-rainbow-in-an-image
I was flying cross country last week. We were at about 35000 feet with a complete cloud deck below us. I looked down and saw a complete circular rainbow above the clouds. It was in view about 10 ...
- asked by Rob (7 votes), answered by bill s (9 votes)
================================== Greatest hits from previous weeks: ==================================
[How to find the domain and range of a function with Mathematica?] http://mathematica.stackexchange.com/questions/8016/how-to-find-the-domain-and-range-of-a-function-with-mathematica
I’m studying calculus and in some exercises I am asked to find the domain and range of a function. Does Mathematica have already a built-in function for this?
I can imagine some ways of doing so, ...
- asked by Vyska (17 votes), answered by Szabolcs (18 votes)
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[How to ask Mathematica to imitate Andy Warhol’s pop-art painting?] http://mathematica.stackexchange.com/questions/59132/how-to-ask-mathematica-to-imitate-andy-warhols-pop-art-painting
I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe’s portrait so that it looks like Warhol’s world famous pop-art painting. However, the result shown below is far from ...
- asked by Putterboy (37 votes), answered by belisarius (41 votes)
================================== Can you answer these? ==================================
[Linux: Mathematica crashes when clicking documentation links very fast] http://mathematica.stackexchange.com/questions/68927/linux-mathematica-crashes-when-clicking-documentation-links-very-fast
Can someone confirm the following behavior: Open a new Mathematica and go to the documentation. Navigate to any reference page (I used RegionPlot) and click repeatedly and very fast the RegionPlot ...
- asked by halirutan (5 votes)
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[Import/Export a FIT file, Fitness file created by Garmin GPS’s and others] http://mathematica.stackexchange.com/questions/69085/import-export-a-fit-file-fitness-file-created-by-garmin-gpss-and-others
A FIT file is a binary replacement for GPX and TCX text files containing GPS and fitness data (heart monitors, etc.). Mathematica reads GPX and TCX files and represents them as XML. I would like to ...
- asked by Douglas Kubler (1 vote)
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[Creating REST Web Service with webMathematica] http://mathematica.stackexchange.com/questions/69021/creating-rest-web-service-with-webmathematica
Someone knows how can I implement a REST Web Service with webMathematica?
The SOAP service is well documented here and in the webMathematica User Guide.
I saw that is possible to create a REST ...
- asked by Murta (4 votes)
================================== Top new questions this week: ==================================
[Where is the old option TraceInternal->True?] http://mathematica.stackexchange.com/questions/67305/where-is-the-old-option-traceinternal-true
Already at least in version 2 (I think), the function Solve calls the function Roots. At that time, I had a rather dirty trick, that still works, to verify this:
Unprotect[Roots]; Roots[x___] /; ...
- asked by Fred Simons (14 votes), answered by WReach (13 votes)
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[What are the purposes of functions in FrontEnd‘ context which are duplicates of those in System‘?] http://mathematica.stackexchange.com/questions/67179/what-are-the-purposes-of-functions-in-frontend-context-which-are-duplicates-of
I noticed that for notebook-related heads, there are usually a pair of same functions, one in System context, another in FrontEnd context. I filtered out a list of functions of this kind:
candidates ...
- asked by Naitree (9 votes), answered by Naitree (6 votes)
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[Modify existing color scheme] http://mathematica.stackexchange.com/questions/67212/modify-existing-color-scheme
I am using the "TemperatureMap" color scheme for image processing. How can I set the lowest color value to Black?
Generally speaking, is it possible to exchange a specific color (at a certain value ...
- asked by Milenko Rubin-Zuzic (8 votes), answered by rm -rf (13 votes)
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[Get rational and irrational parts] http://mathematica.stackexchange.com/questions/67293/get-rational-and-irrational-parts
Consider an expression of the form \(a + b \sqrt {2}\), where \(a,b \in \mathbb {Q}\). How can I extract \(b\) (or equivalently \(a\)) from this expression?
- asked by Tyson Williams (8 votes), answered by Michael E2 (6 votes)
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[Implementation of Partial Least Squares (PLS)?] http://mathematica.stackexchange.com/questions/67282/implementation-of-partial-least-squares-pls
I’m looking for a PLS implementation for Wolfram Mathematica. I just cant seem to find any implementation for it - do you know one? In general, I’m a bit confused that there exist only so few ...
- asked by tim (6 votes)
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[A short notation to fix the assumption that all involved parameters are, say, positive] http://mathematica.stackexchange.com/questions/67601/a-short-notation-to-fix-the-assumption-that-all-involved-parameters-are-say-po
Often I make simplifications or other operations with assumptions. Sometimes the assumptions simply state that all parameters involved are positive.
I wonder, if there is a short notation for such a ...
- asked by Alexei Boulbitch (5 votes), answered by kguler (2 votes)
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[Why are TimeSeries objects reported with head "TemporalData"?] http://mathematica.stackexchange.com/questions/67597/why-are-timeseries-objects-reported-with-head-temporaldata
I am quite surprised to find that
ts = TimeSeries[ {1,2,3,4}, {{1,2,3,4}}]; Head @ ts returns (* TemporalData *)
I do find this quite inconsistent as the object is also reported with ...
- asked by gwr (5 votes)
================================== Greatest hits from previous weeks: ==================================
[Even Fibonacci numbers] http://mathematica.stackexchange.com/questions/37266/even-fibonacci-numbers
Today, I found the Euler Project. Problem #2 is
Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be:
1, ...
- asked by ShutaoTang (24 votes), answered by rcollyer (31 votes)
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[Implementing efficient multiple undo] http://mathematica.stackexchange.com/questions/1953/implementing-efficient-multiple-undo
At the time this question was asked, version 10 was not out yet. The Front End of Mathematica 10 does have multiple undo, see the answer by John Fultz.
The Mathematica Front End’s built-in Undo ...
- asked by Rojo (112 votes), answered by John Fultz (38 votes)
================================== Can you answer these? ==================================
[The CorrelationMatrix is equal to corrcoef of Matlab?] http://mathematica.stackexchange.com/questions/67348/the-correlationmatrix-is-equal-to-corrcoef-of-matlab
I know that my question imply to know matlab, and this is not the right place, but i’m a physics student and i don’t quite yet understand this concepts. When i make a LinearModelFit i can get a ...
- asked by Kafkarudo (2 votes)
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[How to assemble and disassemble a function into steps] http://mathematica.stackexchange.com/questions/67325/how-to-assemble-and-disassemble-a-function-into-steps
I’ve watched many programmers (both novice and expert) write functions in Mathematica and have observed a common behavioral pattern. This pattern has many elements that would be automated and thus ...
- asked by user5601 (3 votes)
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[Mathematica 10 and Mac] http://mathematica.stackexchange.com/questions/67552/mathematica-10-and-mac
This might be a the wrong place to post the question, but I am sure that there would be few places where I would find people who would know more about how mathematica works.
I am looking to buy a new ...
- asked by ALEXANDER (2 votes)
================================== Top new questions this week: ==================================
[Wind Map Artwork] http://mathematica.stackexchange.com/questions/66936/wind-map-artwork
I would like some help generating an image like the one seen below.
The image above is an art piece called Wind Map by artists Fernanda Viegas and Martin Wattenberg.
I would like to take wind ...
- asked by James Rohal (15 votes), answered by Silvia (10 votes)
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[Visual representation of a Ranking over time (image provided)] http://mathematica.stackexchange.com/questions/66581/visual-representation-of-a-ranking-over-time-image-provided
[Disclaimer: I initially posted this question on stackOverflow 2 months ago and think it might be better suited for this forum (link to original question)]
The graph below shows a ranking of ...
- asked by Seb (15 votes), answered by belisarius (17 votes)
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[Drawing a square root spiral] http://mathematica.stackexchange.com/questions/66969/drawing-a-square-root-spiral
Here is a start, i’m looking for a nice way.
Graphics[{EdgeForm[Black], White, Polygon@{{0, 0}, {-1, 0}, Sqrt[2] {Cos[#], Sin[#]} &[Pi - (ArcCot[1])]}, Polygon@{{0, 0}, Sqrt[2] ...
- asked by mathe (12 votes), answered by Bob Hanlon (7 votes)
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[Mathematica, animations, and external ray tracing programs] http://mathematica.stackexchange.com/questions/66638/mathematica-animations-and-external-ray-tracing-programs
As much as I enjoy and admire Mathematica’s animation capabilities, I would like to take my animations to the next level by exporting the geometry of every frame to an external ray tracing program ...
- asked by Kim Fierens (11 votes), answered by Alexey Popkov (4 votes)
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[Combine Stereographic "Entity" Plot of Arctic Sea with Contour Plot] http://mathematica.stackexchange.com/questions/66562/combine-stereographic-entity-plot-of-arctic-sea-with-contour-plot
In the announcement of Mathematica 10 there were some very cool features for every geo-related researcher. Like this one
what i’m trying to do is to overlay an ContourPlot onto this beautiful arctic ...
- asked by Julian Carpenter (10 votes), answered by FJRA (3 votes)
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[Generating Random Real numbers with certain numbers not included] http://mathematica.stackexchange.com/questions/66756/generating-random-real-numbers-with-certain-numbers-not-included
I’m writing a program that i need 1000 real number between -3 and 6. the code that I used for generating and saving them was
l = RandomReal[-3, 6, 1000]
But I want to be sure none of these ...
- asked by user2838619 (9 votes), answered by belisarius (9 votes)
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[Detect implicit grid in image with monospaced characters] http://mathematica.stackexchange.com/questions/66886/detect-implicit-grid-in-image-with-monospaced-characters
I’m trying to detect the monospaced-grid in a possibly slightly deformed image of a receipt. Example input (full size here)
My idea is to obtain the centroids or bounding boxes of all components ...
- asked by Thijs (8 votes), answered by belisarius (9 votes)
================================== Greatest hits from previous weeks: ==================================
[Assign the results from a Solve to variable(s)] http://mathematica.stackexchange.com/questions/6669/assign-the-results-from-a-solve-to-variables
I understand Mathematica can’t assign the results of a Solve to the unknowns because there may be more than 1 solution. How can I assign the 4 values of following result to variables?
- asked by stevenvh (16 votes), answered by Artes (10 votes)
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[Generating visually pleasing circle packs] http://mathematica.stackexchange.com/questions/40334/generating-visually-pleasing-circle-packs
EDIT: (my conclusion and thank you note) I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you had fun and enjoyed it the same as I did.
I would like to ...
- asked by VividD (67 votes), answered by level1807 (42 votes)
================================== Can you answer these? ==================================
[Lists for built-in functions that can work without brackets] http://mathematica.stackexchange.com/questions/67039/lists-for-built-in-functions-that-can-work-without-brackets
I just noticed that Exit and Quit can work without brackets i.e. a single
Exit
or
Quit
will quit the kernel. Quite surprising!
This isn’t mentioned in the document of them. Is there a list for ...
- asked by xzczd (3 votes)
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[ImportString JSON possible bug] http://mathematica.stackexchange.com/questions/67076/importstring-json-possible-bug
My problem is when I catch up some json output of whatever method and process it with ImportString[%, "JSON"], The first time when it executes, it works and then without doing anything, it stops ...
- asked by d555 (4 votes)
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[Fractals or other patterns in the quadruple linked pendulum] http://mathematica.stackexchange.com/questions/67012/fractals-or-other-patterns-in-the-quadruple-linked-pendulum
This will seem like a physics question, but I’m looking for something to do in Mathematica specifically. I’ve successfully modeled a quadruple linked pendulum by setting up the ODEs and solving them ...
- asked by Lonely Mathematician (3 votes)
================================== Top new questions this week: ================================== [Is it possible to draw really thin lines in Mathematica?]\url{http://mathematica.stackexchange.com/questions/66177/is-i t-possible-to-draw-really-thin-lines-in-mathematica} I want to have in Mathematica the same result I have in Python: I have this nice effect simply by using very thin lines. But it seems in Mathematica thickness property has some limit and i just got ... - asked by funnypony (18 votes), answered by Alexey Popkov (18 votes) ---------------------------- [How to write Morse code into Plot Dashing?]\url{http://mathematica.stackexchange.com/questions/66267/how-to-w rite-morse-code-into-plot-dashing} How can we define a dashing pattern in a plot such that it reads arbitrary text in Morse code? For instance Graphics[{DotDashed, Line[{{0, 0}, {5, 0}}]}] this could be interpreted as ".-" ... - asked by rhermans (14 votes), answered by rhermans (20 votes) ---------------------------- [How do I draw a pair of buttocks?]\url{http://mathematica.stackexchange.com/questions/66538/how-do- i-draw-a-pair-of-buttocks} I'm trying to develop a function which 3D plot would have a buttocks like shape. Several days of searching the web and a dozen my of own attempts to solve the issue have brought nothing but two ... - asked by Simpleton Jack (11 votes), answered by gpap (20 votes) ---------------------------- [Automatically execute command after save]\url{http://mathematica.stackexchange.com/questions/66239/automaticall y-execute-command-after-save} I want to run some code automatically after saving my notebook. Is there a $ variable or setting for this? - asked by Giovanni (10 votes), answered by funnypony (13 votes) ---------------------------- [Minesweeper beta : How to Dynamic a lot of graphics with high-speed] \url{http://mathematica.stackexchange.com/questions/66133/minesw eeper-beta-how-to-dynamic-a-lot-of-graphics-with-high-speed} Recently I want to write a game,Minesweeper.Here is my completed code. Clear["Global`*"] path = "http://i.stack.imgur.com//" <> # &; filenames1 = {"P22Go.jpg", "Zh27M.jpg", "vKZZr.jpg", ... - asked by Chenminqi (8 votes) ---------------------------- [Is plot polluting my context?]\url{http://mathematica.stackexchange.com/questions/66255/is-plot- polluting-my-context} Whenever I plot something 3 temporary variables get added to my current context. Example (fresh Kernel): Plot[x, {x, -1, 1}]; Names["Global`*"] Output: {"x", "$3", "$4", "$5"} When I do the ... - asked by Max1 (8 votes) ---------------------------- [How to subtract one list from another, treating each elements as distinct?]\url{http://mathematica.stackexchange.com/questions/66079/how-to- subtract-one-list-from-another-treating-each-elements-as-distinct} Suppose that I have a = {"A", "A", "A", "B", "B", "C"} b = {"A", "B"} How can I subtract b from a such that the result is {"A", "A", "B", "C"}? One solution I can think of is to use ... - asked by Taiki (8 votes), answered by Kuba (8 votes) ================================== Greatest hits from previous weeks: ================================== [Get a "step by step" evaluation in Mathematica] \url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (60 votes), answered by J.M. (51 votes) ---------------------------- [How to create a new "person curve"?]\url{http://mathematica.stackexchange.com/questions/17704/how-to-cr eate-a-new-person-curve} Wolfram|Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica notebook, or person curve into ... - asked by Simon (48 votes), answered by Vitaliy Kaurov (21 votes) ================================== Can you answer these? ================================== [Mod[1.2, 0.2] is not equal to zero]\url{http://mathematica.stackexchange.com/questions/66386/mod1-2-0-2-i s-not-equal-to-zero} I'm new to mathematica but this doesn't seem to make any sence In[1]:=Mod[1.2, 0.2] Out[1]=0.2 Why is it not zero? Edit: This is what I wanted to do: xgrid = Table[{i,If[Mod[i, 0.2] == 0 , ... - asked by Patrick Chin (2 votes) ---------------------------- [Parsing RLink RObject for summary.aovlist]\url{http://mathematica.stackexchange.com/questions/66506/p arsing-rlink-robject-for-summary-aovlist} There's some slightly similar requests out there (e.g. Getting R textual output into Mathematica ) but I'm wondering if anyone has put together a more general purpose solution to parsing RObject[] ... - asked by flip (1 vote) ---------------------------- [Implement a piecewise function elegantly and efficiently]\url{http://mathematica.stackexchange.com/questions/66209/imple ment-a-piecewise-function-elegantly-and-efficiently} Given that $$ g(x)= \begin{cases} max(x_{min},x-m) & 0.5x \leq max(x_{min},x-m) \\ 0.5x & max(x_{min},x-m)<0.5x<min(1,x+m) \\ min(1,x+m) & min(1,x+m)\leq 0.5x \end{cases}$$ ... - asked by ShutaoTang (4 votes)
================================== Top new questions this week: ================================== [How to extract a list of available Method-s]\url{http://mathematica.stackexchange.com/questions/65680/how-to-e xtract-a-list-of-available-method-s} The option Methodapplies for several functions, such as NDSolve, FindRoot, NIntegrate and some others. It is difficult, however, to find a list of Methods for a given function. By digging through ... - asked by Alexei Boulbitch (16 votes), answered by Nasser (18 votes) ---------------------------- [How to programmatically extract mathematical formulas from Word with Mathematica 9?]\url{http://mathematica.stackexchange.com/questions/65666/how-to-program matically-extract-mathematical-formulas-from-word-with-mathematica} I have a bunch of(1000+) Microsoft Word document in .Docx format. How can I programmatically extract the mathematical formulas from MS Word using Mathematica 9? This is what example looks like (or ... - asked by Xiang Li (15 votes), answered by WolframFan (15 votes) ---------------------------- [Why is TextString[-0.5] a positive number?]\url{http://mathematica.stackexchange.com/questions/65600/why-is-te xtstring-0-5-a-positive-number} I want to format numbers in decimal notation and chose TextString for this task. But today, when looking at the final result of my 3-weeks measurement, the sign seemed odd. I traced it to the ... - asked by Martin J.H. (14 votes), answered by Szabolcs (10 votes) ---------------------------- [Quickly test if all element in list is the same]\url{http://mathematica.stackexchange.com/questions/65782/quickly-test -if-all-element-in-list-is-the-same} I'm running a Monte Carlo simulation. At the end, I want to count how many simulations return a list of same element. My problem: SimulationResult = (* n x m matrix of real numbers *) c = ... - asked by Zoff Dino (12 votes), answered by Michael E2 (9 votes) ---------------------------- [Efficient way to compare animated images to tell if they are the same]\url{http://mathematica.stackexchange.com/questions/65794/efficient-wa y-to-compare-animated-images-to-tell-if-they-are-the-same} I have a Student license for Mathematica, and felt like I wasn't making full use of the wonderful toolkit that it is; so I looked into things like its image processing capabilities. Now, I made and ... - asked by Austin Burk (11 votes), answered by Pickett (7 votes) ---------------------------- [A one line proof that one is zero using Mathematica 10]\url{http://mathematica.stackexchange.com/questions/65624/a-one-line-pro of-that-one-is-zero-using-mathematica-10} a = (Sqrt[2] + 1) (Sqrt[2] - 1) - 1; {a/a, Simplify[a]/a, b/b == Simplify[b]/b} {1, 0, True} This one line "proof" that one equals zero is disturbing (and could possibly lead to wrong results ... - asked by Gregoire Nicollier (11 votes), answered by Szabolcs (22 votes) ---------------------------- [Curve fitting by running through hundreds of models and return the one with best fit]\url{http://mathematica.stackexchange.com/questions/65757/curve-fitting -by-running-through-hundreds-of-models-and-return-the-one-with-best} In the past, I used to solve a lot of my regression analysis (curve fitting) problems with a program called DataFit which runs on Windows. It has hundreds of regression models which it runs through in ... - asked by MathLind (9 votes), answered by kguler (17 votes) ================================== Greatest hits from previous weeks: ================================== [How to create a new "person curve"?]\url{http://mathematica.stackexchange.com/questions/17704/how-to-cr eate-a-new-person-curve} Wolfram|Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica notebook, or person curve into ... - asked by Simon (47 votes), answered by Vitaliy Kaurov (20 votes) ---------------------------- [Numerically solving Helmholtz equation in 2D for arbitrary shapes]\url{http://mathematica.stackexchange.com/questions/56305/numericall y-solving-helmholtz-equation-in-2d-for-arbitrary-shapes} I would like to solve the Helmholtz equation with dirichlet boundary conditions in 2 dimensions for an arbitrary shape. (for a qualitative comparison of the eigenstates to periodic orbits in the ... - asked by Julian S. (35 votes), answered by Mark McClure (30 votes) ================================== Can you answer these? ================================== [Find d'Alembertian in the output and convert into Einstein summation convention form]\url{http://mathematica.stackexchange.com/questions/65469/find-dalembe rtian-in-the-output-and-convert-into-einstein-summation-convention} I am trying to do field variations in Mathematica and would like some nice formatting. My output is in the form $ -\frac{1}{c^2}V^{(1,0,0,0)}[t,x,y,z] + ... - asked by SlipStream (2 votes) ---------------------------- [remote kernel through SSH]\url{http://mathematica.stackexchange.com/questions/65953/remote-kernel -through-ssh} Is it possible to setup connection to remote kernels through ssh? I'm able to SSH into the remote server(linux) and start a kernel in the terminal, but it can't connect back to my local front end. I ... - asked by xslittlegrass (3 votes) ---------------------------- [Understanding polyharmonic splines]\url{http://mathematica.stackexchange.com/questions/65763/understan ding-polyharmonic-splines} Raul Narain and J.M. gives implementation of the thin plate polyharmonic splines in this post. Raul Narian's method is clear. J.M.'s is convenient to reuse. But J.M. used too many ... - asked by xibinke (1 vote)
================================== Top new questions this week: ================================== [Exclude data from a list]\url{http://mathematica.stackexchange.com/questions/65246/exclude-data -from-a-list} Let's create some random sample data data = Table[{RandomReal[{-10, 10}], RandomReal[{-10, 10}]}, {i, 1, 300}]; Then we plot them using ListPlot L0 = ListPlot[data, Frame -> True, Axes -> ... - asked by Vaggelis_Z (13 votes), answered by kguler (15 votes) ---------------------------- [How do I understand ListCorrelate(contains $\{k_L,k_R\}$) when it works for 2-dimentional data?]\url{http://mathematica.stackexchange.com/questions/64925/how-do-i-un derstand-listcorrelatecontains-k-l-k-r-when-it-works-for-2-di} Two months ago, I asked a question here And @nikie give me a solution: The intuitive way to understand ListCorrelate is that the kernel is "moved" to every position in the array, and the sum of ... - asked by ShutaoTang (12 votes), answered by Simon Woods (11 votes) ---------------------------- [Using 0 to create new columns in a list with Part]\url{http://mathematica.stackexchange.com/questions/65200/using-0-to-c reate-new-columns-in-a-list-with-part} I just discovered a nice way to create intermediary columns in a list, and I would like to know if I can have some problem with it. It Works like this: Imagine I have this list, 5x3: SeedRandom[0] ... - asked by Murta (10 votes), answered by Mr.Wizard (12 votes) ---------------------------- [Glitch in Filling?]\url{http://mathematica.stackexchange.com/questions/64988/glitch-i n-filling} I ran into a problem while plotting and I was able to narrow it to this. Before I start "spelunking" I'd like to know if I am overlooking something or if this is a problem others have worked through. ... - asked by Mr.Wizard (9 votes), answered by ybeltukov (5 votes) ---------------------------- [Multiple-colored regions on a Sphere in Mathematica]\url{http://mathematica.stackexchange.com/questions/65174/multi ple-colored-regions-on-a-sphere-in-mathematica} The problem: I would like to draw a sphere where the bottom half is one color, and the top half is split into 3 equal regions, each with its own color. I have come up with the following code, by ... - asked by Nick Lassonde (8 votes), answered by Michael E2 (8 votes) ---------------------------- [Is there a way to control V10's undo length?]\url{http://mathematica.stackexchange.com/questions/65055/is-there- a-way-to-control-v10s-undo-length} This may be a duplicate (if so I will remove this), but I was having trouble finding the relevant bit of documentation to fix it. I noticed that my FrontEnd memory use was growing out of control when ... - asked by DumpsterDoofus (8 votes), answered by rm -rf (6 votes) ---------------------------- [What is the best way to draw a shaded table?]\url{http://mathematica.stackexchange.com/questions/65356/what-is-th e-best-way-to-draw-a-shaded-table} I'm trying to format a raster-style table with row and column headings and in which each cell is shaded according to the value in the cell, and the value of the cell is displayed in as text in a ... - asked by raxacoricofallapatorius (6 votes), answered by Arnoud Buzing (7 votes) ================================== Greatest hits from previous weeks: ================================== [Get a "step by step" evaluation in Mathematica] \url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (58 votes), answered by J.M. (50 votes) ---------------------------- [Why round to even integers?] \url{http://mathematica.stackexchange.com/questions/2116/why-roun d-to-even-integers} According to the Mathematica help: Round rounds numbers of the form x.5 toward the nearest even integer. For example: Round[{0.5, 1.5, 2.5, 3.5, 4.5}] gives {0, 2, 2, 4, 4} What's the ... - asked by wxffles (26 votes), answered by Per Alexandersson (22 votes) ================================== Can you answer these? ================================== [Sizing elements correctly in a DistributionChart with custom ChartElementFunction]\url{http://mathematica.stackexchange.com/questions/65 395/sizing-elements-correctly-in-a-distributionchart-with-custom-chartel ementfunctio} This is a follow-up question to Histogram scale error when using DistributionChart; Weird output of DistributionChart is also related. I'd like to make a DistributionChart where the elements are ... - asked by Daniel Weissman (1 vote) ---------------------------- [Capturing microphone data]\url{http://mathematica.stackexchange.com/questions/65276/capturing-mi crophone-data} How to capture current microphone data, just like using the function CurrentImage[] for capturing image? For example, this captures an image: Dynamic [x = CurrentImage []; EdgeDetect [x, 3]] But I ... - asked by Dragan Mrakovic (3 votes) ---------------------------- [How to download and combine S&P 500 stock prices]\url{http://mathematica.stackexchange.com/questions/65386/how-to-dow nload-and-combine-sp-500-stock-prices} I want to download historical S&P 500 stock prices and combined them into one big file, having only one column of date referencing all stocks. Here is what I have do so far. stdate = ... - asked by rka (5 votes)
================================== Top new questions this week: ================================== [DumpsterDoofus's captivating generative art]\url{http://mathematica.stackexchange.com/questions/64492/dumpsterdoofu ss-captivating-generative-art} How can I render these beautiful images that DumpsterDoofus posted? - asked by Mr.Wizard (23 votes), answered by DumpsterDoofus (24 votes) ---------------------------- [Is there an easy way to use Matteo Niccoli's perceptual color maps for 2D plots in Mathematica?]\url{http://mathematica.stackexchange.com/questions/64513/is-t here-an-easy-way-to-use-matteo-niccolis-perceptual-color-maps-for-2d-plo ts} I have been using the ubiquitous Jet color palette for 2D plots for some time now, and don't really care for it. Then I came across the series of blog posts, The rainbow is dead...long live the ... - asked by Jason B (22 votes), answered by Jason B (20 votes) ---------------------------- [How to wrap a plot around a circle?]\url{http://mathematica.stackexchange.com/questions/64534/how-to-wr ap-a-plot-around-a-circle} Consider the code a = Table[BesselJ[i, x], {i, 0, 3}] Plot[a, {x, 0, 20}, Axes -> False] producing I'd like to transform the plot into a circle. In other words, I'd like to wrap the plot ... - asked by Sigur (14 votes), answered by Junho Lee (15 votes) ---------------------------- [Which Mathematica function has the longest name (by character length?)]\url{http://mathematica.stackexchange.com/questions/64718/which-ma thematica-function-has-the-longest-name-by-character-length} I came across DamerauLevenshteinDistance[u,v] in the documentation center so that got me thinking: Which documented Mathematica function has the longest name? Also, is there is a limit to the length ... - asked by QuantumDot (11 votes), answered by Artes (18 votes) ---------------------------- [Phase portrait on a cylinder]\url{http://mathematica.stackexchange.com/questions/64407/phase-po rtrait-on-a-cylinder} It is very nice and very easy to make a sketch of a phase portrait with StreamPlot. For example, for the classical pendulum, defined by $$ \dot x=y,\\ \dot y=-\sin x, $$ The code StreamPlot[{y, ... - asked by Artem (10 votes), answered by Kuba (12 votes) ---------------------------- [Why does the documentation call functions "pure"?]\url{http://mathematica.stackexchange.com/questions/64577/why-does- the-documentation-call-functions-pure} Clearly, functions in mathematica are not pure functions according to the definition on Wikipedia (no side effects - basically implementabe with table lookups): x = 4; y = 1; a = Function[y = 0; x + ... - asked by masterxilo (9 votes), answered by WReach (7 votes) ---------------------------- [Rasterize: Resolution option not working properly]\url{http://mathematica.stackexchange.com/questions/64758/rasteriz e-resolution-option-not-working-properly} Something about Rasterize which doesn't seem to work as intended. Recipe: Make some simple vector graphics: Test = Graphics[Circle[{0, 0} 1]] Try to rasterize it having defined ImageSize and ... - asked by Alexey Bobrick (8 votes), answered by Alexey Popkov (5 votes) ================================== Greatest hits from previous weeks: ================================== [How can I draw the Olympic rings with Mathematica?]\url{http://mathematica.stackexchange.com/questions/8885/how-c an-i-draw-the-olympic-rings-with-mathematica} How can I draw the 5 interlocking Olympic rings with Mathematica? (SVG version) Edit Hard choice, but some pretty cool answers here. I didn't have 3D answers in mind when I posted the question ... - asked by Mike Honeychurch (33 votes), answered by cormullion (15 votes) ---------------------------- [Why round to even integers?]\url{http://mathematica.stackexchange.com/questions/2116/why-roun d-to-even-integers} According to the Mathematica help: Round rounds numbers of the form x.5 toward the nearest even integer. For example: Round[{0.5, 1.5, 2.5, 3.5, 4.5}] gives {0, 2, 2, 4, 4} What's the ... - asked by wxffles (26 votes), answered by Per Alexandersson (22 votes) ================================== Can you answer these? ================================== [Dependent probabilities distributions?]\url{http://mathematica.stackexchange.com/questions/64719/de pendent-probabilities-distributions} What's the best way to model situations with dependencies--I pick a world state, then pick a distribution to draw samples from based on that state. Here's a concrete version: If I choose a 6-sided ... - asked by Victor Shnayder (1 vote) ---------------------------- [How to get data from DB into dataset with keys]\url{http://mathematica.stackexchange.com/questions/64391/how-to-get-d ata-from-db-into-dataset-with-keys} I'm a Mathematica newbie and I have the following problem: I connect to a Oracle DB and read out a set of variables, further on I want to histogram some of the variables. A Dataset seems to be the ... - asked by Lea (4 votes) ---------------------------- [Max iterations in K-means clustering algorithm]\url{http://mathematica.stackexchange.com/questions/64343/max-ite rations-in-k-means-clustering-algorithm} I want to use k-means for clustering. I have used the ClusteringComponents function but I said how can I control the max-iteration for k-means ? - asked by Developer2000 (2 votes)
================================== Top new questions this week: ================================== [Why do big-O terms disappear in definite integrals since Mathematica 9?]\url{http://mathematica.stackexchange.com/questions/64318/why-do-big-o-t erms-disappear-in-definite-integrals-since-mathematica-9} In Mathematica 8, when I computed the following input: Integrate[Series[Cos[x], {x, 0, 2}], {x, 0, a}] Mathematica returned an expression that had a O[a^4] in it. (In other words, the result had ... - asked by Martin J.H. (4 votes) ---------------------------- [How to track Part of Symbol or How to symbolize Parts of Symbol without copying data]\url{http://mathematica.stackexchange.com/questions/64312/how-to-track -part-of-symbol-or-how-to-symbolize-parts-of-symbol-without-copying} Let's create simple function: SetAttributes[h, HoldFirst]; h[data_] := Dynamic[Grid[data], TrackedSymbols :> {data}] test = RandomReal[1, {2, 2}]; h[test] Now you can evaluate somewhere else: ... - asked by Kuba (1 vote) ---------------------------- [Unimportant change in Dynamic]\url{http://mathematica.stackexchange.com/questions/64310/unimporta nt-change-in-dynamic} I just observed an unimportant change in version 10 with respect to Dynamic. The command x=0; Dynamic[x=x+1] returns a cell showing an infinite loop for the value of x. Before Mathematica 10, ... - asked by Fred Simons (2 votes) ---------------------------- [Classify Function : Sentiment Polarity]\url{http://mathematica.stackexchange.com/questions/64306/classify -function-sentiment-polarity} I have been working on a project involving the new Classify[] function. More specifically, the sentiment analysis function. It works perfectly well, as in the documentation: Classify["Sentiment", { ... - asked by afentis (1 vote), answered by rcollyer (0 votes) ---------------------------- [User defined functions and decimal places displayed]\url{http://mathematica.stackexchange.com/questions/64284/user-de fined-functions-and-decimal-places-displayed} I have a couple of complicated user-defined functions, one which calls the other, and I wish to control the number of decimal places displayed when I call the "mother" function. I have tried the ... - asked by Freakalien (1 vote), answered by Mr.Wizard (1 vote) ---------------------------- [aligning the axeslabel in a 3D list plot]\url{http://mathematica.stackexchange.com/questions/64280/aligning-the -axeslabel-in-a-3d-list-plot} I have the following code plot = ListPlot3D[mydata5, DataRange -> {{0, 6}, {0, 6}}, PerformanceGoal -> "Quality", BoxRatios -> {1, 1, .7}, AxesLabel -> {Style[Subscript[t, l], FontSize ... - asked by Seyhmus Gungoren (1 vote), answered by xzczd (1 vote) ---------------------------- [Solving system of differential equations using loops]\url{http://mathematica.stackexchange.com/questions/64278/solving-sys tem-of-differential-equations-using-loops} I have $F$ system of differential equations. Out of those $F$ equations except for first and last I have general form for the remaining equations (say $ dP_{i}/dt)$. Let $dP_0/dt,dP_F/dt$ denotes the ... - asked by user1659936 (1 vote), answered by Michael E2 (1 vote) ================================== Greatest hits from previous weeks: ================================== [Implementing efficient multiple undo]\url{http://mathematica.stackexchange.com/questions/1953/implementing- efficient-multiple-undo} At the time this question was asked, version 10 was not out yet. The Front End of Mathematica 10 does have multiple undo, see the answer by John Fultz. The Mathematica Front End's built-in Undo ... - asked by Rojo (111 votes), answered by John Fultz (34 votes) ---------------------------- [Programming paradigm change]\url{http://mathematica.stackexchange.com/questions/45829/programmin g-paradigm-change} I'm new to Mathematica, I've been learning by myself, and, being a Java developer for some time, it makes it hard to adapt. I've tried to solve a Reddit challenge, and I came up with this solution: ... - asked by MHero (29 votes), answered by WReach (49 votes) ================================== Can you answer these? ================================== [FindSequenceFunction for sum of hypergeometric terms]\url{http://mathematica.stackexchange.com/questions/64168/findsequenc efunction-for-sum-of-hypergeometric-terms} Mathematica's built-in function FindSequenceFunction is quite good at recognizing hypergeometric terms, i.e. terms $c_k$ for which $c_{k+1}/c_k$ is a rational function of $k$. For instance. ... - asked by Eckhard (4 votes) ---------------------------- [Finding the minimum vertex cut of a graph]\url{http://mathematica.stackexchange.com/questions/63783/finding-the-minimum-vertex-cut-of-a-graph} It seems that Mathematica is not correctly finding the smallest set of vertices that will disconnect a graph. Here is an example: g = GraphData[{"Cycle", 5}] FindVertexCut[g]; HighlightGraph[g, %] ... - asked by Lonely Mathematician (3 votes) ---------------------------- [NMaximize gives wrong answer when using high precision] \url{http://mathematica.stackexchange.com/questions/64256/nmaximize-gives-wrong-answer-when-using-high-precision} I'm using NMaximize to find the maximum of a function under constrain, but it seems to gives wrong answer when using high precisions. f[t_, t1_] := (Cos[2 Pi t] - Cos[2 Pi t1] + 2 Pi (t - t1) Sin[2 Pi ... - asked by xslittlegrass (1 vote)
================================== Top new questions this week: ================================== [Total much slower in version 10]\url{http://mathematica.stackexchange.com/questions/63209/total-much-slo wer-in-version-10} Compilation nowadays may give very fast functions. Here is an example for finding the sum of a list of machine numbers, just as the built-in function Total: myTotal = Compile[{{lst, _Real, 1}}, ... - asked by Fred Simons (15 votes), answered by Karsten 7. (5 votes) ---------------------------- [Drawing the schematic diagram of algorithm]\url{http://mathematica.stackexchange.com/questions/63471/drawing -the-schematic-diagram-of-algorithm} The B-Spline function used the alogrithm as shown below: I would like to draw it in Mathematica (Although this is my first time to use TreePlot) TreePlot[ {1 -> 2, 1 -> 3, 2 -> 4, ... - asked by ShutaoTang (14 votes), answered by kguler (9 votes) ---------------------------- [How can I evaluate only a single step of a recursive function?]\url{http://mathematica.stackexchange.com/questions/63256/how-can -i-evaluate-only-a-single-step-of-a-recursive-function} Let's say have a simple recursive function for the Fibonacci sequence f[0] := 1 f[1] := 1 f[n_] := f[n - 1] + f[n - 2] but I want to see how it will expand in a given number of steps, but not all ... - asked by Jakub Arnold (12 votes), answered by Daniel Lichtblau (16 votes) ---------------------------- [How to build a 3D graph from a 3D matrix?]\url{http://mathematica.stackexchange.com/questions/63428/how-to-bu ild-a-3d-graph-from-a-3d-matrix} Following this and that question and the corresponding answers, Mathematica can build 2D graph from 2D matrices. Question How to make the corresponding 3D graphs from 3D cubes? Attempt ... - asked by chris (11 votes), answered by kguler (5 votes) ---------------------------- [Listable functions thread over Associations; is this documented?]\url{http://mathematica.stackexchange.com/questions/63293/lista ble-functions-thread-over-associations-is-this-documented} Thanks to a somewhat misapplied use of MapThread I learned of this behavior: <|a -> 1, b -> 2|> + <|a -> 5, b -> 6|> <|a -> 6, b -> 8|> Furthermore this ... - asked by Mr.Wizard (10 votes), answered by m_goldberg (3 votes) ---------------------------- [Bug(?) in version 10: Tooltip and ListPointPlot3D]\url{http://mathematica.stackexchange.com/questions/63667/b ug-in-version-10-tooltip-and-listpointplot3d} Bug introduced in 10.0.0 The coordinates of a point in a three dimensional graph can be shown in a tooltip: ListPointPlot3D[Tooltip[RandomReal[{0, 1}, {50, 3}]], PlotStyle -> {PointSize[.02]}] ... - asked by Fred Simons (9 votes) ---------------------------- [How to align rotated BarChart labels?]\url{http://mathematica.stackexchange.com/questions/63263/how-to-al ign-rotated-barchart-labels} I'd like to use long text labels for a simple BarChart, but when I apply a rotation to label strings with different lengths the end of the text is no longer aligned with the bars in the chart: ... - asked by dionys (9 votes), answered by Brett Champion (10 votes) ================================== Greatest hits from previous weeks: ================================== [How to make use of Associations?]\url{http://mathematica.stackexchange.com/questions/52393/how -to-make-use-of-associations} I have been curious about it for long. Now that Mathematica 10 arrives, I think it's time to ask the question: How the new Association data structure would be used to improve Mathematica programming? ... - asked by Yi Wang (53 votes), answered by Leonid Shifrin (54 votes) ---------------------------- [Programming paradigm change]\url{http://mathematica.stackexchange.com/questions/45829/programmin g-paradigm-change} I'm new to Mathematica, I've been learning by myself, and, being a Java developer for some time, it makes it hard to adapt. I've tried to solve a Reddit challenge, and I came up with this solution: ... - asked by MHero (28 votes), answered by WReach (48 votes) ================================== Can you answer these? ================================== [Visualise sets giving some relations on those sets]\url{http://mathematica.stackexchange.com/questions/63391/visualise-se ts-giving-some-relations-on-those-sets} I'm not very experienced with wolfram, but I'm searching for a function that can basicly do the following. Giving some sets $A,B,C$ and some relations for example $B \subset A$,$C\subset B$. I would ... - asked by Kasper (1 vote) ---------------------------- [StyleSheet for custom application]\url{http://mathematica.stackexchange.com/questions/63313/style sheet-for-custom-application} I'm working on a package that for some reasons needs to be installed into a "non standard" path, that means neither $BaseDirectory or $UserBaseDirectory I added the package's path to the variable ... - asked by bobknight (1 vote) ---------------------------- [ListContourPlot in V10]\url{http://mathematica.stackexchange.com/questions/63653/listcontourpl ot-in-v10} It seems that I obtain different results when using ListContourPlot under V9 and V10. Using this datafile http://pastebin.com/2p4ew0NJ (modified to use pastebin), this code: ListContourPlot[cm, ... - asked by alessandro (1 vote)
================================== Top new questions this week: ================================== [Assign a randomly generated list to variable]\url{http://mathematica.stackexchange.com/questions/62921/assign-a -randomly-generated-list-to-variable} I don't know if this is a silly question, but it really baffles me. So please help me understand this behavior. list=RandomInteger[100,100] I interpret the (silly) code above as randomly generating ... - asked by Naitree (19 votes), answered by rhermans (5 votes) ---------------------------- [Dataset seems unable to handle ListDensityPlot and ListContourPlot]\url{http://mathematica.stackexchange.com/questions/61572/d ataset-seems-unable-to-handle-listdensityplot-and-listcontourplot} If I create a Dataset: dataSet = Dataset[ AssociationThread[{"a", "b", "c", "d", "e"} -> #] & /@ RandomReal[{-1, 1}, {1000, 5}] ]; It should be easy to use a plotting function on it ... - asked by gpap (15 votes), answered by RunnyKine (14 votes) ---------------------------- [Make my data-structure atomic]\url{http://mathematica.stackexchange.com/questions/61587/make-my-da ta-structure-atomic} Lately, and by lately I mean since version 7 or so, the number of atomic expressions in Mathematica constantly grew. In former times only the native types like integers and optimised arrays were ... - asked by halirutan (14 votes), answered by Leonid Shifrin (10 votes) ---------------------------- [Applying different functions to different columns of a Dataset]\url{http://mathematica.stackexchange.com/questions/61710/applying- different-functions-to-different-columns-of-a-dataset} Suppose I have different functions: Total, Mean and Max and the following Dataset SeedRandom[0] dataSet = Dataset[AssociationThread[{"a", "b", "c", "d"} -> #] & /@ RandomReal[4, {10, 4}]] ... - asked by smayhem (13 votes), answered by RunnyKine (9 votes) ---------------------------- [Sorting Lists of lists of arbitrary length]\url{http://mathematica.stackexchange.com/questions/61560/sorting-li sts-of-lists-of-arbitrary-length} I'm trying to sort a list of lists. The sublists are defined in length, but the length of the list containing it varies. A simplified set might be: {{1, 2, 3}, {7, 1, 4}, {3, 5, 6}, {10, 7, 1}} ... - asked by Rick R (10 votes), answered by RunnyKine (11 votes) ---------------------------- [Best way to find permutation with specific total]\url{http://mathematica.stackexchange.com/questions/62956/best-way-to -find-permutation-with-specific-total} Can anyone suggest a good way to find permutations of 12 digits, 0 to 4, totalling 24. I.e. two such permutations:- {2, 1, 4, 1, 2, 2, 2, 2, 2, 2, 1, 3} // Total 24 {4, 4, 4, 4, 4, 4, 0, 0, ... - asked by Chris Degnen (9 votes), answered by thils (6 votes) ---------------------------- [Segmentation of a microscopy image with uneven illumination]\url{http://mathematica.stackexchange.com/questions/62976/segm entation-of-a-microscopy-image-with-uneven-illumination} I am trying to do a little image segmentation on some cells taken from microscopy images that have uneven illumination. I am having trouble getting the background of the image cleaned up after ... - asked by user13999 (9 votes), answered by bobthechemist (4 votes) ================================== Greatest hits from previous weeks: ================================== [Alternatives to procedural loops and iterating over lists in Mathematica]\url{http://mathematica.stackexchange.com/questions/7924/altern atives-to-procedural-loops-and-iterating-over-lists-in-mathematica} While there are some cases where a For loop might be reasonable, it's a general mantra one I subscribe to myself that "if you are using a For loop in Mathematica, you are probably doing it wrong". ... - asked by Mr.Wizard (91 votes), answered by Mr.Wizard (59 votes) ---------------------------- [How to make use of Associations?]\url{http://mathematica.stackexchange.com/questions/52393/how -to-make-use-of-associations} I have been curious about it for long. Now that Mathematica 10 arrives, I think it's time to ask the question: How the new Association data structure would be used to improve Mathematica programming? ... - asked by Yi Wang (53 votes), answered by Leonid Shifrin (54 votes) ================================== Can you answer these? ================================== [Error messages from TensorContract and TensorReduce]\url{http://mathematica.stackexchange.com/questions/61719/erro r-messages-from-tensorcontract-and-tensorreduce} I am struggling with a few errors when using symbolic tensors. I am using mathematica 9.0.1.0, linux x86. The following code generates what seems to me an incorrect tensor, this is the smallest ... - asked by Artur Gower (4 votes) ---------------------------- [Oddify an even function and vice versa?]\url{http://mathematica.stackexchange.com/questions/62957/oddify-an- even-function-and-vice-versa} I want to know how to construct a function in Mathematica which would produce even analog of odd function and vice versa in closed form? The mathematical definitions are as follows: ... - asked by Anixx (2 votes) ---------------------------- [Create SQL Database on a manually specified directory]\url{http://mathematica.stackexchange.com/questions/61568/create- sql-database-on-a-manually-specified-directory} I am inserting lots of data into the preinstalled SQL Database in MM: con= OpenSQLConnection["demo"] > SQLCreateTable[con, SQLTable["anyname"], SQLcolums] > ... I am running out of disk space on my ... - asked by Patrick Bernhard (2 votes)
================================== Top new questions this week: ================================== [Visualisation of a recursive function]\url{http://mathematica.stackexchange.com/questions/61323/visualis ation-of-a-recursive-function} Is there a way to nicely visualize recursive functions? (diagrams/plots) More specifically I'm looking for a way to make contrast (visually) between e.g. the cosine function which if continuously ... - asked by Phonon (16 votes), answered by ybeltukov (23 votes) ---------------------------- [Using an Image as the Fill/Texture (not background) of a Plot (not polygon)]\url{http://mathematica.stackexchange.com/questions/61341/using-an -image-as-the-fill-texture-not-background-of-a-plot-not-polygon} Is it possible to use an image, rather than a color, or ColorFunction, as the filling for a plot? For instance, I want to make a plot using DateListPlot, and have set Filling->Axis, and would like ... - asked by iwantmyphd (11 votes), answered by Jens (4 votes) ---------------------------- [Intelligently formatting PDFs]\url{http://mathematica.stackexchange.com/questions/61209/intelligentl y-formatting-pdfs} I'm exporting a Grid[] to a PDF. It's working, but it's real ugly. Here is an example of what it looks like: Possibly the first problem is the reason I posted a picture of (rather than sharing) the ... - asked by F dot Floss (11 votes), answered by Lou (5 votes) ---------------------------- [How to show matrix multiplication step by step?]\url{http://mathematica.stackexchange.com/questions/61377/how-to-show -matrix-multiplication-step-by-step} Given a matrix, A: A = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}}; How can I do the matrix multiplication A times A step by step? - asked by Mats Granvik (8 votes), answered by ybeltukov (22 votes) ---------------------------- [How to deal with recursion formula in Mathematica?]\url{http://mathematica.stackexchange.com/questions/61050/how- to-deal-with-recursion-formula-in-mathematica} In engineering problems, I am always seeing many recursion formula. For instance, In the book "The NURBS book", I discovered many recursion formula Fibonacci $$f(n+2)=f(n+1)+f(n)$$ deCasteljau ... - asked by Tangshutao (8 votes), answered by Igor Rivin (6 votes) ---------------------------- [Is there a way to revert to the built-in function after overwritting it using Unprotect]\url{http://mathematica.stackexchange.com/questions/61472/is-ther e-a-way-to-revert-to-the-built-in-function-after-overwritting-it-using-u n} When using Unprotect, we can overwrite a functions definition: Unprotect[Sqrt] Sqrt[x_]="blahblah" Protect[Sqrt] Once this is done, can we revert to the built-in version of Sqrt? - asked by user13675 (7 votes), answered by eldo (8 votes) ---------------------------- [Why PlotStyle->Dashed make everything dashed?]\url{http://mathematica.stackexchange.com/questions/61058/why-plots tyle-dashed-make-everything-dashed} Bug introduced in 10.0.0 -- appears to affect Linux only. It has been really strange for me. I am not sure it's regression after v10.0.1, or something went wrong with my system. After running this ... - asked by Yi Wang (7 votes), answered by Neven Caplar (2 votes) ================================== Greatest hits from previous weeks: ================================== [Are you interested in purchasing David Wagner's "Power programming with Mathematica"?]\url{http://mathematica.stackexchange.com/questions/16485/are -you-interested-in-purchasing-david-wagners-power-programming-with-mathe mat} I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about "Power programming with Mathematica" ... - asked by Todd Allen (109 votes), answered by Todd Allen (159 votes) ---------------------------- [How should I reproduce this colorful swirling gif?]\url{http://mathematica.stackexchange.com/questions/47597/how-should-i -reproduce-this-colorful-swirling-gif} Surfing on the web, I came upon this cool gif: Does any one know how to reproduce this in Mathematica? I have some ideas myself, so I will try to answer this question as well. - asked by Ali (10 votes), answered by Kuba (23 votes) ================================== Can you answer these? ================================== [How to update bundled SQLite library (or driver?) in V10 for OS X]\url{http://mathematica.stackexchange.com/questions/61116/how-to-update-b undled-sqlite-library-or-driver-in-v10-for-os-x} I've been using undocumented Database functions with Mathematica V9 to acces my SQLite database, which is a Firefox-generated database that contains cookies. db = Database`OpenDatabase[ ... - asked by shrx (3 votes) ---------------------------- [Is it possible to implement symbolic sub matrices?]\url{http://mathematica.stackexchange.com/questions/61442/is-it-p ossible-to-implement-symbolic-sub-matrices} The accepted answer in the following link: http://stackoverflow.com/questions/5708208/symbolic-matrices-in-mathemat ica-with-unknown-dimensions provides a functionality to create symbolic matrices ... - asked by Kagaratsch (1 vote) ---------------------------- [Format Mathematica complex number for fortran code use]\url{http://mathematica.stackexchange.com/questions/61432/format-mathem atica-complex-number-for-fortran-code-use} I'm using Mathematica 10. I am trying to write into a file complex number output to then be read by a Fortran code. But when I do : Print[comp, " ", FortranForm[comp]] I get this : ... - asked by berhan (1 vote)
================================== Top new questions this week: ==================================
[Join lists with nested list] http://mathematica.stackexchange.com/questions/60666/join-lists-with-nested-list
Is there a way of smarter way of joining list of the form
l1 = a,b,c; l2 = d,e,f; l3 = g,h,i;
To obtain
a,d,g,b,c,e,f,h,i
The code I have is
{Sequence @@ #1, Flatten[#2]} ...
- asked by mete (14 votes), answered by Junho Lee (9 votes)
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[Different results between V9 and V10 when using Style with Listplot]http://mathematica.stackexchange.com/questions/60929/different-results-between-v9-and-v10-when-using-style-with-listplot
Consider this example:
data = Table[{x, x^2}, {x, -2, 2, 0.1}]; ListPlot[Style[{#1, #2}, PointSize[Abs[#2]/50], Hue[#2]] & @@@ data]
the results from V9 and V10 are as follows:
V9
V10
It ...
- asked by Algohi (13 votes), answered by Brett Champion (7 votes)
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[Bug in Operator Form of StringCases]http://mathematica.stackexchange.com/questions/60871/bug-in-operator-form-of-stringcases
According to the documentation there’s an operator form for StringCases
?StringCases
Here is the normal form
StringCases["abcadcacb", "a" ~~ x_ ~~ "c"] {"abc", "adc"}
Now, the operator ...
- asked by RunnyKine (12 votes), answered by WReach (8 votes)
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[Around the Clock]http://mathematica.stackexchange.com/questions/60728/around-the-clock
I want to produce with Mathematica something like this
Or this
12 hours should be arranged in a pleasing ("rotated") style around / within a rectangle. I don’t ask for the hands - depending on ...
- asked by eldo (12 votes), answered by belisarius (15 votes)
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[How to assign a list of numbers into letter grades]http://mathematica.stackexchange.com/questions/60497/how-to-assign-a-list-of-numbers-into-letter-grades
Here is my list:
collection = 76.6256, 51.9264, 50.238, 14.4203, 80.9205, 12.2036, 2.39568, 38.2747, 12.4422, 29.9621
collection /. {x_ /; x < 50 -> "F"}
and this gives me
...
- asked by Lonely Mathematician (12 votes), answered by belisarius (14 votes)
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[Joining ordered set of points with splines in spiral]http://mathematica.stackexchange.com/questions/60619/joining-ordered-set-of-points-with-splines-in-spiral
I have a collection of points
-0.137445, -0.0103507, -0.0452845, 0.0343154, 0.30498, -0.0118266, -0.0224633, 0.0197979, -0.168469, -0.0197066, 0.0973217, 0.0478612, -0.0441388, ...
- asked by martin (11 votes), answered by Rahul Narain (11 votes)
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[Fitting ellipse to 5 given points on the plane]http://mathematica.stackexchange.com/questions/60779/fitting-ellipse-to-5-given-points-on-the-plane
Five points are required to define a unique ellipse. An ellipse has five degrees of freedom: the \(x\) and \(y\) coordinates of each focus, and the sum of the distance from each focus to a point on the ...
- asked by user153012 (11 votes), answered by Mark McClure (21 votes)
================================== Greatest hits from previous weeks: ==================================
[Efficient way to build a certain quadratic matrix]http://mathematica.stackexchange.com/questions/51798/efficient-way-to-build-a-certain-quadratic-matrix
For odd n I’m looking for a short and swift way to construct with (f.e.)
n = 3
n = 11
n=1111
- asked by eldo (15 votes), answered by RunnyKine (15 votes)
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[Finding all simple paths between two vertices in a graph]http://mathematica.stackexchange.com/questions/25779/finding-all-simple-paths-between-two-vertices-in-a-graph
There are built-in methods to find a shortest path between two vertices in a graph, and the question on finding all shortest paths between two vertices has gathered quite a bit of attention.
A path ...
- asked by mrm (11 votes), answered by trybik (10 votes)
================================== Can you answer these? ==================================
[Weird glitch again!]http://mathematica.stackexchange.com/questions/60623/weird-glitch-again
I have been struggling with these glitches for two days...
A related question I asked is here How to eliminate the white gaps in the graph
Here is the code,
Show[Plot[Sin[x], x, -2 Pi, 2 Pi, ...
- asked by Tony (2 votes)
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[How to solve a PDE with Robin Boundary Condition inside considered region?]http://mathematica.stackexchange.com/questions/60890/how-to-solve-a-pde-with-robin-boundary-condition-inside-considered-region
I’m trying to solve the heat diffusion equation in cylindrical coordinates. The main problem is that I would like to include the Robin Boundary Condition inside considered region in order to simulate ...
- asked by Jerry (1 vote)
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[FITS metadata problem]http://mathematica.stackexchange.com/questions/60639/fits-metadata-problem
Looks to me that the FITS Export is borged. Here is the problem:
When I export out images with accustom metadata into a FITS file, Mathematica truncates and overwrites it.
Here is the metadata I ...
- asked by infocean (1 vote)
================================== Top new questions this week: ================================== [Maple vs. Mathematica]\url{http://mathematica.stackexchange.com/questions/60124/maple -vs-mathematica} I am reading the document "How Maple Compares to Mathematica" found at http://www.maplesoft.com/products/maple/compare/HowMapleComparestoMathem atica.pdf. On page 15 there is an example where ... - asked by Milenko Rubin-Zuzic (16 votes), answered by Mr.Wizard (22 votes) ---------------------------- [StringCases is Confused with Patterns in Version 10.0.1]\url{http://mathematica.stackexchange.com/questions/60156/stringcase s-is-confused-with-patterns-in-version-10-0-1} I observed the following with StringCases when trying to use rules/patterns. Here is a screenshot of the behavior: Not only is the pattern highlighted in red, hovering the mouse over it claims it's ... - asked by RunnyKine (14 votes) ---------------------------- [How can I restore the old `ImageCompose` behaviour?]\url{http://mathematica.stackexchange.com/questions/60048/how-ca n-i-restore-the-old-imagecompose-behaviour} Prior to version 10, if ImageCompose was used to overlay a partially transparent image region over a completely transparent image region, the result would keep the colour of the overlay. Like this: ... - asked by Simon Woods (13 votes), answered by Karsten 7. (3 votes) ---------------------------- [Better way to test that a matrix is upper-triangular?]\url{http://mathematica.stackexchange.com/questions/60081 /better-way-to-test-that-a-matrix-is-upper-triangular} Today, I got to thinking about how to test that a matrix was upper-triangular. So I had a try at it. Algorithm $\quad \quad a_{ij}=0 $ Or $i \leq j$ $\Rightarrow$ $True$ My solution is ... - asked by Tangshutao (13 votes), answered by Mr.Wizard (9 votes) ---------------------------- [How to get Company Logo or Image]\url{http://mathematica.stackexchange.com/questions/60041/how-to-get- company-logo-or-image} I can see that companies have a logo in Wolfram|Alpha when I type in their name but I can't get them in Mathematica. For example searching for Apple, Inc. in W|A one of the outputs is the Apple logo. ... - asked by Edmund (12 votes), answered by eldo (15 votes) ---------------------------- [How to make a 3D topographic globe?]\url{http://mathematica.stackexchange.com/questions/60427/how-to-mak e-a-3d-topographic-globe} I've made some attempt with this dataset of elevation. But I have some trouble with ListSurfacePlot3D, which can not show the globe correctly: And I've checked that the data is out of problem, ... - asked by RexDiego (11 votes), answered by bobthechemist (10 votes) ---------------------------- [Is there a better way to "grow" black tulips?]\url{http://mathematica.stackexchange.com/questions/59905/is-there- a-better-way-to-grow-black-tulips} I used the following clumsy way to obtain a bundle of black tulips. Is there a better way to do so? im = Import["http://i.stack.imgur.com/qclHT.jpg"] cols = DominantColors[im, 9] rim1 = ... - asked by Putterboy (11 votes), answered by ybeltukov (17 votes) ================================== Greatest hits from previous weeks: ================================== [Can Mathematica do symbolic linear algebra?]\url{http://mathematica.stackexchange.com/questions/3242/can-mathe matica-do-symbolic-linear-algebra} For instance, is there some way I can say "let A and B be arbitrary real $m\times n$ and $k\times m$ matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ... - asked by nikie (24 votes), answered by helen (12 votes) ---------------------------- [Why round to even integers?]\url{http://mathematica.stackexchange.com/questions/2116/why-roun d-to-even-integers} According to the Mathematica help: Round rounds numbers of the form x.5 toward the nearest even integer. For example: Round[{0.5, 1.5, 2.5, 3.5, 4.5}] gives {0, 2, 2, 4, 4} What's the ... - asked by wxffles (26 votes), answered by Per Alexandersson (22 votes) ================================== Can you answer these? ================================== [Solving a system of two nonlinear equations with many symbolic parameters]\url{http://mathematica.stackexchange.com/questions/59930/solvin g-a-system-of-two-nonlinear-equations-with-many-symbolic-parameters} I have two nonlinear equations with two unknowns, $x$ and $y$, and many symbolic parameters, $a, b, c, d$. They look someting like: $\frac{1}{x}(1+x)^a (1-b)(cx+dy)=0$ ... - asked by jim (2 votes) ---------------------------- [Example in Help File does not evaluate as claimed]\url{http://mathematica.stackexchange.com/questions/60281/example-i n-help-file-does-not-evaluate-as-claimed} In the help file, under BellB, I read at 'Properties and Relations': "Sum can give results involving BellB ": Sum[k^n/k!, {k, 0, Infinity}] E BellB[n] but, in my version 10.0.1.0 it does not ... - asked by Wouter (2 votes) ---------------------------- [How to get the centroids of the ClusterComponents function]\url{http://mathematica.stackexchange.com/questions/60301/how-to-g et-the-centroids-of-the-clustercomponents-function} I use the ClusterComponent function to get the k-means clustering: Needs["HierarchicalClustering`"] cl = ClusteringComponents[data, 4, 1, DistanceFunction -> CorrelationDistance, Method -> ... - asked by user13675 (2 votes)
================================== Top new questions this week: ================================== [How many triangles are there?]\url{http://mathematica.stackexchange.com/questions/59350/how-many-t riangles-are-there} Some time ago I found a puzzle and it stopped my work until I solved it. One of the possible solutions: Let us sum upright and upside down triangles whose top lies in the $i$-th row. $$ ... - asked by ybeltukov (22 votes), answered by george2079 (20 votes) ---------------------------- [Composition a la Mondrian] \url{http://mathematica.stackexchange.com/questions/59620/composition-a-la-mondrian} I would like to paint something like this or,even better, like this I have tried colors = {Red, Blue, Yellow, White, Black}; cells = ConstantImage[RandomChoice[colors], #] & /@ ... - asked by eldo (21 votes), answered by Simon Woods (11 votes) ---------------------------- [Homotopy Visualization]\url{http://mathematica.stackexchange.com/questions/59463/hom otopy-visualization} I noticed that both the lower cased 'i' and the Apple logo are topologically equivalent to the disjoint union of two closed discs. I'd like to animate a homeomorphism from the left to the right, ... - asked by Tobi Lehman (18 votes), answered by Michael E2 (28 votes) ---------------------------- [Finding all paths of certain length between vertices in path graph, non-simple ones too]\url{http://mathematica.stackexchange.com/questions/59554/finding-all-p aths-of-certain-length-between-vertices-in-path-graph-non-simple-o} First I will tell you what my ultimate goal is, because maybe there's another way of doing it other than what I am trying. I need a list of all $(a_1, a_2, \ldots, a_N)$ tuples that satisfy certain ... - asked by luke (12 votes), answered by ybeltukov (7 votes) ---------------------------- [How to manipulate a circle in GeoGebra style?]\url{http://mathematica.stackexchange.com/questions/59726/how-to-man ipulate-a-circle-in-geogebra-style} I want to emulate the GeoGebra app. I want to get an effect like this in Mathematica. I don't know how to move whole circle without changing the radius of the circle. My sample code: ... - asked by mathe (11 votes), answered by Kuba (5 votes) ---------------------------- [Splitting strings into letter keys and integers]\url{http://mathematica.stackexchange.com/questions/59690/splittin g-strings-into-letter-keys-and-integers} I have strings of the following form: string = "ABC123DEFG456HI89UZXX1"; Letter keys of variable lengths are followed by (positive) integers. I want to get this transformation: {{"ABC", 123}, ... - asked by eldo (11 votes), answered by RunnyKine (10 votes) ---------------------------- [Mathematica isn't sure whether a sum of two positives is positive or not]\url{http://mathematica.stackexchange.com/questions/59589/mathematica-i snt-sure-whether-a-sum-of-two-positives-is-positive-or-not} Mathematica is not able to tell whether a summation of two positive expressions is positive or not. Which is very strange. My three symbolic arguments, $x$, $y$, and $z$, are all real numbers bounded ... - asked by jim (10 votes), answered by Jens (9 votes) ================================== Greatest hits from previous weeks: ================================== [Generating visually pleasing circle packs]\url{http://mathematica.stackexchange.com/questions/40334/generating- visually-pleasing-circle-packs} EDIT: I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you enjoyed as I did. I would like to generate a circle pack that mimics this: (don't pay attention on ... - asked by VividD (62 votes), answered by level1807 (39 votes) ---------------------------- [Finding real roots of negative numbers (for example, $\sqrt[3]{-8}$)]\url{http://mathematica.stackexchange.com/questions/3886/fi nding-real-roots-of-negative-numbers-for-example-sqrt3-8} Say I want to quickly calculate $\sqrt[3]{-8}$, to which the most obvious solution is $-2$. When I input $\sqrt[3]{-8}$ or Power[-8, 3^-1], Mathematica gives the result "$2 (-1)^{1/3}$". Not what I ... - asked by jtbandes (33 votes), answered by Brett Champion (13 votes) ================================== Can you answer these? ================================== [NIntegrate::ncvbr: How should we interpret and handle this error not mentioned in any documentation?]\url{http://mathematica.stackexchange.com/questions/59371/ni ntegratencvbr-how-should-we-interpret-and-handle-this-error-not-mentione d-i} I have some user-defined module describing my integrand which has to be computed numerically (it's much more complicated than this but bear with me): foo[x_?NumericQ, y_?NumericQ, z_?NumericQ] := ... - asked by Sarah (3 votes) ---------------------------- [How can I solve an equation where indexed variables get updated during iteration?]\url{http://mathematica.stackexchange.com/questions/59776/how-ca n-i-solve-an-equation-where-indexed-variables-get-updated-during-iterati on} I am trying to solve for a root for a certain equation, but some of the variables in this equation are indexed and get updated during iteration. The code that I am interested in is like the following: ... - asked by erickwy (1 vote) ---------------------------- [Generalize WASD Function First Person Viewing]\url{http://mathematica.stackexchange.com/questions/59655/generaliz e-wasd-function-first-person-viewing} How might I generalize the following WASD question such that it works with any Graphics3D object and includes q and e for z(up and down) movement? For example qweasd[gr_]. In addition, how might I ... - asked by Liam William (2 votes)
================================== Top new questions this week: ================================== [Finding length of intersection of two surfaces]\url{http://mathematica.stackexchange.com/questions/58768/finding- length-of-intersection-of-two-surfaces} I would like to know how we find the length of the intersection of two surfaces. For instance, in the following example,a surface intersects with a plane: How do we find the length of intersection ... - asked by user19522 (25 votes), answered by RunnyKine (18 votes) ---------------------------- [How to ask Mathematica to imitate Andy Warhol's pop-art painting?]\url{http://mathematica.stackexchange.com/questions/59132/how-to- ask-mathematica-to-imitate-andy-warhols-pop-art-painting} I tried to ask Mathematica to imitate Andy Warhol, let it convert a Marilyn Monroe's portrait looks like Warhol's world famous pop-art painting. However, the result shown below is far from ... - asked by Putterboy (24 votes), answered by Karsten 7. (16 votes) ---------------------------- [How to speed up my Project Euler code]\url{http://mathematica.stackexchange.com/questions/58751/how-to-speed -up-my-project-euler-code} The evaluation speed of Mathematica often depresses me. It did it again when I wrote a code to solve a Project Euler problem. https://projecteuler.net/problem=206 Here's my code: ClearAll[a]; a = ... - asked by Eric (17 votes), answered by Teake Nutma (13 votes) ---------------------------- [How do you turn off the Dashed graphics directive?]\url{http://mathematica.stackexchange.com/questions/58992/how-do -you-turn-off-the-dashed-graphics-directive} I'm looking at Graphics Directives but can't figure out a way to turn off the Dashed graphics directive. For example, given ListPlot[{Table[Sin[i], {i, 25}], Table[Cos[i], {i, 25}]}, Joined -> ... - asked by Andrew Cheong (16 votes), answered by m_goldberg (15 votes) ---------------------------- [symbolic integration error]\url{http://mathematica.stackexchange.com/questions/58940/symbolic-in tegration-error} I'm running Mathematica 10.0.0 and encountered a disturbing error in the symbolic integration of a rather simple function Integrate[(1 - x)*(1 + 2*x)^6/Sqrt[1 - x^2], {x, -1, 1}]/Pi The correct ... - asked by Carlo Beenakker (16 votes), answered by Artes (11 votes) ---------------------------- [How to generate a blank crossword sheet?]\url{http://mathematica.stackexchange.com/questions/59001/how-to-gen erate-a-blank-crossword-sheet} I attempted to generate a blank crossword sheet. My method is by combining the rows and columns as shown on the graph below. However, some of the across and down numbers then appeared out of place ... - asked by Putterboy (14 votes), answered by ybeltukov (17 votes) ---------------------------- [Where to see all Mathematica units]\url{http://mathematica.stackexchange.com/questions/58793/where-to-se e-all-mathematica-units} Is there a tutorial page that have all Mathematica units? I sometimes have hard time figuring out the correct unit spelling when using quantities - asked by Yituo (13 votes), answered by paw (17 votes) ================================== Greatest hits from previous weeks: ================================== [Finding unit tangent, normal, and binormal vectors for a given r(t)]\url{http://mathematica.stackexchange.com/questions/18598/finding-unit -tangent-normal-and-binormal-vectors-for-a-given-rt} For my Calc III class, I need to find $T(t), N(t)$, and $B(t)$ for $t=1, 2$, and $-1$, given $r(t)=\{t,t^2,t^3\}$. I've got Mathematica, but I've never used it before and I'm not sure how to coerce ... - asked by a98 (12 votes), answered by Artes (29 votes) ---------------------------- [Get a "step by step" evaluation in Mathematica]\url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (55 votes), answered by J.M. (47 votes) ================================== Can you answer these? ================================== [CUDALink Error: A CUDALink kernel timed out?]\url{http://mathematica.stackexchange.com/questions/58853/cudalink-err or-a-cudalink-kernel-timed-out} I'm following the CUDALink tutorial [ http://reference.wolfram.com/language/CUDALink/tutorial/Introduction.htm l ] and everything is going fine until I get to the part that calls CUDADot on the ... - asked by Edmund (2 votes) ---------------------------- [Using ParallelMap to run multiple Game of Life simulations simultaniously]\url{http://mathematica.stackexchange.com/questions/59224/us ing-parallelmap-to-run-multiple-game-of-life-simulations-simultaniously> ) My Assignment and Code As an exercise in Parallel computing I've been tasked with implementing Conway's GoL in a way such that at every iteration only a fraction of cells are updated. I'm then to run ... - asked by Jason Houtekamer (2 votes) ---------------------------- [How to syntax check that all instance of symbol must be contained in Subscript[]]\url{http://mathematica.stackexchange.com/questions/59202/how-t o-syntax-check-that-all-instance-of-symbol-must-be-contained-in-subscrip t} I have a function f[expr] that is only allowed to take an expression expr that is a polynomial in Subscript[x,_]. By this, I mean that expr can be a sum/difference of terms (up to other ... - asked by QuantumDot (2 votes)
================================== Top new questions this week: ================================== [Object separation from a 2.5D surface]\url{http://mathematica.stackexchange.com/questions/58269/object-se paration-from-a-2-5d-surface} I'm trying to identify the shape and the boundaries of objects. The data was generated with a laser scanner and represent the surface of an area in which many boulders lay on the ground and making up ... - asked by zeckra (18 votes), answered by shrx (3 votes) ---------------------------- [Site - Cell Correspondence in Voronoi Diagram obtained via VoronoiMesh]\url{http://mathematica.stackexchange.com/questions/58395/site- cell-correspondence-in-voronoi-diagram-obtained-via-voronoimesh} Consider the following: pts = RandomReal[4, {10, 2}]; vor = VoronoiMesh[pts, {{0, 4}, {0, 4}}]; Graphics[{GraphicsComplex[ MeshCoordinates[vor], {Thick, Blue, MeshCells[vor, 1], ... - asked by RunnyKine (12 votes), answered by ybeltukov (7 votes) ---------------------------- [How to create a neon light effect in Mathematica?]\url{http://mathematica.stackexchange.com/questions/58602/how- to-create-a-neon-light-effect-in-mathematica} I tried to use Glow to create a neon light effect on a torus object. The result shown on the left of the picture below looks quite different from the real one on the right. Is there a way to obtain a ... - asked by Putterboy (12 votes), answered by DaveStrider (26 votes) ---------------------------- [Find maximum value of interpolation function - obviously wrong result]\url{http://mathematica.stackexchange.com/questions/58244/find-maxim um-value-of-interpolation-function-obviously-wrong-result} Minimizing and maximizing interpolation function has already been asked and answered, see here for example. Yet, I observe a strange behaviour. Well, I can understand that the wrong guess of ... - asked by anderstood (11 votes), answered by Karsten 7. (12 votes) ---------------------------- [Set of integers not divisible by smaller set of primes]\url{http://mathematica.stackexchange.com/questions/58520/set-of-int egers-not-divisible-by-smaller-set-of-primes} Let $p_n$ be the sequence of prime numbers, and $s(x,n)=$ the set of integers less or equal than $x$ that are not divisible by $p_1,\dots,p_n.$ I can define it as follows: ... - asked by martin (10 votes), answered by Mr.Wizard (14 votes) ---------------------------- [Neumann boundary conditions in NDSolve over nontrivial region]\url{http://mathematica.stackexchange.com/questions/58412/neumann-bo undary-conditions-in-ndsolve-over-nontrivial-region} The problem I would like to solve involves diffusion in the following region reg = ImplicitRegion[-5 <= x <= 5 && -5 <= y <= 5 && x^2 + y^2 >= 1^2, {x, y}]; ... - asked by Greg P (10 votes), answered by user21 (9 votes) ---------------------------- [Is garbage collection broken in version 10.0.0?]\url{http://mathematica.stackexchange.com/questions/58375/is-garbag e-collection-broken-in-version-10-0-0} In version 10.0.0 under Windows I am observing the following behavior: Do[Module[{foo}, foo[x_] := 1; foo[0]], {10}] Names["foo$*"] {"foo$593", "foo$594", "foo$595", "foo$596", "foo$597", ... - asked by Mr.Wizard (9 votes) ================================== Greatest hits from previous weeks: ================================== [Can Mathematica do symbolic linear algebra?]\url{http://mathematica.stackexchange.com/questions/3242/can-mathe matica-do-symbolic-linear-algebra} For instance, is there some way I can say "let A and B be arbitrary real $m\times n$ and $k\times m$ matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ... - asked by nikie (24 votes), answered by helen (12 votes) ---------------------------- [How to force 2+2=5]\url{http://mathematica.stackexchange.com/questions/48929/how-to-forc e-22-5} I was looking at this question (writing a program such that 2 + 2 = 5) and tried to write something in Mathematica, but I couldn't get something to work without completely replacing Plus. Neither of ... - asked by Artefacto (4 votes), answered by halirutan (7 votes) ================================== Can you answer these? ================================== [SyntaxForm not correctly parsed by FrontEnd]\url{http://mathematica.stackexchange.com/questions/58531/syntaxfo rm-not-correctly-parsed-by-frontend} When using TagBox with SyntaxForm, I noticed sometimes it is not well parsed by the FrontEnd. Here is a minimal example. First input TagBox["f", "test", SyntaxForm -> "^"] // DisplayForm Then ... - asked by Yi Wang (1 vote) ---------------------------- [Segmentation of sunspots]\url{http://mathematica.stackexchange.com/questions/58673/segmenta tion-of-sunspots} I recently went for a walk with my camera and snapped a few pictures of the sun. The pictures didn't turn out too well, but this was to be expected without a telescope. I thought it might be a nice ... - asked by paw (6 votes) ---------------------------- [Implementation of Series function]\url{http://mathematica.stackexchange.com/questions/58343/implemen tation-of-series-function} I'm trying to evaluate the partial derivatives of some function F[x,y] at some point, i.e. Limit[Limit[D[F[x,y],{x,m},{y,n}],x->x0],y->y0] However, for higher derivatives I find that it fails ... - asked by Barefeg (2 votes)
================================== Top new questions this week: ================================== [Proving the hairy ball theorem using xAct]\url{http://mathematica.stackexchange.com/questions/57726/proving-the- hairy-ball-theorem-using-xact} I would to formally prove the hairy ball theorem in Mathematica, initially just for the $S^2$, and then see about generalizing. An approach I thought about to use the xAct package to define $S^2$ and ... - asked by Daniel Mahler (15 votes) ---------------------------- [How to understand the usage of Inner and Outer figuratively?]\url{http://mathematica.stackexchange.com/questions/57760/how -to-understand-the-usage-of-inner-and-outer-figuratively} Description: In Mathematica the functions like Thread, Inner, Outer etc. are very important and are used frequently. For the function Thread: ThreadUsage1: Thread[f[{a, b, c}]] {f[a], f[b], ... - asked by Tangshutao (15 votes), answered by Timothy Wofford (5 votes) ---------------------------- [Make MapIndexed listable]\url{http://mathematica.stackexchange.com/questions/57898/make-map indexed-listable} My goal is to apply MapIndexed to every element of a nested list without destroying the arithmetic operations within the elements. For example, let's start with this list: {a, {b, {c^d, {e + f g}}}} ... - asked by seismatica (14 votes), answered by Mr.Wizard (10 votes) ---------------------------- [Is it possible to insert new colour schemes into ColorData?]\url{http://mathematica.stackexchange.com/questions/57885/is-it- possible-to-insert-new-colour-schemes-into-colordata} Because of the standards in my field, for many plots I need to use (or at least end up using) rather narrowly defined colour schemes, and in particular the Matlab "Jet" scheme, which is well described ... - asked by episanty (12 votes), answered by Mr.Wizard (10 votes) ---------------------------- [How to combine one or more rotated graphics objects?]\url{http://mathematica.stackexchange.com/questions/57803/how-to-c ombine-one-or-more-rotated-graphics-objects} I wish to produce an image with more than one composite graphics objects which have been modified using Rotate. I feel this should not be difficult, but haven't yet found a solution. A simple example ... - asked by image_doctor (11 votes), answered by mfvonh (11 votes) ---------------------------- [What is the correct way to use specific rule for specific pattern match when parsing an expression?]\url{http://mathematica.stackexchange.com/questions/58010/what- is-the-correct-way-to-use-specific-rule-for-specific-pattern-match-when- par} update: Thanks for the answers below. But I noticed they do not handle the following special cases: lis=1 and lis=z , lis=1/z and lis=-z as these are also considered legal input as given in the ... - asked by Nasser (10 votes), answered by seismatica (6 votes) ---------------------------- [Map of United States as a 3D histogram]\url{http://mathematica.stackexchange.com/questions/57872/map-of- united-states-as-a-3d-histogram} By combining the state data from here and the extrusion code from here I have managed to make prisms of the various US states such as However, the extrusion method looses information about the ... - asked by sonright (10 votes), answered by Vitaliy Kaurov (11 votes) ================================== Greatest hits from previous weeks: ================================== [Finding all simple paths between two vertices in a graph]\url{http://mathematica.stackexchange.com/questions/25779/finding-all -simple-paths-between-two-vertices-in-a-graph} There are built-in methods to find a shortest path between two vertices in a graph, and the question on finding all shortest paths between two vertices has gathered quite a bit of attention. A path ... - asked by mrm (11 votes), answered by trybik (10 votes) ---------------------------- [Marking points of intersection between two curves]\url{http://mathematica.stackexchange.com/questions/10472/marking-po ints-of-intersection-between-two-curves} I'm trying to illustrate the solutions numerically and graphically for an equation such as Tan[x] == x. I think I did everything ok except I wanted to mark each intersection between Tan[x] and x. ... - asked by fiz (24 votes), answered by belisarius (31 votes) ================================== Can you answer these? ================================== [Error when using EquationTrekker]\url{http://mathematica.stackexchange.com/questions/58005/e rror-when-using-equationtrekker} I just got to know EquationTrakker because I need to do phase graphs for my classes. When I load it << EquationTrekker` everything works fine with no errors. However when I try to use an ... - asked by Geo (2 votes) ---------------------------- [How to solve for exponents in an infinite product?]\url{http://mathematica.stackexchange.com/questions/57930/how-to-s olve-for-exponents-in-an-infinite-product} Say I have a power series, $f(x,y) \in 1 + x\mathbb{Z}[[x,y]]$ Then it admits a unique expansion $$f(x,y) = \prod_{i=1}^\infty \prod_{j=0}^\infty (1 - x^i y^j)^{n_{i,j}}$$ for some integers, $i, ... - asked by Vivek Shende (2 votes) ---------------------------- [Exporting a compiled function for later use]\url{http://mathematica.stackexchange.com/questions/58108/exporting-a-c ompiled-function-for-later-use} I compiled a function then used it in NMinimize. The computation took 19 seconds. Then, I exported this compiled function and restarted MMA and imported this compiled function into my notebook. This ... - asked by yashar (5 votes)
================================== Top new questions this week: ================================== [Is this 30% slowdown in Mathematica 10 due to DownValues lookup time?]\url{http://mathematica.stackexchange.com/questions/57301/is-this-30- slowdown-in-mathematica-10-due-to-downvalues-lookup-time} Running several numerical self-programmed packages I realized already some time ago that Mathematica 10 needed between 20 and 40% more time. I did already report this of course with a simple example ... - asked by Rolf Mertig (26 votes) ---------------------------- [2D random walk within a bounded area]\url{http://mathematica.stackexchange.com/questions/57561/2d-random-wa lk-within-a-bounded-area} I want to simulate a random walk on two dimension in a bounded area such as a square or circle. I am thinking of using If statement to define a boundary. Is there a better way to define a bounded ... - asked by yashar (20 votes), answered by Pickett (21 votes) ---------------------------- ["Indexing" a vector]\url{http://mathematica.stackexchange.com/questions/57613/indexing-a -vector} I need to "index" a vector according to the first occurence of its distinct elements. I have written index[list_] := Module[{x = list, p}, p = Flatten /@ Map[Position[x, #] &, ... - asked by eldo (13 votes), answered by kguler (18 votes) ---------------------------- [Convert spectral distribution to RGB color]\url{http://mathematica.stackexchange.com/questions/57389/convert-spe ctral-distribution-to-rgb-color} Presume I have a spectrum as a function of wavelength (an example being the blackbody spectrum): I want to convert that to a single RGB color to display on-screen, i.e. the "color" of that object ... - asked by Guillochon (13 votes), answered by Sjoerd C. de Vries (11 votes) ---------------------------- [Why does Mathematica simplify $x/x\to1$?]\url{http://mathematica.stackexchange.com/questions/57489/why-do es-mathematica-simplify-x-x-to1} If I enter x/x, I get 1. Such behavior leads to this: Simplify[D[Sqrt[x^2], x, x]] 0 The same would be even if I use Together instead of Simplify. One could then think that $\sqrt{x^2}$ is ... - asked by Ruslan (11 votes), answered by Jens (5 votes) ---------------------------- [Manipulate crashes after running 4 minutes]\url{http://mathematica.stackexchange.com/questions/57247/manipulat e-crashes-after-running-4-minutes} The following code generates the familiar 3D-plot: Manipulate[ Plot3D[Sin[x a] - Cos[y ], {x, -10, 10}, {y, -10, 10}, ColorFunction -> "TemperatureMap"], {a, -2, 2, 0.1}] However ... - asked by MathLind (10 votes), answered by Szabolcs (2 votes) ---------------------------- [Incompatible InterpolatingFunction between V9 (and earlier) and V10]\url{http://mathematica.stackexchange.com/questions/57608/incompatible- interpolatingfunction-between-v9-and-earlier-and-v10} I am encountering compatibility issues when loading DumpSave(d) definitions in V10 that have been created with earlier versions. V10 appears to be unable to digest `InterpolatingFunction from earlier ... - asked by Markus Roellig (10 votes), answered by Mr.Wizard (4 votes) ================================== Greatest hits from previous weeks: ================================== [Marking points of intersection between two curves]\url{http://mathematica.stackexchange.com/questions/10472/marking-po ints-of-intersection-between-two-curves} I'm trying to illustrate the solutions numerically and graphically for an equation such as Tan[x] == x. I think I did everything ok except I wanted to mark each intersection between Tan[x] and x. ... - asked by fiz (24 votes), answered by belisarius (31 votes) ---------------------------- [How to find all the local minima/maxima in a range]\url{http://mathematica.stackexchange.com/questions/5575/how-to-find- all-the-local-minima-maxima-in-a-range} I want to find : all local maxima in range all local minima in range >From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ... - asked by Margus (38 votes), answered by Daniel Lichtblau (40 votes) ================================== Can you answer these? ================================== [Is it possible to Compile the function with string argument?]\url{http://mathematica.stackexchange.com/questions/57355/is-it-p ossible-to-compile-the-function-with-string-argument} As we can see from the Compile documentation, the typical arguments for Compile should be Integer, Real, Complex and True | False: Is it possible to use a String as argument type for Compile? May ... - asked by Rom38 (2 votes) ---------------------------- [Functional-Style Fixed-Length Queue Object?]\url{http://mathematica.stackexchange.com/questions/57539/functiona l-style-fixed-length-queue-object} Following up on question Side-effecting an array in an association? and @Mr.Wizard's answer in there, I'm modernizing and tweaking Daniel Lichtblau's efficient queues and ran into a little roadblock. ... - asked by Reb.Cabin (2 votes) ---------------------------- [Adding an unused column creates an error in JoinAcross]\url{http://mathematica.stackexchange.com/questions/57345/adding -an-unused-column-creates-an-error-in-joinacross} I'd been having trouble using JoinAcross on two datasets. After going through the answers to my original question and fixing my code, I find I'm now having a problem that I think is being caused by ... - asked by Mitchell Kaplan (2 votes)
================================== Top new questions this week: ================================== [Incompatible Changes since Mathematica Version 7?]\url{http://mathematica.stackexchange.com/questions/56728/incompatible-c hanges-since-mathematica-version-7} There is documentation of the incompatible changes made to Mathematica with each major release: Incompatible Changes since Mathematica Version 1 Unfortunately that documentation simply stopped ... - asked by Mr.Wizard (22 votes), answered by Mr.Wizard (22 votes) ---------------------------- [How to make a stereogram in Mathematica?]\url{http://mathematica.stackexchange.com/questions/57034/how- to-make-a-stereogram-in-mathematica} Given a background and a pattern jpg files, is there a quick and easy way to produce a stereogram by using Mathematica? The following picture was produced from Photoshop, spent about half an hour. ... - asked by user16069 (15 votes), answered by Simon Woods (9 votes) ---------------------------- [Combining images with CUDA]\url{http://mathematica.stackexchange.com/questions/56786/combining-im ages-with-cuda} 2nd Edition: To make it a bit more clear, and to summarize the discussion in comments. I have a small image, like this one: InsertImage = DensityPlot[Sqrt[1 - x^2 - y^2], {x, -1, 1}, {y, -1, 1}, ... - asked by Alexey Bobrick (13 votes), answered by Simon Woods (10 votes) ---------------------------- [How to change element color in Periodic Table?]\url{http://mathematica.stackexchange.com/questions/57133/how-to-cha nge-element-color-in-periodic-table} The command ColorData["Atoms", "Panel"] generates a periodic table. As I don't want to reinvent the wheel, I asked myself how to change the color of each cell in the periodic table, (hydrogen -> ... - asked by Zhozer (12 votes), answered by belisarius (14 votes) ---------------------------- [Apply an image as a texture to text]\url{http://mathematica.stackexchange.com/questions/56719/apply-an-ima ge-as-a-texture-to-text} I have the following equation eq = Sum[x^2, {x, 0, 10}] and an image image = Import["http://creativity103.com/collections/Graphic/rainbowbars.jpg"]. How might I output a transparent version of the ... - asked by Liam William (11 votes), answered by Simon Woods (16 votes) ---------------------------- [Dataset: get number of levels and elements]\url{http://mathematica.stackexchange.com/questions/56983/dataset- get-number-of-levels-and-elements} The summary box for Dataset objects shows the number of levels and elements at the bottom. How can we get these values programmatically? For example, "4 levels, 350 elements" in the Planets ... - asked by Szabolcs (10 votes), answered by WReach (7 votes) ---------------------------- [PlotLegends -> "Expressions" not working when Plot given one function]\url{http://mathematica.stackexchange.com/questions/56829/plotlege nds-expressions-not-working-when-plot-given-one-function} I don't get a legend when I use the option PlotLegends -> "Expressions" when the first argument to Plot is a single function. It works OK when I give Plot a list of functions. Test cases: ... - asked by mathe (10 votes), answered by rcollyer (8 votes) ================================== Greatest hits from previous weeks: ================================== [Finding unit tangent, normal, and binormal vectors for a given r(t)]\url{http://mathematica.stackexchange.com/questions/18598/finding-unit -tangent-normal-and-binormal-vectors-for-a-given-rt} For my Calc III class, I need to find $T(t), N(t)$, and $B(t)$ for $t=1, 2$, and $-1$, given $r(t)=\{t,t^2,t^3\}$. I've got Mathematica, but I've never used it before and I'm not sure how to coerce ... - asked by a98 (12 votes), answered by Artes (29 votes) ---------------------------- [Finding the centroid of the area between two curves]\url{http://mathematica.stackexchange.com/questions/17170/finding-th e-centroid-of-the-area-between-two-curves} When I have an area bounded by curves, is there a built-in way to find the center of the area? Or do I have to plot it first and then use ComponentMeasurements on it? For example: the area under $y= ... - asked by a3f (10 votes), answered by george2079 (3 votes) ================================== Can you answer these? ================================== [Plotting a transformed region only works with integer inputs]\url{http://mathematica.stackexchange.com/questions/57112/plotting-a -transformed-region-only-works-with-integer-inputs} I can't figure out why the following code only works with integers. r1 = TransformedRegion[Cuboid[{-1, -1, -1}, {1, 1, 1}], TranslationTransform[{0, 1, 0}]] RegionPlot3D[r1] DiscretizeRegion[r1] ... - asked by jeff (5 votes) ---------------------------- [Symbolic integration of elliptic functions]\url{http://mathematica.stackexchange.com/questions/57024/symboli c-integration-of-elliptic-functions} Is there some clever way to integrate products of elliptic functions $\wp(z;g_2,g_3)$ or $\zeta(z;g_2,g_3)$ in Mathematica? Mathematica seems to be able to integrate functions like ... - asked by TheTwistedSector (3 votes) ---------------------------- [Version 10 cannot print properly?]\url{http://mathematica.stackexchange.com/questions/57182/version -10-cannot-print-properly} I have two problems with printing in version 10. First, I can't print correctly with a setting of printing scale For example, I have some plots in a notebook, Grid@Table[ Plot[Sin[x], {x, 0, 2 ... - asked by xslittlegrass (2 votes)
================================== Top new questions this week: ================================== [Numerically solving Helmholtz equation in 2D for arbitrary shapes]\url{http://mathematica.stackexchange.com/questions/56305/numericall y-solving-helmholtz-equation-in-2d-for-arbitrary-shapes} I would like to solve the Helmholtz equation with dirichlet boundary conditions in 2 dimensions for an arbitrary shape. (for a qualitative comparison of the eigenstates to periodic orbits in the ... - asked by Julian S. (25 votes), answered by Mark McClure (20 votes) ---------------------------- [V10's Operator Forms - what are they good for?]\url{http://mathematica.stackexchange.com/questions/56504/v10s-operato r-forms-what-are-they-good-for} V10 introduces an operator form for several functions perhaps primarily due to their role in queries as part of introducing data science functionality. At first pass it seems a lot of effort to add ... - asked by Ronald Monson (22 votes), answered by Simon Woods (24 votes) ---------------------------- [Why is Query so much slower than Part?]\url{http://mathematica.stackexchange.com/questions/56609/why-is-quer y-so-much-slower-than-part} Time for another of these(1),(2) as yet another new-in-10 function appears to have poor performance compared to older alternatives. This time: Query appears to be orders of magnitude slower than Part ... - asked by Mr.Wizard (15 votes), answered by m_goldberg (8 votes) ---------------------------- [BitShiftRight produces incorrect results in Version 10]\url{http://mathematica.stackexchange.com/questions/56241/bitshiftright- produces-incorrect-results-in-version-10} With Mathematica 10 for Mac, BitShiftRight works properly on lists of up to 100000 numbers, but appears to give incorrect results when threaded over lists of 100001 or more: v1 = Table[i, {i, 1, ... - asked by DBM (14 votes), answered by Mr.Wizard (9 votes) ---------------------------- [Speed of curated data calls in Version 10]\url{http://mathematica.stackexchange.com/questions/56172/speed-of-curat ed-data-calls-in-version-10} Curated datasets underwent a significant overhaul in version 10, primarily in the way content is delivered in the form of Objects and Entities. Additionally, it appears that this change in content ... - asked by bobthechemist (14 votes), answered by Nick Lariviere (13 votes) ---------------------------- [the winding number for the circle map (Arnold tongue)]\url{http://mathematica.stackexchange.com/questions/56499/the-windi ng-number-for-the-circle-map-arnold-tongue} I want to do an iterative calculation: f[n_, a_, b_] := Nest[# + a - b Sin[2 Pi #] &, 0, n]/n; If I use i use the machine precision, it maybe produce a great error,for example: N@f[500, 1/2, ... - asked by Chenminqi (12 votes), answered by heropup (10 votes) ---------------------------- [Speed up adding Poisson noise to an image]\url{http://mathematica.stackexchange.com/questions/56180/speed-up-ad ding-poisson-noise-to-an-image} I'm simulating some images corrupted with Poisson noise, but I'm encountering a few problems with performance. According to the documentation on ImageEffect, one can add Poisson noise according to the ... - asked by blochwave (11 votes), answered by blochwave (16 votes) ================================== Greatest hits from previous weeks: ================================== [How can I add drop shadows and specular highlights to 2D graphics?]\url{http://mathematica.stackexchange.com/questions/43186/how-can -i-add-drop-shadows-and-specular-highlights-to-2d-graphics} I thought I'd share some code in the form of a self-answered question, but other answers are of course welcome. Drop shadows are a familiar visual effect, giving the impression of a graphical element ... - asked by Simon Woods (31 votes), answered by Simon Woods (35 votes) ---------------------------- [Resources for beautiful Mathematica Stylesheets]\url{http://mathematica.stackexchange.com/questions/5846/resour ces-for-beautiful-mathematica-stylesheets} When the Wolfram Demonstrations were introduced and the Documentation-Center was redesigned, I remember it was the first time I thought someone had put some effort into creating a beautiful ... - asked by halirutan (81 votes), answered by rm -rf (41 votes) ================================== Can you answer these? ================================== [DatabaseLink Example for DB2 and Mathematica]\url{http://mathematica.stackexchange.com/questions/56283/datab aselink-example-for-db2-and-mathematica} could someone please point me to good example on how to make a JDBC connection to an IBM DB2 database? - asked by Rick QI (1 vote) ---------------------------- [Precision problem while evaluating RegionMember or Element in V10]\url{http://mathematica.stackexchange.com/questions/56402/precision-pro blem-while-evaluating-regionmember-or-element-in-v10} I'll try to give you a background on where the problem occured. The problem itself is defined near the end of the post. I'm running a sort of a simulation of a particle in a box. I finally got my ... - asked by Daroslav (3 votes) ---------------------------- [Workarounds for a possible bug in the linearity of FourierTransform]\url{http://mathematica.stackexchange.com/questions/56237/ workarounds-for-a-possible-bug-in-the-linearity-of-fouriertransform} This is somewhat similar to this question, except the problem I am encountering is to do with Fourier transforms of scalar multiples of functions and their derivatives. I wish to input ... - asked by Oliver Lunt (2 votes)
================================== Top new questions this week: ================================== [Best practice of passing a large number of parameters to functions]\url{http://mathematica.stackexchange.com/questions/55833/best-pr actice-of-passing-a-large-number-of-parameters-to-functions} I have a number of functions which all take a large number of parameters. I am wondering which is the best practice of passing these parameters to those functions. I could of course simply specify the ... - asked by Uwe Thummel (16 votes), answered by Mr.Wizard (12 votes) ---------------------------- [Is there a way to recreate the typical Red/Blue-Postereffect using Mathematica?]\url{http://mathematica.stackexchange.com/questions/55684/is-t here-a-way-to-recreate-the-typical-red-blue-postereffect-using-mathemati ca} I think nearly all of us have at least once seen an image like this: So I wondered whether it is possible to recreate this effect using Mathematica because it seems like it wouldn't need that many ... - asked by Levix (15 votes), answered by kale (14 votes) ---------------------------- [How can I mend this broken heart?]\url{http://mathematica.stackexchange.com/questions/55905/how-can-i- mend-this-broken-heart} Try to evaluate the following code: ContourPlot3D[(x^2 + 9/4 y^2 + z^2 - 1)^3 == x^2 z^3 + 9/80 y^2 z^3, {x, -6/5, 6/5}, {y, -6/5, 6/5}, {z, -6/5, 3/2}, Mesh -> None, Boxed -> False, ... - asked by LCFactorization (13 votes), answered by Rahul Narain (18 votes) ---------------------------- [Geographic background containing both outlines and contours: how?]\url{http://mathematica.stackexchange.com/questions/55900/geographic-b ackground-containing-both-outlines-and-contours-how} I would like to create a map which will show lakes and rivers together with elevation contours and contour labels. What is the simplest way to do this with GeoGraphics in version 10? The solution I ... - asked by Szabolcs (11 votes), answered by WReach (11 votes) ---------------------------- [What is the natural way of using Dataset to get a FittedModel?]\url{http://mathematica.stackexchange.com/questions/56110/what -is-the-natural-way-of-using-dataset-to-get-a-fittedmodel} The new Dataset in Mathematica 10 is a great addition to the language, potentially reducing the convenience gap with R. Given this, I would like to understand what the equivalent simple or natural ... - asked by Simplex (10 votes), answered by WReach (5 votes) ---------------------------- [Testing Credit Usage in Wolfram Programming Cloud]\url{http://mathematica.stackexchange.com/questions/55970/testing-cre dit-usage-in-wolfram-programming-cloud} I currently have a free WPC account, which I am using for testing purposes. Amongst other things, I want to find out more about how the credit system works, in particular how many credits are used, ... - asked by Analyst (9 votes), answered by Analyst (5 votes) ---------------------------- [Possible bug in Dynamic]\url{http://mathematica.stackexchange.com/questions/55855/possible- bug-in-dynamic} The code below crashes the Mathematica kernel in version 10 (not in V9) every time I run it on Windows and on Mac OS. I've sent it to WRI, but was told that they could not reproduce the crash. Does ... - asked by nikie (9 votes), answered by Michael E2 (4 votes) ================================== Greatest hits from previous weeks: ================================== [Even Fibonacci numbers]\url{http://mathematica.stackexchange.com/questions/37266/even-fibo nacci-numbers} Today, I found the Euler Project. Problem #2 is Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, ... - asked by Tangshutao (22 votes), answered by rcollyer (29 votes) ---------------------------- [Implementing efficient multiple undo]\url{http://mathematica.stackexchange.com/questions/1953/implementing- efficient-multiple-undo} At the time this question was asked, version 10 was not out yet. The Front End of Mathematica 10 does have multiple undo, see the answer by John Fultz. The Mathematica Front End's built-in Undo ... - asked by Rojo (111 votes), answered by John Fultz (30 votes) ================================== Can you answer these? ================================== [Result of Integrate depends on order of integration although the domain is rectangular]\url{http://mathematica.stackexchange.com/questions/55868/resul t-of-integrate-depends-on-order-of-integration-although-the-domain-is-re cta} The following: Mass/(2 J) Integrate[(-2Rotation(r^2(r-Mass)(1-3Cos[\[Theta]]^2) - Rotation^2(r Cos[\[Theta]]^2(3-Cos[\[Theta]]^2)-Mass(1+Cos[\[Theta]]^2)(2-Cos[\[Theta]]^2))))/(r^2+Rotation^2Cos[\[Theta]]^2)^2 - asked by auxsvr (2 votes) ---------------------------- [PlotMarkers problem in ErrorListPlot, Mathematica 10]\url{http://mathematica.stackexchange.com/questions/56132/plotmarkers-pr oblem-in-errorlistplot-mathematica-10} I recently upgraded to Mathematica 10, very excited about the multiple undo function of course. However I very quickly noticed that if I specify a setting for PlotMarkers in the ErrorListPlot ... - asked by nate (2 votes) ---------------------------- [Unique CellID in-between notebooks]\url{http://mathematica.stackexchange.com/questions/55968/unique- cellid-in-between-notebooks} Documentation says that CellID is guaranteed to be unique for a given notebook. I've noticed that CellID are fairly high numbers and although probabilistically speaking the odds of coincidence are ... - asked by Ranza (2 votes)
================================== Top new questions this week: ================================== [DeleteDuplicatesBy is not performing as I'd hoped. Am I missing something?]\url{http://mathematica.stackexchange.com/questions/55294/delete duplicatesby-is-not-performing-as-id-hoped-am-i-missing-something} Deja vu: a new-in-v10 function should provide a better solution to an old problem, but my enthusiasm is curbed when I run timings. This time the function is DeleteDuplicatesBy and while its ... - asked by Mr.Wizard (18 votes), answered by Jacob Akkerboom (23 votes) ---------------------------- [Mathematica 10 Notebook Fonts Look Bad]\url{http://mathematica.stackexchange.com/questions/55071/mathematica-1 0-notebook-fonts-look-bad} I've upgraded my home installation of Mathematica from version 9 to 10 today on a Windows 8.1 machine, and I'm getting a weird font issue - the fonts are not anti-aliased, and look unbalanced and ... - asked by Gleno (17 votes), answered by Tetsuo Ichii (17 votes) ---------------------------- [Mathematica 10 funny bug / Easter egg?]\url{http://mathematica.stackexchange.com/questions/55081/mathematica- 10-funny-bug-easter-egg} I have no idea what is happening here. I'm using Mathematica 10. I mistyped "FriendNetwork" as "FriendsNetwork" and got a weird result: The option "FriendsNetwork" is not even listed in the help ... - asked by Space monkey (17 votes), answered by Pickett (20 votes) ---------------------------- [Why does ImportString["1c", "Table"] eat the letter c?]\url{http://mathematica.stackexchange.com/questions/55245/why-does-impor tstring1c-table-eat-the-letter-c} I have some whitespace-separated matrix data that I read with Import[..., "Table"]. The data contained mixed strings and numbers (the strings are for row and column names). I noticed this weird ... - asked by Szabolcs (14 votes), answered by Szabolcs (16 votes) ---------------------------- [HoldForm doesn't hold form]\url{http://mathematica.stackexchange.com/questions/55506/holdform-doe snt-hold-form} In Mathematica version 10, HoldForm no longer produces the same results as in version 8 (edit: I only have versions 10 and 8 installed, so can't compare to version 9 directly). Here are some examples ... - asked by Jens (12 votes), answered by Simon Woods (4 votes) ---------------------------- [Why does WRI not provide symbolic solution(s) to Heat equation?]\url{http://mathematica.stackexchange.com/questions/55546/why-doe s-wri-not-provide-symbolic-solutions-to-heat-equation} Why does WRI not provide symbolic solution(s) to Heat equation? or more generally, Green functions to known PDEs I am interested in variations of the heat equation: I understand that Mathematica ... - asked by chris (12 votes) ---------------------------- [BarLegend changes in Version 10]\url{http://mathematica.stackexchange.com/questions/55150/barlegend-chan ges-in-version-10} Apparently, BarLegend in version 10 displays tick legends in scientific notation when they are smaller in magnitude than 0.01. For instance, BarLegend[{"Rainbow", {-.015, .015}}, LabelStyle -> ... - asked by bbgodfrey (11 votes), answered by kguler (8 votes) ================================== Greatest hits from previous weeks: ================================== [When running Mathematica from a Linux terminal, how can I prevent a script from terminating upon logout?]\url{http://mathematica.stackexchange.com/questions/42838/when-runn ing-mathematica-from-a-linux-terminal-how-can-i-prevent-a-script-from} I am running Mathematica on a remote Linux cluster, by the terminal, using the math command. (I do not have access to a terminal GUI. For example, when I type the command mathematica, I get this ... - asked by Andrew (11 votes), answered by shrx (2 votes) ---------------------------- [Even Fibonacci numbers]\url{http://mathematica.stackexchange.com/questions/37266/even-fibo nacci-numbers} Today, I found the Euler Project. Problem #2 is Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, ... - asked by Tangshutao (22 votes), answered by rcollyer (29 votes) ================================== Can you answer these? ================================== [LibraryLink: is WolframLibraryData libData persistent?]\url{http://mathematica.stackexchange.com/questions/54962/libra rylink-is-wolframlibrarydata-libdata-persistent} I am writing some C++ code that I want to call both through LibraryLink and independently from Mathematica. Thus it must be compatible with LibraryLink but not depend on it. When calling it from ... - asked by Szabolcs (3 votes) ---------------------------- [Issuing user-defined messages takes a long time (Message is slow)]\url{http://mathematica.stackexchange.com/questions/55069/issuing-use r-defined-messages-takes-a-long-time-message-is-slow} Issuing messages takes a very long time in version 9 and version 10. Can others reproduce this? Is there a fix? Update: This is slow only when using the front end, but not when running the kernel ... - asked by Szabolcs (6 votes) ---------------------------- [Report: IgnoringInactive: a bug?]\url{http://mathematica.stackexchange.com/questions/55462/report-ignor inginactive-a-bug} Just to report. IgnoringInactiveshould work with Cases. In agreement with the things written at the Documentation Center this: Cases[{Cos[a], Inactive[Cos][b]}, IgnoringInactive[Cos[x_]]] works ... - asked by Alexei Boulbitch (9 votes)
================================== Top new questions this week: ================================== [How to make use of Associations?]\url{http://mathematica.stackexchange.com/questions/52393/how -to-make-use-of-associations} I have been curious about it for long. Now that Mathematica 10 arrives, I think it's time to ask the question: How the new Association data structure would be used to improve Mathematica programming? ... - asked by Yi Wang (38 votes), answered by Leonid Shifrin (36 votes) ---------------------------- [PositionIndex is horribly slow]\url{http://mathematica.stackexchange.com/questions/54853/positioninde x-is-horribly-slow} I do not know how best to formulate this as a question but the new PositionIndex is horribly slow. Using Szabolcs's clever GatherBy inversion we can implement our own function for comparison: ... - asked by Mr.Wizard (25 votes), answered by Taliesin Beynon (15 votes) ---------------------------- [Is it possible to define new PlotTheme?]\url{http://mathematica.stackexchange.com/questions/54545/is-it- possible-to-define-new-plottheme} In version 10 one can define, say, $PlotTheme = "Scientific" Which changes the appearance of all plots. This is fantastic because on the one hand, I can have nice plots very easily and globally ... - asked by Yi Wang (19 votes), answered by Mr.Wizard (12 votes) ---------------------------- [What information is sent to Wolfram Research when loading or working with Mathematica?]\url{http://mathematica.stackexchange.com/questions/54921/what -information-is-sent-to-wolfram-research-when-loading-or-working-with-ma them} Recently I am told that information unknown to the user is sent to Wolfram Servers. Is there any truth behind it ? I was told that more than just an IP address of the user is sent to them and that ... - asked by nathan (18 votes) ---------------------------- [How to disable the small pop-up windows when mouse is over a Mathematica command in V10?]\url{http://mathematica.stackexchange.com/questions/52406/how-to-disab le-the-small-pop-up-windows-when-mouse-is-over-a-mathematica-command} In version 10, when the mouse is over a Mathematica command, a small pop-up window comes up that one can click on for help on the command. Is there an option to disable this feature? Screen shot: ... - asked by Nasser (17 votes), answered by Martin John Hadley (17 votes) ---------------------------- [What's the difference between Inactive and HoldForm?]\url{http://mathematica.stackexchange.com/questions/54556/whats-t he-difference-between-inactive-and-holdform} In version 10, Mathematica not only added Inactive / Activate but also highlighted this change in the "New in 10" page (in Core Language Enhancements). Thus, I suppose it should be something useful. ... - asked by Yi Wang (14 votes), answered by mfvonh (11 votes) ---------------------------- [Mma 10: Half the parallel power (Mac Pro)?]\url{http://mathematica.stackexchange.com/questions/54553/mma-10-half -the-parallel-power-mac-pro} Here is a comparison of the parallel kernels launched under Mathematica under v9 and v10, on the same identical current 2014 R2-D2 Mac Pro ... Under v9.01 $ProcessorCount 12 Issuing: ... - asked by wolfies (14 votes), answered by Szabolcs (10 votes) ================================== Greatest hits from previous weeks: ================================== [Calling MATLAB from Mathematica]\url{http://mathematica.stackexchange.com/questions/10231/calli ng-matlab-from-mathematica} How can I call MATLAB functions directly from Mathematica and transfer data/variables between the two systems? - asked by siva82kb (33 votes), answered by Szabolcs (43 votes) ---------------------------- [What is the best Mathematica tutorial for young people?]\url{http://mathematica.stackexchange.com/questions/733/what-is-the -best-mathematica-tutorial-for-young-people} As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ... - asked by noisy (33 votes), answered by Vitaliy Kaurov (17 votes) ================================== Can you answer these? ================================== [possible bug in Mathematica TeXForm? Generating \left\left]\url{http://mathematica.stackexchange.com/questions/54857/possib le-bug-in-mathematica-texform-generating-left-left} I asked about this in the TeX chat. It seems Mathematica generate invalid Latex in this example. ClearAll[y,x]; ode = D[y[x], x] - (y[x]^2 + 1)/(Abs[y[x] + (1 + y[x])^(1/2)]*(1 + x)^(3/2)); ... - asked by Nasser (2 votes) ---------------------------- [How to get a uniformly distributed list of points from a B-spline function]\url{http://mathematica.stackexchange.com/questions/54841/how-to-g et-a-uniformly-distributed-list-of-points-from-a-b-spline-function} I created a spline function from a list of points and made a plot as follows: list2 = {{3.93453, -0.623168}, {3.79708, -0.187231}, {3.72835, 0.0307369}, {3.65963, 0.248705}, {3.5909, 0.466673}, ... - asked by Kaisey (1 vote) ---------------------------- [Autocomplete of non-global functions]\url{http://mathematica.stackexchange.com/questions/54827/autocom plete-of-non-global-functions} In Mathematica 9 and 10 they added autocompletion. Out of the box this works great, but when I set the CellContext to "Notebook" instead of the default "Global" (following this) it no longer ... - asked by Anders (7 votes)
================================== Top new questions this week: ================================== [Quick way to use conditioned patterns when defining multi-argument function?]\url{http://mathematica.stackexchange.com/questions/52057/quick-w ay-to-use-conditioned-patterns-when-defining-multi-argument-function} I have a simple function that is supposed to only accept numeric values (i.e. complex/real numbers and constant symbols e.g. Pi, E). $$f(a,b,c)=a+b+c$$ Edit: I should have chosen a less simple ... - asked by seismatica (13 votes), answered by Mr.Wizard (14 votes) ---------------------------- [ToExpression fails with long nested string expressions]\url{http://mathematica.stackexchange.com/questions/52097/toexp ression-fails-with-long-nested-string-expressions} Consider the following conversion from String to Mathematica Expression: n = 10; ToExpression[Table["{", {n}] <> Table["}", {n}]] {{{{{{{{{{}}}}}}}}}} Everything is fine. However, when ... - asked by shrx (10 votes), answered by Mr.Wizard (7 votes) ---------------------------- [The mysterious gap inside Grid]\url{http://mathematica.stackexchange.com/questions/52185/the-mysterio us-gap-inside-grid} There's this gap inside Grid which I cannot seem to remove. Perhaps someone knows how. blocks = Table[{Graphics[{Darker@Green, Rectangle[{0, 0}, {1000, 200}]}]}, {i, 6}] myGrid = Grid[blocks, ... - asked by Jonie (8 votes), answered by Mr.Wizard (3 votes) ---------------------------- [Why are functions called first-class objects in Mathematica?]\url{http://mathematica.stackexchange.com/questions/52064/why- are-functions-called-first-class-objects-in-mathematica} I've heard lots of people say a function is a first-class object in Mathematica. "Everything is an expression, including function." "There is no distinction between functions and data." Having read ... - asked by Eric (8 votes), answered by nikie (12 votes) ---------------------------- [Dual graph of an arbitrary (planar) graph]\url{http://mathematica.stackexchange.com/questions/52056/dual-graph- of-an-arbitrary-planar-graph} Every planar graph has a dual. How can I obtain it with Mathematica? I know that GraphData provides the DualGraph property for its named graphs, but I have found no method for computing the dual of ... - asked by user16311 (7 votes), answered by Grisha Kirilin (9 votes) ---------------------------- [256 Shades of Grey]\url{http://mathematica.stackexchange.com/questions/52099/256-shades-o f-grey} I noticed that the following line, Image[Table[x, {y, 1, 250}, {x, 30/256, 40/256, 0.02/256}], Magnification -> 1] results in the following image: In the preceding image, there are 10 ... - asked by DumpsterDoofus (7 votes), answered by joojaa (5 votes) ---------------------------- [Implementing key-value associations in Mathematica 9 with inexact numbers for keys]\url{http://mathematica.stackexchange.com/questions/51997/implementing -key-value-associations-in-mathematica-9-with-inexact-numbers-for-ke} I'm not sure of what type of problem my issue falls into, so I haven't been able to search forums with any success. If this has already been solved then my apologies! Essentially I'm trying to set a ... - asked by Andrew Stewart (7 votes), answered by Michael E2 (2 votes) ================================== Greatest hits from previous weeks: ================================== [Is Mathematica an Implementation of the Wolfram Language?]\url{http://mathematica.stackexchange.com/questions/37557/is-math ematica-an-implementation-of-the-wolfram-language} I am trying to figure out what the announcement of the Wolfram Language means for Mathematica. Is Mathematica an implementation of the Wolfram Language, or is it something else? - asked by Eric Brown (43 votes), answered by Joel Klein (18 votes) ---------------------------- [Calling MATLAB from Mathematica]\url{http://mathematica.stackexchange.com/questions/10231/calli ng-matlab-from-mathematica} How can I call MATLAB functions directly from Mathematica and transfer data/variables between the two systems? - asked by siva82kb (33 votes), answered by Szabolcs (43 votes) ================================== Can you answer these? ================================== [Compiled NormFunction]\url{http://mathematica.stackexchange.com/questions/52202/comp iled-normfunction} I would like to use a user-defined NormFunction with NDSolve, e.g., NormFunction -> (Norm[Take[#, 2], \[Infinity]] &) which says that the infinity norm should be used on the first two state ... - asked by jaclea (1 vote) ---------------------------- [Calculating probabilities symbolically]\url{http://mathematica.stackexchange.com/questions/51994/calc ulating-probabilities-symbolically} Is there a way to solve for statistical quantities analytically/symbolically in Mathematica? example 1: Lets say that I want to do a calculation that requires Bayes theorem. I know p(a), p(b) and ... - asked by kamula (5 votes) ---------------------------- [How to implement nested With as a single construct using functional programming (Fold)?]\url{http://mathematica.stackexchange.com/questions/51976/how-to-im plement-nested-with-as-a-single-construct-using-functional-programming} It is possible to define my own With construct where each local constant can depend on the previous defined local constants? I wish to replace something like this With[{m=10}, With[{h=1/m}, ... - asked by unlikely (1 vote)
================================== Top new questions this week: ================================== [Fitting points to tilted, off-center ellipse]\url{http://mathematica.stackexchange.com/questions/51491/fitting-p oints-to-tilted-off-center-ellipse} I have 24 x-y points that are supposed to form an ellipse. ... - asked by seismatica (15 votes), answered by ubpdqn (17 votes) ---------------------------- [Combining BarChart and Grid - IPCC style]\url{http://mathematica.stackexchange.com/questions/51708/combining-b archart-and-grid-ipcc-style} I would like to combine a plot with a table. Something like this famous plot/table from IPCC: So after reading Combining graphics & lists / tables I tried an approach using Grid. Pretty ... - asked by gogoolplex (12 votes), answered by Oska (4 votes) ---------------------------- [How to implement Donald Knuth's up-arrow notation]\url{http://mathematica.stackexchange.com/questions/51657/how-to-i mplement-donald-knuths-up-arrow-notation} How does one enter very large numbers in up-arrow notation? Up-arrow notation was created by Donald Knuth to write very large numbers in it iterated exponentiation form, for example 63 = 6^6^6. - asked by user4401 (12 votes), answered by Szabolcs (20 votes) ---------------------------- [Is there a way to increase the smoothness of a cylinder?]\url{http://mathematica.stackexchange.com/questions/51565/is-ther e-a-way-to-increase-the-smoothness-of-a-cylinder} I am using Cylinder to produce wide flat disks (in Mathematica 8). This works just fine except that the circular base of such a cylinder turns out to be really just a 40-gon which is simply too coarse ... - asked by Burkard Polster (11 votes), answered by Mr.Wizard (13 votes) ---------------------------- [Efficient way to build a certain quadratic matrix]\url{http://mathematica.stackexchange.com/questions/51798/efficient- way-to-build-a-certain-quadratic-matrix} For odd n I'm looking for a short and swift way to construct with (f.e.) n = 3 n = 11 n=1111 - asked by eldo (9 votes), answered by RunnyKine (8 votes) ---------------------------- [Finding maximum or minimum of implicit functions]\url{http://mathematica.stackexchange.com/questions/51679/finding -maximum-or-minimum-of-implicit-functions} is there any built in function that can be used to find maximum or minimum of implicit functions? For example, if we have the equation $$x^2 + y^2 = (2 x^2 + 2 y^2 - x)^2,$$ then we can visualize the ... - asked by Algohi (7 votes), answered by Kuba (15 votes) ---------------------------- [How can a power of 0 or 1 be replaced?]\url{http://mathematica.stackexchange.com/questions/51585/how-can -a-power-of-0-or-1-be-replaced} Consider this given example for ReplaceAll 1 + x^2 + x^4 /. x^p_ -> f[p] This returns 1+f[2]+f[4] - works good (!). But if you choose In[175]:= 1 +x+ x^2 + x^4 /. x^p_ -> f[p] Out[175]= ... - asked by Sumit (7 votes), answered by Daniel Lichtblau (6 votes) ================================== Greatest hits from previous weeks: ================================== [Resources for beautiful Mathematica Stylesheets]\url{http://mathematica.stackexchange.com/questions/5846/resour ces-for-beautiful-mathematica-stylesheets} When the Wolfram Demonstrations were introduced and the Documentation-Center was redesigned, I remember it was the first time I thought someone had put some effort into creating a beautiful ... - asked by halirutan (80 votes), answered by rm -rf (40 votes) ---------------------------- [Get a "step by step" evaluation in Mathematica]\url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (53 votes), answered by J.M. (44 votes) ================================== Can you answer these? ================================== [What's a non-trivial Mathematica program involving conscious choice of stack vs. queue data structure?]\url{http://mathematica.stackexchange.com/questions/51862/whats- a-non-trivial-mathematica-program-involving-conscious-choice-of-stack-vs > } In a typical computer science algorithms course, much attention is given to the discussion of queues vs. stacks as a data structure programmers need to consciously choose from to achieve algorithmic ... - asked by Problemaniac (1 vote) ---------------------------- [Import Excel data forcing links (ie workbooks) to be updated]\url{http://mathematica.stackexchange.com/questions/51873/import-ex cel-data-forcing-links-ie-workbooks-to-be-updated} We have noticed importing data from an Excel spreadsheet doesnt update links. The problem with this is if you import a spreadsheet that comprises of linked workbooks data and those workbooks have ... - asked by WolframFan (3 votes) ---------------------------- [Smooth out contour in RegionPlot/ContourPlot]\url{http://mathematica.stackexchange.com/questions/ 51518/smooth-out-contour-in-regionplot-contourplot} I would like to smooth out the jagged edges in the outermost contours in the following plot: I have data of values as a function of variables (x,y) in the form data = ... - asked by Philo (1 vote) --- Subscribe to more Stack Exchange newsletters: <http://stackexchange.com/newsletters> ---
================================== Top new questions this week: ================================== [Longest path in 0/1 matrix]\url{http://mathematica.stackexchange.com/questions/51247/longest-pa th-in-0-1-matrix} I have a matrix of 0's and 1's forming a number of disjoint paths: I would like to find the lengths of the paths, and from that "spectrum," the longest length (in the above example: 27, ... - asked by Joseph O'Rourke (25 votes), answered by rm -rf (24 votes) ---------------------------- [Visualization: elliptical insights into data sets]\url{http://mathematica.stackexchange.com/questions/51163/visualizati on-elliptical-insights-into-data-sets} I was recently reading the following paper on visualization techniques using ellipses to gain statistical insights. Elliptical visualization for looking at correlations has briefly been touched on ... - asked by Pam (12 votes), answered by Pam (2 votes) ---------------------------- [What is the relationship between Mathematica and Wolfram Desktop?]\url{http://mathematica.stackexchange.com/questions/51372/what-is- the-relationship-between-mathematica-and-wolfram-desktop} I'm confused about the differences among various Wolfram products. In particular what is the relationship among Mathematica, Mathematica Online, Wolfram Programming Cloud, and Wolfram Desktop? Are ... - asked by raxacoricofallapatorius (12 votes), answered by mfvonh (8 votes) ---------------------------- [Find intersection of pairs of straight lines]\url{http://mathematica.stackexchange.com/questions/51391/find-inters ection-of-pairs-of-straight-lines} I have a list of 24 points, in which 2 consecutive points (1st and 2nd, 3rd and 4th, ...) are supposed to form a line. p1={{243.8, 77.}, {467.4, 12.}, {291.8, 130.}, {476., 210.5}, {103.2, 327.}, ... - asked by seismatica (6 votes), answered by eldo (9 votes) ---------------------------- [What is wrong about Abs[x]-a? Is it a bug?]\url{http://mathematica.stackexchange.com/questions/51118/what-is-wron g-about-absx-a-is-it-a-bug} Why is the Out[74] not {1 - a, {x -> -1}}? Maximize[{Sqrt[x^2] - a, -1 <= x <= 1}, x] {1 - a, {x -> -1}} - asked by fptan (6 votes), answered by RiemannZeta (4 votes) ---------------------------- [Find the smallest positive integer that satisfies a certain condition]\url{http://mathematica.stackexchange.com/questions/51086/find-th e-smallest-positive-integer-that-satisfies-a-certain-condition} I know Mathematica is really powerful when it comes to functional operations like applying a list of tasks to a list of variables. Sometimes I feel like it isn't the most powerful tool when it comes ... - asked by cartonn (6 votes), answered by mfvonh (9 votes) ---------------------------- [Why am I getting wildly incorrect results from FirstPassageTimeDistribution with inexact transition matrix?]\url{http://mathematica.stackexchange.com/questions/51018/why-am-i- getting-wildly-incorrect-results-from-firstpassagetimedistribution-with> ) Working on some large systems using DiscreteMarkovProcess, I changed the transition matrix to machine precision vs using exact values, which sped things up handily. The only problem was for edge ... - asked by rasher (6 votes), answered by Bhuvanesh (4 votes) ================================== Greatest hits from previous weeks: ================================== [How many Christmas gifts?]\url{http://mathematica.stackexchange.com/questions/39338/how-many-c hristmas-gifts} This question is based on the old song, The Twelve Days of Christmas In a comment made on a recent question, Yves Klett remarked, "no seasonal questions this year?" This reminded me of one I solved ... - asked by m_goldberg (18 votes), answered by rm -rf (23 votes) ---------------------------- [Generating visually pleasing circle packs]\url{http://mathematica.stackexchange.com/questions/40334/generating- visually-pleasing-circle-packs} EDIT: I want to thank you all guys for this unexpected intellectual and artistic journey. Hope you enjoyed as I did. I would like to generate a circle pack that mimics this: (don't pay attention on ... - asked by VividD (60 votes), answered by level1807 (36 votes) ================================== Can you answer these? ================================== [Solve set of non-linear equations with least-squares-fitting - constrain results?]\url{http://mathematica.stackexchange.com/questions/51274/solve-se t-of-non-linear-equations-with-least-squares-fitting-constrain-results} I'm trying to solve a set of functions to determine the material properties from a set of measurement values. (To set up this method I just want to fit my model with some already calculated data). My ... - asked by dummesschaf (1 vote) ---------------------------- [what is the best package/way to insert Mathematica code in latex docs?]\url{http://mathematica.stackexchange.com/questions/51215/what-is-the -best-package-way-to-insert-mathematica-code-in-latex-docs} I know that this question is not about strictly mathematica issue, but I think that in this site should be many pepople that use latex to distribute mathematica source code/examples. If the moderators ... - asked by Mika Ike (1 vote) ---------------------------- [How to force the compilation language to be C++ (not C) in CreateExecutable or CreateLibrary]\url{http://mathematica.stackexchange.com/questions/51012/how -to-force-the-compilation-language-to-be-c-not-c-in-createexecutable-or- c} I'm trying to speed up a section of a Mathematica 9.0.1 notebook by performing some calculations in C++ with the Cilk Plus and Threading Building Blocks tools available for the Intel C++ 14.0 compiler ... - asked by user15996 (4 votes)
================================== Top new questions this week: ================================== [Smooth Peter de Jong attractor]\url{http://mathematica.stackexchange.com/questions/50839/smooth- peter-de-jong-attractor} Today I was playing with Peter de Jong attractor. At the bottom of the page I've linked there are beautiful examples like: My attempts are not so great: It is around 10^5 points. For more than ... - asked by Kuba (17 votes), answered by KennyColnago (15 votes) ---------------------------- [How would you efficiently implement BinListsBy?]\url{http://mathematica.stackexchange.com/questions/50559/how-w ould-you-efficiently-implement-binlistsby} Let's say I have a list like this: data = {{21, "Alice"}, {27, "Bob"}, {22, "Charles"}, {34, "Dora"}, {75, "Eliza"}} containing ages and names of persons. What I would like is a list of e.g. ... - asked by nikie (9 votes), answered by Mr.Wizard (8 votes) ---------------------------- [Mathematica outliner's capabilities]\url{http://mathematica.stackexchange.com/questions/50637/math ematica-outliners-capabilities} As my notebooks get larger, I often try to organize them with titles/subtitles etc, structuring them as an outliner (http://en.wikipedia.org/wiki/Outliner) This also helps me as I try to structure a ... - asked by alessandro (8 votes), answered by Mike Honeychurch (7 votes) ---------------------------- [Control BarLegend size]\url{http://mathematica.stackexchange.com/questions/50913/control-barl egend-size} I want to plot a big 2D array of experiment data. I need plot axes and tick labels as well as a bar legend using BarLegend: ArrayPlot[ Array[RandomInteger[100] &, {100, 100}], PlotLegends -> ... - asked by Johu (6 votes), answered by Johu (6 votes) ---------------------------- [Skip header lines on import]\url{http://mathematica.stackexchange.com/questions/50718/skip-heade r-lines-on-import} When importing a data file what are the comment symbols for Mathematica? That is, given a file like this blabla bulbul 1 2 6 54 7 ... .. what symbol do I have to put in front of header lines so ... - asked by user3683367 (6 votes), answered by george2079 (7 votes) ---------------------------- [How can I list all the 'countries 4000 km far from current location'?]\url{http://mathematica.stackexchange.com/questions/50786/how-ca n-i-list-all-the-countries-4000-km-far-from-current-location} A friend said to me on Facebook that she is 4000km away. So I want to try to guess where she is. How can I find which countries are a given distance from my current location? - asked by Boti (5 votes), answered by Oska (14 votes) ---------------------------- [Can I automatically stop operation that is too slow?]\url{http://mathematica.stackexchange.com/questions/50746/can-i-autom atically-stop-operation-that-is-too-slow} I need to write code like this: Do operation 1, but if it takes more that 5 seconds then stop it and do operation 2. Is it possible to do this somehow without manual interruption? - asked by user15933 (5 votes), answered by Nasser (8 votes) ================================== Greatest hits from previous weeks: ================================== [What is the fastest way to extract a substring from a huge string?]\url{http://mathematica.stackexchange.com/questions/44175/what-is-t he-fastest-way-to-extract-a-substring-from-a-huge-string} I develop an algorithm to find the most common substrings of a given length n up to a certain distance l in front of a pattern p in a huge sequence S. E.g. I want to find the most common hexamers ... - asked by g3kk0 (11 votes), answered by Leonid Shifrin (9 votes) ---------------------------- [When running Mathematica from a Linux terminal, how can I prevent a script from terminating upon logout?]\url{http://mathematica.stackexchange.com/questions/42838/when-runn ing-mathematica-from-a-linux-terminal-how-can-i-prevent-a-script-from} I am running Mathematica on a remote Linux cluster, by the terminal, using the math command. (I do not have access to a terminal GUI. For example, when I type the command mathematica, I get this ... - asked by Andrew (10 votes), answered by shrx (2 votes) ================================== Can you answer these? ================================== [Understanding performance: graph connected components]\url{http://mathematica.stackexchange.com/questions/50523/unders tanding-performance-graph-connected-components} I need to analyze directed graphs with 10M edges, 1M vertices, and 300K strongly connected components, so that the largest one contains 400K vertices. I read some explanations of Leonid Shifrin here, ... - asked by Grisha Kirilin (3 votes) ---------------------------- [Natural boundary conditions variational methods]\url{http://mathematica.stackexchange.com/questions/50526/natural-b oundary-conditions-variational-methods} I am working on a problem of the calculus of variations. From the Variational Methods package, I can very conveniently use EulerEquations to get stationarity conditions in the form of Euler-Lagrange ... - asked by Marijnn (1 vote) ---------------------------- [How to find a scaling parameter in matrix inversion process by MMA?]\url{http://mathematica.stackexchange.com/questions/50660/how-to-find- a-scaling-parameter-in-matrix-inversion-process-by-mma} I simply would like to find the inverse of a given matrix $A$ by the iterative method $X_{k+1}=X_k(2I-AX_k)$ using $X_0=\frac{1}{\sigma_{max}^2}A^*$. An example is as follows SeedRandom[123]; m = n = ... - asked by Fazlollah Soleymani (1 vote)
================================== Top new questions this week: ================================== [Making a Mathematica package manager?]\url{http://mathematica.stackexchange.com/questions/49111/making-a -mathematica-package-manager} I'd like to get a serious discussion started about a package manager. This has come up elsewhere, and many people have implemented their own solutions. It would be nice to have a standardized way to ... - asked by mfvonh (10 votes), answered by mfvonh (7 votes) ---------------------------- [Graph from binary matrix (not adjacency) respecting the original matrix positions]\url{http://mathematica.stackexchange.com/questions/50363/graph-f rom-binary-matrix-not-adjacency-respecting-the-original-matrix-position> ) I have a binary matrix. My objective is to connect every close (without "jump") elements with value equal to 1, but I must keep the point positions, just like it's shown at the image. Can somebody ... - asked by Jazz (9 votes), answered by Oska (11 votes) ---------------------------- [Using Mathematica to make a graphics array of circles]\url{http://mathematica.stackexchange.com/questions/49176/using-mat hematica-to-make-a-graphics-array-of-circles} I need to make .svg file that contains an array of black circles that all have radii of 5 units ad are evenly spaced apart from each other 32 units. The difficulty in creating this design is the ... - asked by Sebastian Freeman (9 votes), answered by halirutan (3 votes) ---------------------------- [CSS Selectors for Symbolic XML]\url{http://mathematica.stackexchange.com/questions/49052/css-selectors -for-symbolic-xml} Symbolic XML is a convenient way of managing XML in Mathematica, at least for casual use or small tasks. Here and elsewhere you can find examples of XML handling in Mathematica, including XSLT/XPath ... - asked by Fallible (8 votes), answered by Fallible (12 votes) ---------------------------- [Complement of multisets]\url{http://mathematica.stackexchange.com/questions/49068/complem ent-of-multisets} Given lists $a$ and $b$, which represent multisets, how can I compute the complement $a\setminus b$? I'd like to construct a function xunion that returns the symmetric difference of multisets. For ... - asked by Leon Lampret (8 votes), answered by rasher (8 votes) ---------------------------- [Thread over uneven (ragged) expressions with full functionality?]\url{http://mathematica.stackexchange.com/questions/49359/th read-over-uneven-ragged-expressions-with-full-functionality} There are a number of questions on this site about "threading" including several relating to uneven (ragged) lists. However, none that I could find deal with the full functionality of Thread but ... - asked by Mr.Wizard (7 votes), answered by mfvonh (5 votes) ---------------------------- [Hatched Filling for ListPlot]\url{http://mathematica.stackexchange.com/questions/49202/hatched- filling-for-listplot} I am plotting to data curves using ListLinePlot. I like the look of Filling, but this is going to be printed, so I want something both black and white friendly, but giving more definition and ... - asked by ThomasH (7 votes), answered by ThomasH (4 votes) ================================== Greatest hits from previous weeks: ================================== [Finding real roots of negative numbers (for example, $\sqrt[3]{-8}$)]\url{http://mathematica.stackexchange.com/questions/3886/fi nding-real-roots-of-negative-numbers-for-example-sqrt3-8} Say I want to quickly calculate $\sqrt[3]{-8}$, to which the most obvious solution is $-2$. When I input $\sqrt[3]{-8}$ or Power[-8, 3^-1], Mathematica gives the result "$2 (-1)^{1/3}$". Not what I ... - asked by jtbandes (31 votes), answered by Brett Champion (10 votes) ---------------------------- [Is it possible to export the equations from Mathematica to MATLAB?]\url{http://mathematica.stackexchange.com/questions/14035/is-it-pos sible-to-export-the-equations-from-mathematica-to-matlab} Is it possible to export the output expressions from Mathematica computations (e.g., equations) in valid MATLAB syntax? - asked by Seyhmus Gungoren (14 votes), answered by rm -rf (20 votes) ================================== Can you answer these? ================================== [Relative performance of the Julia language]\url{http://mathematica.stackexchange.com/questions/50391/relative -performance-of-the-julia-language} I was just reviewing the Mathematica benchmark code linked from the Julia language home page http://julialang.org/. The stated goal of the benchmarks is to test the performance of specific algorithms, ... - asked by TheDoctor (2 votes) ---------------------------- [Help wanted in evaluating an integral]\url{http://mathematica.stackexchange.com/questions/49319/help-wan ted-in-evaluating-an-integral} Trying to evaluate an integral. To be specific, I'm trying to find the expectation value of $x^2$ for the ground state of hydrogen. Here is the code I used: FullSimplify[ Integrate[x^2/(Pi*a^3) ... - asked by Sam (1 vote) ---------------------------- [Tooltip over a picture & creating complex forms]\url{http://mathematica.stackexchange.com/questions/49235/tooltip-ove r-a-picture-creating-complex-forms} I have some picture like the one seen below. Now, I'm trying to create some tooltip with some descriptions when moving with the mouse over a body part e.g. "this is the head", "This is the left arm" ... - asked by holistic (1 vote)
================================== Top new questions this week: ================================== [Is this the most effective and efficient programming style for prototyping (a ray tracer) in Mathematica?]\url{http://mathematica.stackexchange.com/questions/48675/is-t his-the-most-effective-and-efficient-programming-style-for-prototyping-a -ra} I am trying out Mathematica as a prototyping tool. As an initial exercise I have put together a brute force ray tracer, with a view to using Mathematica's built in probability distribution functions ... - asked by jrp (22 votes) ---------------------------- [Negative probability?]\url{http://mathematica.stackexchange.com/questions/48814/nega tive-probability} I am trying to get the sum of the squares of seven random variables, all uniformly distributed. This is what I tried. Probability[ a^2 + b^2 + c^2 + d^2 + e^2 + f^2 + g^2 < 1, {a, b, c, d, e, ... - asked by bobbym (18 votes), answered by m_goldberg (12 votes) ---------------------------- [Aligning two lists]\url{http://mathematica.stackexchange.com/questions/48908/aligning-tw o-lists} I have two lists, L1 and L2, each with a key and some data. Let us say the key is a person's name, a string, and the data follows. (To respond to rasher's query:) Let us also assume the lists are ... - asked by Joseph O'Rourke (8 votes), answered by Mr.Wizard (4 votes) ---------------------------- [Any way I can solve this integral?]\url{http://mathematica.stackexchange.com/questions/48766/any-way -i-can-solve-this-integral} So, Mathematica can't solve it. Any workaround? \begin{equation*} \int_0^\pi \frac{1}{\sin\left(\frac{\theta}{2}\right)^\beta + 1} \mathrm{d}\theta \end{equation*} The code is: ... - asked by user1883163 (7 votes), answered by Vitaliy Kaurov (10 votes) ---------------------------- [Speed up ContourPlot3D]\url{http://mathematica.stackexchange.com/questions/48773/spe ed-up-contourplot3d} I have two issues with the following code. (1) It executes too slowly. If I use "Speed" instead of "Quality" for PerformanceGoal, I get the speed but an undesirable delay in proper rendering of the ... - asked by Stephen (7 votes), answered by Kuba (4 votes) ---------------------------- [Binarize turning image completely black?]\url{http://mathematica.stackexchange.com/questions/48683/binarize-t urning-image-completely-black} Running Binarize (or EdgeDetect) on a filled black and white image is resulting in an all black image. The image has the following color distribution (with most images points falling in either a ... - asked by Peeter Joot (7 votes), answered by Jens (14 votes) ---------------------------- [Why does Equal["string", False] not evaluate to False?]\url{http://mathematica.stackexchange.com/questions/48851/why-does-e qualstring-false-not-evaluate-to-false} Why does Equal["string", False] not evaluate to False? I would have thought Mathematica could prove that these two things are not equal. - asked by Fructose (6 votes), answered by eldo (5 votes) ================================== Greatest hits from previous weeks: ================================== [What Mathematica book to buy?]\url{http://mathematica.stackexchange.com/questions/5059/what-mathemat ica-book-to-buy} I have used Mathematica for several years but at a pretty low level - piecing together built-in function inefficiently and fearing the sight of # and &'s when I see others use them (I never do). I ... - asked by BeauGeste (28 votes), answered by David (42 votes) ---------------------------- [How to find all the local minima/maxima in a range]\url{http://mathematica.stackexchange.com/questions/5575/how-to-find- all-the-local-minima-maxima-in-a-range} I want to find : all local maxima in range all local minima in range >From those points I can interpolate and combine functions upper and lower boundary. What I am really interested in, is the ... - asked by Margus (35 votes), answered by Daniel Lichtblau (37 votes) ================================== Can you answer these? ================================== [Suspend computation so it can be resumed even after the PC is rebooted]\url{http://mathematica.stackexchange.com/questions/48793/suspend- computation-so-it-can-be-resumed-even-after-the-pc-is-rebooted} Sometimes a computation takes a long time. But when I sleep in the night, I want to shutdown my PC. Next morning when I wake, I want to start Mathematica and resume the computation. If you are ... - asked by user565739 (3 votes) ---------------------------- [Simulating a system of nonlinear ODEs?]\url{http://mathematica.stackexchange.com/questions/49004/simulating- a-system-of-nonlinear-odes} I was trying to simulate a system of ODEs on Mathematica in an effort to try to understand how to muck around with Mathematica but for some reason the following lines of code do not yield any results; ... - asked by Gadha007 (2 votes) ---------------------------- [Documentation build failed with Workbench]\url{http://mathematica.stackexchange.com/questions/48958/documen tation-build-failed-with-workbench} I'm starting to use Wolfram Workbench 2 to develop a Mathematica package. For the first time I tried "Documentation - Build" under the "Application Tools" but got fatal errors: BUILD FAILED ... - asked by Chris K (2 votes) ---
================================== Top new questions this week: ================================== [Why won't Parallelize speed up my code?] <http://mathematica.stackexchange.com/questions/48295/why-wont-parallelize-speed-up-my-code> What reasons are there that can cause parallelized Mathematica code not to run with full performance? - asked by Szabolcs (18 votes), answered by Szabolcs (26 votes) ---------------------------- [High-quality RegionPlot3D for logical combinations of predicates]\url{http://mathematica.stackexchange.com/questions/48486/high-q uality-regionplot3d-for-logical-combinations-of-predicates} Unlike RegionPlot, RegionPlot3D copes poorly with logical combinations of predicates (&&, ||), which should result in sharp edges in the region to be plotted. Instead, these edges are usually ... - asked by Rahul Narain (11 votes), answered by Simon Woods (10 votes) ---------------------------- [Correct way to integrate a certain function]\url{http://mathematica.stackexchange.com/questions/48437/correct- way-to-integrate-a-certain-function} I want to integrate $$ \int_{0}^{2\pi} dt_1 \frac{a + b*\cos(t_1 - t_2)}{c + d*\cos(t_1 - t_2)} $$ where $a, b, c, d, t_2$ are real numbers and $c + d > 0$ & $0 \leq t_2 \leq 2\pi$. I used ... - asked by vik (9 votes), answered by Michael E2 (4 votes) ---------------------------- [How do I get Mathematica to return a function call unevaluated?]\url{http://mathematica.stackexchange.com/questions/48349/how- do-i-get-mathematica-to-return-a-function-call-unevaluated} How do I get Mathematica to return a function call (conditionally) unevaluated? I expect this may use the slightly-mysterious Hold function. As a toy example, suppose I want to define AlgebraicQ such ... - asked by Charles (9 votes), answered by Szabolcs (9 votes) ---------------------------- [Why is plot legend unsafe?]\url{http://mathematica.stackexchange.com/questions/48291/why-is-pl ot-legend-unsafe} Every time I open a notebook contains a legend, I get the message warning that it's not safe. Why does this happen and how to fix it? - asked by xslittlegrass (9 votes), answered by Szabolcs (12 votes) ---------------------------- [Faster way to compute the distance from a point to a surface in 3D]\url{http://mathematica.stackexchange.com/questions/48565/faster-way-to- compute-the-distance-from-a-point-to-a-surface-in-3d} I am trying to compute the shortest distance between a point and a triangle in 3D distance[point_, {p1_, p2_, p3_}] := Module[{p, s, t, sol}, p = s*p1 + (1 - s)*(t*p2 + (1 - t)*p3); ... - asked by tintin (8 votes), answered by RunnyKine (15 votes) ---------------------------- [Does the syntax coloring I see indicate a real problem?]\url{http://mathematica.stackexchange.com/questions/48432/does-the -syntax-coloring-i-see-indicate-a-real-problem} I need a behaviour provided by: x = 2; Block[{x = HoldForm[x]}, x] x FrontEnd marks this syntax as not quite correct. It has not caused me any troubles so far so my question is: could it ... - asked by Kuba (8 votes), answered by halirutan (6 votes) ================================== Greatest hits from previous weeks: ================================== [How many Christmas gifts?]\url{http://mathematica.stackexchange.com/questions/39338/how-many-c hristmas-gifts} This question is based on the old song, The Twelve Days of Christmas In a comment made on a recent question, Yves Klett remarked, "no seasonal questions this year?" This reminded me of one I solved ... - asked by m_goldberg (18 votes), answered by rm -rf (23 votes) ---------------------------- [How to generate a random snowflake]\url{http://mathematica.stackexchange.com/questions/39361/how-to- generate-a-random-snowflake} 'Tis the season... And it's about time I posed my first question on Mathematica Stack Exchange. So, here's an holiday quest for you Graphics (and P-Chem?) gurus. What is your best code for generating ... - asked by Peltio (87 votes), answered by Silvia (117 votes) ================================== Can you answer these? ================================== [Diagonalization in parallel]\url{http://mathematica.stackexchange.com/questions/48416/diagonal ization-in-parallel} I would like to diagonalize one unitary non-sparse matrix of size 12870 with complex number entries (not symbols, this is really a numerical problem). Is is possible to make eigensystem run in ... - asked by lagoa (1 vote) ---------------------------- [Package FiniteFields]\url{http://mathematica.stackexchange.com/questions/48379/pack age-finitefields} In a Mathematica session, I evaluate: Needs["FiniteFields`"]; fld = GF[2]; Now, for example, I'd like to compute $a^3+a^5$ for $a \in{Z_2}$. The result I'd like to have is $0$, because in $Z_2$, ... - asked by user14545 (1 vote) ---------------------------- [When to use indexed variables]\url{http://mathematica.stackexchange.com/questions/48602/when-to -use-indexed-variables} Still learning the fundamentals of the language I would like to ask you what advantages there might be in writing something like: a[1] = 2; a[2] = 4; a[3] = "x"; It seems to me that it is always ... - asked by eldo (3 votes)
================================== Top new questions this week: ================================== [How can I get the color of overlapping disks to be equal in any order?]\url{http://mathematica.stackexchange.com/questions/47809/how-can-i- get-the-color-of-overlapping-disks-to-be-equal-in-any-order} When Graphics is used, necessarily the objects come in order. This affects which ones obscure others. When Opacity is not 1, it also affects the color. I would like the color of overlaps to depend ... - asked by Russ Lyons (19 votes), answered by Mr.Wizard (9 votes) ---------------------------- [Bug in mathematica analytic integration?]\url{http://mathematica.stackexchange.com/questions/48113/bug- in-mathematica-analytic-integration} I found Mathematica provides me a wrong answer for a relatively simple analytically solvable integral: Integrate[Exp[-I\[Theta]]/(1+b Cos[\[Theta]]),{\[Theta],0,2\[Pi]} Assumptions -> b < 1 && b ... - asked by user14456 (14 votes), answered by Artes (14 votes) ---------------------------- [how to make a pie chart using custom image]\url{http://mathematica.stackexchange.com/questions/48078/how-to-make -a-pie-chart-using-custom-image} Can we make a pie chart using a costumed picture? For example, in representing the 0.1 cent, I would like to use this image and cut a piece out, and make a clickable pie chart. Any suggestions are ... - asked by xslittlegrass (13 votes), answered by belisarius (20 votes) ---------------------------- [Undocumented use of Integrate: Integrating over regions]\url{http://mathematica.stackexchange.com/questions/48166/undocumen ted-use-of-integrate-integrating-over-regions} I have come across a few questions asking about integrating over regions. And while the answers are impressive there should be a better more consistent way. So my question is, are there ways, ... - asked by RunnyKine (12 votes), answered by RunnyKine (15 votes) ---------------------------- [Rebuild a polygon so it doesn't self intersect]\url{http://mathematica.stackexchange.com/questions/48091/rebuild -a-polygon-so-it-doesnt-self-intersect} If you consider the following Polygon: coor = {{6, 0}, {6, 1}, {4, 0}, {5, 2}}; (* and coor = {{7, 2}, {7, 1}, {5, 2}, {6, 1}} *) pol = Polygon@coor; Graphics@pol I would like to know if there is ... - asked by Oska (10 votes), answered by Rahul Narain (10 votes) ---------------------------- [Exp is slower for some number ranges]\url{http://mathematica.stackexchange.com/questions/47982/exp-is-slo wer-for-some-number-ranges} I get a hit on performance with the Exp function depending on the range of my inputs. for example, with: w1 = RandomComplex[-20000 I, {10000000}]; Exp[w1]; // Timing w2 = RandomComplex[-20 I, ... - asked by user173743 (10 votes) ---------------------------- [Determine frequency of oscillations]\url{http://mathematica.stackexchange.com/questions/47917/dete rmine-frequency-of-oscillations} I am wondering how I could determine the frequency of oscillations of a differential model equation? How could I find the frequency from this example given in Mathematica Documentation: s = ... - asked by tarhawk (10 votes), answered by Daniel Lichtblau (15 votes) ================================== Greatest hits from previous weeks: ================================== [Generate a Unit Circle Trigonometry]\url{http://mathematica.stackexchange.com/questions/2456/gener ate-a-unit-circle-trigonometry} Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data : - asked by 500 (13 votes), answered by Mark McClure (27 votes) ---------------------------- [How do I plot coordinates (latitude and longitude pairs) on a geographic map?]\url{http://mathematica.stackexchange.com/questions/2076/how-do-i-plot -coordinates-latitude-and-longitude-pairs-on-a-geographic-map} I'm attempting for the first time to create a map within Mathematica. In particular, I would like to take an output of points and plot them according to their lat/long values over a geographic map. I ... - asked by Peter House (37 votes), answered by kguler (24 votes) ================================== Can you answer these? ================================== [How can I make sure that 3D plots have the exact same orientation and viewpoint?]\url{http://mathematica.stackexchange.com/questions/47996/how-ca n-i-make-sure-that-3d-plots-have-the-exact-same-orientation-and-viewpoin t} First off, I apologize that I can't come up with a simpler working example, but I only seem to have this problem with the larger examples. I am trying to make animations, using functions like the ... - asked by Jason B (5 votes) ---------------------------- [Why setting PlotPoints make my 3d contour plot broken?]\url{http://mathematica.stackexchange.com/questions/47924/why-setti ng-plotpoints-make-my-3d-contour-plot-broken} I'm trying to make a iso surface plot from some data using ContourPlot3d. My data is a 3 dimension data with form like {{x,y,f[x,y]},...}. I first make this data into 4d by rotating it along the x ... - asked by xslittlegrass (2 votes) ---------------------------- [What's the difference between variables with and without a subscript?]\url{http://mathematica.stackexchange.com/questions/48174/whats- the-difference-between-variables-with-and-without-a-subscript} If I input $x = a + b$, the $x$, $a$ and $b$ are blue. When I hit Shif+Enter, the $x$ turns black, indicating the kernel now knows this variable. But when I input $x_r = a + b$, and hit Shift+Enter, ... - asked by user303446 (1 vote)
================================== Top new questions this week: ================================== [Format and TeXForm does not work as expected]\url{http://mathematica.stackexchange.com/questions/47417/format-a nd-texform-does-not-work-as-expected} Recently, we had a nice question which brought up an issue that I believe is a bug. In the tutorial Defining Output Formats is an example at the end which doesn't make sense This specifies the ... - asked by halirutan (12 votes), answered by halirutan (4 votes) ---------------------------- [How to implement the Observer design pattern?]\url{http://mathematica.stackexchange.com/questions/47659/how-to-i mplement-the-observer-design-pattern} As a programmer with a history with procedural languages, the Observer design pattern inmediately springs to my mind when attacking certain class of problems, mostly UI/notifications related. A ... - asked by Fallible (11 votes), answered by Leonid Shifrin (9 votes) ---------------------------- [How should I reproduce this colorful swirling gif?]\url{http://mathematica.stackexchange.com/questions/47597/how-should-i -reproduce-this-colorful-swirling-gif} Surfing on the web, I came upon this cool gif: Does any one know how to reproduce this in Mathematica? I have some ideas myself, so I will try to answer this question as well. - asked by Ali (10 votes), answered by Kuba (20 votes) ---------------------------- [How to create Line Chart with real third coordinates?]\url{http://mathematica.stackexchange.com/questions/47541/how- to-create-line-chart-with-real-third-coordinates} I would like to generate something like 3D Line Chart in Excel. Like the following figure but including third coordinates. Example I have a set of 2D data combied with 1D spatial data. dxy = ... - asked by Vica (9 votes), answered by Yves Klett (2 votes) ---------------------------- [How can I tell how much memory is taken by an expression?]\url{http://mathematica.stackexchange.com/questions/47491/how-c an-i-tell-how-much-memory-is-taken-by-an-expression} ByteCount and LeafCount don't really work, as shown below. Mathematica 9.0 .. on a 32 bit Windows machine. f[n_] := Block[{k = f[n - 1]}, {k, k}] f[0] = x LeafCount[f[k]] for particular small ... - asked by Richard Fateman (7 votes), answered by billisphere (5 votes) ---------------------------- [Simplify with Assumptions Sqrt[(expr)^2]]\url{http://mathematica.stackexchange.com/questions/47548/si mplify-with-assumptions-sqrtexpr2} While trying to simplify expressions in the form Sqrt[(expr)^2] when expr>0 I noticed a peculiar behavior that was not resolved with code from this Q&A. Simplify[Sqrt[(x - y + a b c)^2], x - y ... - asked by tchronis (6 votes), answered by Simon Woods (9 votes) ---------------------------- [How to use PlotRange -> All with ListLogLinearPlot?]\url{http://mathematica.stackexchange.com/questions/4739 3/how-to-use-plotrange-all-with-listloglinearplot} I would like to generate a ListLogLinearPlot that automatically shows all the data points. However the option PlotRange -> All does not achieve this. Why does All not include all of the data in ... - asked by Italianice (6 votes), answered by Alexey Popkov (3 votes) ================================== Greatest hits from previous weeks: ================================== [How to determine the center and radius of a circle given three points in 3D?]\url{http://mathematica.stackexchange.com/questions/16209/how-to-determ ine-the-center-and-radius-of-a-circle-given-three-points-in-3d} I was wondering if anyone could give me a hand with this problem I have. I have six points on a plane, and I am trying to determine if they form a circle or not. I know that any three points in 2D ... - asked by RedPotatoe (9 votes), answered by Mark McClure (15 votes) ---------------------------- [What is the best Mathematica tutorial for young people?]\url{http://mathematica.stackexchange.com/questions/733/what-is-the -best-mathematica-tutorial-for-young-people} As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ... - asked by noisy (32 votes), answered by Vitaliy Kaurov (17 votes) ================================== Can you answer these? ================================== [Module in numerical model for NonlinearModelFit is slow and leaks memory]\url{http://mathematica.stackexchange.com/questions/47562/module-in- numerical-model-for-nonlinearmodelfit-is-slow-and-leaks-memory} I am trying to make a NonlinearModelFit where the model is the result of a numerical calculation. My code works, but it is very slow and also seems to have a memory leak. I'd appreciate advice about ... - asked by jkrich (3 votes) ---------------------------- [Quantities formatting problem]\url{http://mathematica.stackexchange.com/questions/47515/quantitie s-formatting-problem} So I've developed this simple code Mes /: MakeBoxes[Mes[mess_, error_, unit_], form : (StandardForm | TraditionalForm) : StandardForm ] := RowBox[{ ... - asked by Ranza (2 votes) ---------------------------- [calling CUDA library functions]\url{http://mathematica.stackexchange.com/questions/47702/calling -cuda-library-functions} Mathematica has some predefined CUDA functions, like CUDAMap, CUDAFourier, etc. My question is how can one call functions which are part of CUDA library but not part of predefined Mathematica ... - asked by user1188038 (1 vote)
================================== Top new questions this week: ================================== [May the Fourth be with you]\url{http://mathematica.stackexchange.com/questions/47268/may-the-fourt h-be-with-you} Happy Star Wars day. I was playing around with the image manipulation functions in Mathematica in an attempt to recreate the Star Wars crawl. There's an HTML/CSS implementation which is in my ... - asked by bobthechemist (18 votes), answered by Kuba (19 votes) ---------------------------- [Mathematica 9 cannot solve a difference equation that Mathematica 8 can]\url{http://mathematica.stackexchange.com/questions/47097/mathematica-9 -cannot-solve-a-difference-equation-that-mathematica-8-can} Consider RSolve[{a[n + 1] == 2 a[n] + n (1 + 2^n), a[1] == 1}, a[n], n] Mathematica 8 can solve this quickly, but Mathematica 9, even after being allowed to run for a long time, cannot giva a ... - asked by mathe (14 votes), answered by m_goldberg (3 votes) ---------------------------- [Taking Top K Occurrences]\url{http://mathematica.stackexchange.com/questions/47120/takin g-top-k-occurrences} Having millions of numbers in a list, I want to take top K occurrences. MMA Commonest is very slow so I write my own versions: a=RandomInteger[{1,1000000},50000000]; ... - asked by Mohsen Afshin (12 votes), answered by Mr.Wizard (11 votes) ---------------------------- [Parametric Interpolation of 2D data]\url{http://mathematica.stackexchange.com/questions/47332/parametric-i nterpolation-of-2d-data} I want to create an interpolation through the following 2dim data points: data = {{22.78, 0.2431}, {22.06, 0.262}, {21.51, 0.2774}, {21.07, 0.2905}, {20.7, 0.302}, {20.38, 0.3121}, {20.1, ... - asked by Martin (11 votes), answered by bobthechemist (11 votes) ---------------------------- [Importing an mx file into a context]\url{http://mathematica.stackexchange.com/questions/47110/importing -an-mx-file-into-a-context} Consider the following simple code which dumps the global context: var = 5; DumpSave["test.mx", "Global`"]; Now, in a new notebook, I would like to import var in another context. Trying ... - asked by Massimo Ortolano (10 votes), answered by Leonid Shifrin (11 votes) ---------------------------- [Faster "stuttering" accumulate?]\url{http://mathematica.stackexchange.com/questions/47296/faste r-stuttering-accumulate} Given some list of arbitrary precision numbers, e.g. (actual lists are 1M+ elements long): test={0, 2, 2, 47839283, 2, 0, 0, 2, 0, 1, 2, 0} I need to accumulate the list, but where a specified ... - asked by rasher (9 votes), answered by Mr.Wizard (10 votes) ---------------------------- [Why is this semicolon in red?]\url{http://mathematica.stackexchange.com/questions/47113/why-is-this- semicolon-in-red} I have a piece of code that works well, but when I put a semicolon after a plotting statement, the semicolon appears in red. What's the error? - asked by Mika Ike (9 votes), answered by Kuba (12 votes) ================================== Greatest hits from previous weeks: ================================== [Generate a Unit Circle Trigonometry]\url{http://mathematica.stackexchange.com/questions/2456/gener ate-a-unit-circle-trigonometry} Struggling often with Trigonometry I would like to have some code to generate this Unit Circle Trigonometry. Would be of great help when I need to transform some data : - asked by 500 (13 votes), answered by Mark McClure (27 votes) ---------------------------- [Can Mathematica do symbolic linear algebra?]\url{http://mathematica.stackexchange.com/questions/3242/can-mathe matica-do-symbolic-linear-algebra} For instance, is there some way I can say "let A and B be arbitrary real $m\times n$ and $k\times m$ matrices, Simplify[Transpose[Transpose[A].Transpose[B]]]" and Mathematica would simplify it to B.A? ... - asked by nikie (22 votes), answered by helen (11 votes) ================================== Can you answer these? ================================== [Travel time sweet spot using: Mathematica and Google Maps API]\url{http://mathematica.stackexchange.com/questions/47198/travel-time-s weet-spot-using-mathematica-and-google-maps-api} I want to use Mathematica to do some time minimisation calculations calling on Google Maps API for travel time data. I'm concerned with travel time, e.g. along roads (by car or walk) and not linear ... - asked by PeteCog (1 vote) ---------------------------- [Graphics always rendered twice with SimpleFrontEnd example?]\url{http://mathematica.stackexchange.com/questions/47304/graphics -always-rendered-twice-with-simplefrontend-example} I am looking at the Java SimpleFrontEnd example provided by Mathematica. Everything goes well except it always renders graphics twice. Can anyone help me with this? BTW: I am using version 9 under ... - asked by Michael (2 votes) ---------------------------- [How to specify initial condition including integral equations in the case of the dirac equations?]\url{http://mathematica.stackexchange.com/questions/47358/how-to -specify-initial-condition-including-integral-equations-in-the-case-of-t he} Hi I am trying to solve a system of differential equation with NDSolve. The problem is I have like $3$ (maybe $5$) boundary conditions, but only $2$ differential equations. The equations to solve are ... - asked by Terratoss (1 vote)
================================== Top new questions this week: ================================== [Programming paradigm change]\url{http://mathematica.stackexchange.com/questions/45829/programmin g-paradigm-change} I'm new to Mathematica, I've been learning by myself, and, being a Java developer for some time, it makes it hard to adapt. I've tried to solve a Reddit challenge, and I came up with this solution: ... - asked by MHero (20 votes), answered by WReach (30 votes) ---------------------------- [C Code generated from Mathematica not working?]\url{http://mathematica.stackexchange.com/questions/45619/c-code-g enerated-from-mathematica-not-working} I am a .Net developer. I'm trying to build a Visual C++ application using C code generated from Mathematica (by another person). I don't have Mathematica installed on my machine. When I try to compile ... - asked by pag (10 votes) ---------------------------- [What kind of check does DirectoryQ exactly perform?]\url{http://mathematica.stackexchange.com/questions/45793/what-kin d-of-check-does-directoryq-exactly-perform} I'm using Mathematica 9.0.1 on Windows XP and my drive letters are assigned as follows: C: and D: are hard local disks, while E: is assigned to some removable media. Now, the situation is as follows ... - asked by mitochondrial (9 votes), answered by librik (12 votes) ---------------------------- [What is the most efficient way to map a linked list?]\url{http://mathematica.stackexchange.com/questions/45593/what-is-the -most-efficient-way-to-map-a-linked-list} In order to work with lists effectively using common recursive patterns from functional programming, it's often most convenient to worked with the "linked list" representation, that looks like this: ... - asked by Pillsy (8 votes), answered by Leonid Shifrin (9 votes) ---------------------------- [How to protect functions in a Mathematica Package?]\url{http://mathematica.stackexchange.com/questions/45773/how-to-p rotect-functions-in-a-mathematica-package} I'm writing a Mathematica Package with many functions, but only two can be seen/public. I have: BeginPackage["VolumeReserves`"]; startInterface::usage = "..."; detailRock::usage = "..."; (* ... - asked by Lory Lory (8 votes), answered by halirutan (8 votes) ---------------------------- [How to change the appearance of a group opener?]\url{http://mathematica.stackexchange.com/questions/46082/how-to-ch ange-the-appearance-of-a-group-opener} I would like to change the GroupOpener appearance. In the present Mma design it is too small and can be missed by a reader unfamiliar with Mma. I know, how to change its color through the ... - asked by Alexei Boulbitch (7 votes) ---------------------------- [Equivalence under common permutations]\url{http://mathematica.stackexchange.com/questions/45851/equi valence-under-common-permutations} I have lists which consists of sublists of equal length. The outer list is regarded as a multiset (that is, permutations of the sublists don't matter, but repetitions do), but the order in the ... - asked by celtschk (7 votes), answered by Leonid Shifrin (3 votes) ================================== Greatest hits from previous weeks: ================================== [Even Fibonacci numbers]\url{http://mathematica.stackexchange.com/questions/37266/even-fibo nacci-numbers} Today, I found the Euler Project. Problem #2 is Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, ... - asked by Tangshutao (22 votes), answered by rcollyer (29 votes) ---------------------------- [Problem with NonlinearModelFit]\url{http://mathematica.stackexchange.com/questions/2309/ problem-with-nonlinearmodelfit} I'm having trouble with a non-linear fit: fit = NonlinearModelFit[data, y0 + A Sin[\[Pi] (x - xc)/w], {y0, xc, A, w}, x] where data has about 15 thousand points and looks like this: The data ... - asked by becko (14 votes), answered by Oleksandr R. (25 votes) ================================== Can you answer these? ================================== [Automatic replacing of [ with []]\url{http://mathematica.stackexchange.com/questions/45992/automatic-repl acing-of-with} I tried to modify the KeyEventTranslations.tr file in order to always place a closed bracket instead of an open bracket once I press [. However once I press [ after the modification nothing happens ... - asked by Max1 (6 votes) ---------------------------- [Setting an initial value for ListAnimate?]\url{http://mathematica.stackexchange.com/questions/45892/sett ing-an-initial-value-for-listanimate} ListAnimate is fairly similar to Manipulate, but while Manipulate has a simple way to request an initial value for the manipulation parameter, I haven't found a way to tell ListAnimate to start with a ... - asked by Steve (1 vote) ---------------------------- [How can I select two lists from a list of lists so that I receive the system of equations has only rational solutions?]\url{http://mathematica.stackexchange.com/questions/45877/how-ca n-i-select-two-lists-from-a-list-of-lists-so-that-i-receive-the-system-o f} I want to make a sytem of equations has the form $$\begin{cases} a_1x^2+b_1y^2 + c_1xy+d_1x + e_1y+3=0,\\ a_2x^2+b_2y^2 + c_2xy+d_2x + e_2y+3=0. \end{cases}$$ so that the given system of equations has ... - asked by minthao_2011 (1 vote)
================================== Top new questions this week: ================================== [Creating sculptural forms using graphics primitives]\url{http://mathematica.stackexchange.com/questions/44858/creati ng-sculptural-forms-using-graphics-primitives} This is a question based on this answer by halirutan. Some amazing images can be created with this code, and I was wondering whether it was possible to extend the principle to different shapes. I ... - asked by martin (16 votes), answered by Szabolcs (15 votes) ---------------------------- [Making Monte Carlo simulation with ParallelTable]\url{http://mathematica.stackexchange.com/questions/44917/mak ing-monte-carlo-simulation-with-paralleltable} I would like to to MonteCarlo simulations of various regressions - basically, doing OLS under various conditions to test approaches. On my macpro 2x 2.8 GHz quad core Xeon, 32 Gb RAM DDR2 @ 667 Mhz, ... - asked by guylhem (14 votes), answered by Szabolcs (7 votes) ---------------------------- [Bug with SparseArray selector in Pick]\url{http://mathematica.stackexchange.com/questions/44868/bug-with-spa rsearray-selector-in-pick} I have created a notebook with two cells. This is the content of the first: g = Graph[{1 \[UndirectedEdge] 2, 2 \[UndirectedEdge] 3, 1 \[UndirectedEdge] 3, 1 \[UndirectedEdge] 4, 4 \[UndirectedEdge] ... - asked by Adam Reith (11 votes), answered by Istvan Zachar (8 votes) ---------------------------- [Image Processing: Edge detection of the tumor on tomogram. Calculation area of the tumor] \url{http://mathematica.stackexchange.com/questions/44809/image-processing-edge-detection-of-the-tumor-on-tomogram-alculation-area-of-t} The task is to identify the image region of the tumor. I try to use example from documentation centre: tom1 = Import["http://i.stack.imgur.com/mZ4fR.jpg"]; tumor = SelectComponents[ ... - asked by Alex Skudarev (10 votes), answered by halirutan (12 votes) ---------------------------- [Applying non-Affine transforms to 2D polygons with textures]\url{http://mathematica.stackexchange.com/questions/44863/applying -non-affine-transforms-to-2d-polygons-with-textures} I am trying to create a vanishing point perspective transformation of 2D polygons, for example transforming the red polygon into the blue polygon: p1 = Polygon[{{0, 0}, {1, 0}, {1, 1}, {0, 1}}]; p2 = ... - asked by bobthechemist (8 votes), answered by Silvia (6 votes) ---------------------------- [How does Mathematica understand branchcuts of the complex logarithm?]\url{http://mathematica.stackexchange.com/questions/44767/how-do es-mathematica-understand-branchcuts-of-the-complex-logarithm} Say I have the function $f(x) = x \tanh(\pi x) \log (x^2 +a^2)$ where $a$ is some positive real number. Then it seems to be me that Mathematica when given such a Log[] function implicitly puts a ... - asked by user6818 (7 votes), answered by Jens (14 votes) ---------------------------- [Morphological Components with periodic boundary conditions]\url{http://mathematica.stackexchange.com/questions/44924/morpho logical-components-with-periodic-boundary-conditions} I would like to find the connected(with periodic boundary conditions) components in a large binary matrix. What I've tried, and it does a fair job is: MorphologicalComponents[RandomInteger[{0, 1}, ... - asked by Ali (7 votes), answered by David Carraher (10 votes) ================================== Greatest hits from previous weeks: ================================== [Resources for beautiful Mathematica Stylesheets]\url{http://mathematica.stackexchange.com/questions/5846/resour ces-for-beautiful-mathematica-stylesheets} When the Wolfram Demonstrations were introduced and the Documentation-Center was redesigned, I remember it was the first time I thought someone had put some effort into creating a beautiful ... - asked by halirutan (76 votes), answered by rm -rf (38 votes) ---------------------------- [What is the best Mathematica tutorial for young people?]\url{http://mathematica.stackexchange.com/questions/733/what-is-the -best-mathematica-tutorial-for-young-people} As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ... - asked by noisy (31 votes), answered by Vitaliy Kaurov (17 votes) ================================== Can you answer these? ================================== [Challenge: Creating Compilable Permutations Function]\url{http://mathematica.stackexchange.com/questions/44949/challeng e-creating-compilable-permutations-function} As Mathematica's implemented Permuations function is not compilable I tried to write my very own Permutations implementation, called PermutationsNew, which I want to compile later on. Unfortunately ... - asked by Wizard (1 vote) ---------------------------- [Notation, Format and Interpretation]\url{http://mathematica.stackexchange.com/questions/44986/no tation-format-and-interpretation} I am unclear on the exact relationship between Notation, Format and Interpretation. Format[X] := Y seems similar to Notation[Y <= X] for formating and Interpretation[X, Y] seems related to ... - asked by Daniel Mahler (2 votes) ---------------------------- [Speed up MinimalPolynomial]\url{http://mathematica.stackexchange.com/questions/44763 /speed-up-minimalpolynomial} My Mathematica code runs slowly MinimalPolynomial[Sqrt[2] + Sqrt[3]+ Sqrt[5]+ Sqrt[7]+ Sqrt[11]+ Sqrt[13], x] runs slowly, but the Maple version ... - asked by user13209 (1 vote)
================================== Top new questions this week: ================================== [How to make a curve selectable from a scaned image and convert it to a list of coordinates]\url{http://mathematica.stackexchange.com/questions/44355/how-t o-make-a-curve-selectable-from-a-scaned-image-and-convert-it-to-a-list-o f-c} I have a scanned image (binary-ized): Is there any way to reduce one of these curved lines (full or dotted) to a series of its coordinates (e.g., sampling interval of 0.01 on x-axis)? I've read ... - asked by Tough Kid (10 votes), answered by Alexei Boulbitch (11 votes) ---------------------------- [Alternating sum]\url{http://mathematica.stackexchange.com/questions/44564/alternating-s um} A frog is at the bottom of a 30 metre well. Each day it climbs 5 metres up the side, but it then slips back 3 metres each night. How long does it take to reach the top of the well? Is there an easier ... - asked by martin (7 votes), answered by Leonid Shifrin (5 votes) ---------------------------- [How to extract the edge from a set of points]\url{http://mathematica.stackexchange.com/questions/44694/how-to-ext ract-the-edge-from-a-set-of-points} I have an accumulation of points representing a body as you can see in the image below. From this data I want to generate a list of points or a curve, which is the envelope. The first idea was a ... - asked by zeckra (6 votes), answered by halirutan (4 votes) ---------------------------- [Map of Specific US States? (Isolated)]\url{http://mathematica.stackexchange.com/questions/44505/map-of -specific-us-states-isolated} My question here is fairly basic, and I'm sure I'm overlooking something basic. I know about CountryData for creating shapes of entire countries, and it works, to an extent; I can plot geographical ... - asked by Smith W. (6 votes), answered by Pickett (5 votes) ---------------------------- [Exporting EPS figures with dashing from ListPlot]\url{http://mathematica.stackexchange.com/questions/44560/exportin g-eps-figures-with-dashing-from-listplot} I am having difficulties exporting EPS figures. If I use the LineLegend option to create a dashed or a dot-dashed line, it seems ok in Mathematica 9.0 e.g.: But the problem came out when the ... - asked by Qu8k (5 votes), answered by george2079 (6 votes) ---------------------------- [How to import a large (~50Mb) json file in mathematica]\url{http://mathematica.stackexchange.com/questions/44671/how-t o-import-a-large-50mb-json-file-in-mathematica} I am trying to import a 46Mb json file into mathematica (which by the way I exported using mathematica) but its failing with the following messages: Java::pexcptn: A Java exception occurred after the ... - asked by Trollkemada (5 votes), answered by Sjoerd C. de Vries (4 votes) ---------------------------- [How to select only NotebookObjects that are referring to ordinary notebooks? (not palettes etc.)]\url{http://mathematica.stackexchange.com/questions/44588/how-to-sele ct-only-notebookobjects-that-are-referring-to-ordinary-notebooks-no} There is of course function Notebooks[] But, unfortunatelly it hasn't got useful options in this context. My question is how to pick Notebooks excluding: Help, Palettes, Packages, ... - asked by Kuba (5 votes), answered by Kuba (3 votes) ================================== Greatest hits from previous weeks: ================================== [What is the best Mathematica tutorial for young people?]\url{http://mathematica.stackexchange.com/questions/733/what-is-the -best-mathematica-tutorial-for-young-people} As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ... - asked by noisy (31 votes), answered by Vitaliy Kaurov (17 votes) ---------------------------- [Problem with NonlinearModelFit]\url{http://mathematica.stackexchange.com/questions/2309/ problem-with-nonlinearmodelfit} I'm having trouble with a non-linear fit: fit = NonlinearModelFit[data, y0 + A Sin[\[Pi] (x - xc)/w], {y0, xc, A, w}, x] where data has about 15 thousand points and looks like this: The data ... - asked by becko (14 votes), answered by Oleksandr R. (23 votes) ================================== Can you answer these? ================================== [Maintaining postfix convention for directives in notebooks]\url{http://mathematica.stackexchange.com/questions/44606/maintai ning-postfix-convention-for-directives-in-notebooks} It seems to be a fairly common convention to write certain 'meta' functions in postfix form like f[x] // Simplify to keep the the mathematical content at the front separate from the various ... - asked by Daniel Mahler (2 votes) ---------------------------- [Function behavior based on Head]\url{http://mathematica.stackexchange.com/questions/44425/function-beh avior-based-on-head} I'm figuring how to implement a function behavior based on the Head of its argument. I mean Unprotect@Head; Head[p_[x]]:= Kind; Protect@Head; function[h_]:= 0; function[p_Kind]:= 1; Head[f[x]] ... - asked by Fabio (1 vote) ---------------------------- [Controlling output of graphics, the role of ";" and code structure/formatting]\url{http://mathematica.stackexchange.com/questions/44 630/controlling-output-of-graphics-the-role-of-and-code-structure-format ting} ";" is described under Compound Expression as a delimiter, such that only the output of the last item in the compund expression is given. Situation: 1/ Print[] produces output whether followed by ... - asked by Julian Moore (1 vote)
================================== Top new questions this week: ================================== [What does ImageSize -> 1 -> 1 mean?]\url{http://mathematica.stackexchange.com/questions/43820/what-does-i magesize-1-1-mean} On the page http://www.wolfram.com/language/gallery/blur-faces-in-an-image/ the example code has ImageSize -> 1 -> 1. I am unfamiliar with this chaining of rules... What does it mean? Note I ... - asked by PeterR (16 votes), answered by rm -rf (13 votes) ---------------------------- [Web Browser Screen Shot]\url{http://mathematica.stackexchange.com/questions/44099/web-browser- screen-shot} I have Safari, Opera, Chrome, Firefox and IE installed how might a get a browser screen shot of a set of HTML code from inside Mathematica(for any of those browsers)? (Image is optional) The ... - asked by Liam William (15 votes), answered by WReach (23 votes) ---------------------------- [What is the fastest way to extract a substring from a huge string?]\url{http://mathematica.stackexchange.com/questions/44175/what-is-t he-fastest-way-to-extract-a-substring-from-a-huge-string} I develop an algorithm to find the most common substrings of a given length n up to a certain distance l in front of a pattern p in a huge sequence S. E.g. I want to find the most common hexamers ... - asked by g3kk0 (8 votes), answered by Leonid Shifrin (9 votes) ---------------------------- [Fast way of finding position of Interval containing an Integer]\url{http://mathematica.stackexchange.com/questions/43885/fast-way- of-finding-position-of-interval-containing-an-integer} I have a large list (about 2.2 million) of pairs of integers. Each pair defines an Interval[{}]. Given some integer x, I need to find the position of the interval in my list that bounds x (or ... - asked by user1375062 (8 votes), answered by Leonid Shifrin (12 votes) ---------------------------- [How to calcuate the sum of 1/x, where x is an integer not containing the digit 9 and 10,000,000 <= x <= 88,888,888] \url{http://mathematica.stackexchange.com/questions/43919/how-to-calcuate-the-sum-of-1-x-where-x-is-an-integer-not-containing-the-digit-9} My code is: nonine[x_] := If[StringMatchQ[IntegerString[x], "*9*"], False, True]; SetAttribute[nonine, Listable]; tbl = Select[Range[10^2, 888], nonine[#] &]; Total[1.0/tbl] got out of memory ... - asked by user2218402 (7 votes), answered by Simon Woods (10 votes) ---------------------------- [Compile function which calls other functions to C]\url{http://mathematica.stackexchange.com/questions/44226/compile-functio n-which-calls-other-functions-to-c} I have a function which calls other functions and I would like to compile it to C code. For example: foo[p_] := 0.7 Exp[-p^2] f[a_, n_] := Module[{s, p, i}, s = 0; p = a; For[i = 0, i < n, ... - asked by Danvil (6 votes), answered by halirutan (7 votes) ---------------------------- [Mathematica-To-MATLAB Dictionary!]\url{http://mathematica.stackexchange.com/questions/44223/mathe matica-to-matlab-dictionary} Is there a dictionary to translate Mathematica functions and commands to MATLAB? - asked by Behzad (6 votes), answered by ndetermin (4 votes) ================================== Greatest hits from previous weeks: ================================== [Problem with NonlinearModelFit]\url{http://mathematica.stackexchange.com/questions/2309/ problem-with-nonlinearmodelfit} I'm having trouble with a non-linear fit: fit = NonlinearModelFit[data, y0 + A Sin[\[Pi] (x - xc)/w], {y0, xc, A, w}, x] where data has about 15 thousand points and looks like this: The data ... - asked by becko (14 votes), answered by Oleksandr R. (23 votes) ---------------------------- [How to find the phase difference of two sampled sine waves?]\url{http://mathematica.stackexchange.com/questions/11046/how-to-fin d-the-phase-difference-of-two-sampled-sine-waves} I'm trying to measure a phase difference between two Sine functions I've acquired with a computer. I'm uploading one of the .txt files with the data I'm working with here: txt file. To remove the ... - asked by Juan (20 votes), answered by bill s (18 votes) ================================== Can you answer these? ================================== [RSolve: Errors while solving Partial Difference Equation]\url{http://mathematica.stackexchange.com/questions/44194/rsolve-e rrors-while-solving-partial-difference-equation} I tried solving following partial difference equation in Mathematica by typing RSolve[{C[n, k] == C[n-1, k] + C[n-1, k-1], C[n, 0] == 1, C[n, n] == 1}, C[n, k], {n, k}] but returns the following ... - asked by user136040 (1 vote) ---------------------------- [How to apply an rule to factors matching a certain form]\url{http://mathematica.stackexchange.com/questions/43903/how-to-apply -an-rule-to-factors-matching-a-certain-form} Suppose we have many expressions involving irrational ArcTan expressions (such as ArcTan[Sqrt[3],5]) along with other irrational factors (such as 1/Sqrt[2]). I want to simplify all of these ... - asked by Steve (1 vote) ---------------------------- [How to make noncommutative multiplication agree with commutative multiplication]\url{http://mathematica.stackexchange.com/questions/44157/ho w-to-make-noncommutative-multiplication-agree-with-commutative-multiplic ation} I need a noncommutative multiplication that is Associative Distributive $A**0=0$, $A**1=A$ Agrees with the commutative multiplication ($A**(k B)=(k A)**B=k (A**B)$) I have found a code ... - asked by 8k14 (1 vote)
================================== Top new questions this week: ================================== [Most influential and/or disrupting features introduced with new versions of Mathematica]\url{http://mathematica.stackexchange.com/questions/43631/most- influential-and-or-disrupting-features-introduced-with-new-versions-of-m ath} This is something that has been bugging me for ages. With every upgrade, Mathematica has added new functionalities and amendend some of its bugs. In the process, though, some older functionality has ... - asked by Peltio (11 votes), answered by Mark Adler (3 votes) ---------------------------- [Fast way to get positions of "boxed" array elements?]\url{http://mathematica.stackexchange.com/questions/43557/fast-wa y-to-get-positions-of-boxed-array-elements} Given a 2D array (arbitrary numeric / evaluates to numeric elements, simplified for examples, and can be arbitrary dimensions so long as the operation makes sense, I'm working with 2K X 2K in my ... - asked by rasher (9 votes), answered by rasher (6 votes) ---------------------------- [Drop selection of columns from a ragged array]\url{http://mathematica.stackexchange.com/questions/43785/drop-select ion-of-columns-from-a-ragged-array} I have an application where I need to drop some arbitrary list of columns from a ragged array (where of course the shortest array rows have at least all the specified columns). E.g., given a ragged ... - asked by rasher (8 votes), answered by Mr.Wizard (6 votes) ---------------------------- [How to match a cyclically repeating sequence?]\url{http://mathematica.stackexchange.com/questions/43801/how-to- match-a-cyclically-repeating-sequence} I have run across several times recently where I must match a sequence that is cyclically repeating. For example, with the sequence, Sequence[a, b, c] how would I write a pattern that matched ... - asked by rcollyer (7 votes), answered by rm -rf (3 votes) ---------------------------- [Is there a function which instantly tells you whether an element is part of a list?]\url{http://mathematica.stackexchange.com/questions/43541/is-there-a- function-which-instantly-tells-you-whether-an-element-is-part-of-a-li} I have a very long list of numbers and I want to check whether there's a function (something that would look like PartOfQ[element,list]) that tells you immediately with a True or False as to whether ... - asked by Aron (7 votes), answered by Szabolcs (7 votes) ---------------------------- [Suppress connection to Wolfram|Alpha when making unit conversions]\url{http://mathematica.stackexchange.com/questions/43515/suppr ess-connection-to-wolframalpha-when-making-unit-conversions} I want to speed up calculations with unit conversions. I suspect primarily that some units evaluate from Wolfram|Alpha. Any way to prevent this automatically, so that Mathematica throws ... - asked by denfromufa (7 votes), answered by rm -rf (5 votes) ---------------------------- [How to handle keyboard events for unselected item in CDF?]\url{http://mathematica.stackexchange.com/questions/43432/how-to-handl e-keyboard-events-for-unselected-item-in-cdf} How can I force the keyboard input to work for this cell without clicking on it after I evaluate or showing a blinking selection cursor? This is for running CDF games in a browser. pos = {0, 0}; ... - asked by Michael Hale (6 votes), answered by Michael Hale (3 votes) ================================== Greatest hits from previous weeks: ================================== [3D heatmap density plot]\url{http://mathematica.stackexchange.com/questions/17260/3d-heatmap-d ensity-plot} I have a set of data that looks like {{x1, y1, z1}, {x2, y2, z2}, ...} so it describes points in 3D space. I want to make a heatmap out of this data. So that points with a high density are shown as a ... - asked by norty (25 votes), answered by PlatoManiac (27 votes) ---------------------------- [Plotting the frequency spectrum of a data series using Fourier]\url{http://mathematica.stackexchange.com/questions/18082/plotting- the-frequency-spectrum-of-a-data-series-using-fourier} testData = Table[N@Sin[500 x], {x, 0, 100}]; ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full] Gives me Which I do not expect because the Fourier Transform is FourierTransform[Sin[500 ... - asked by Pickett (7 votes), answered by KennyColnago (8 votes) ================================== Can you answer these? ================================== [Fourier transformation of HeavisideTheta functions]\url{http://mathematica.stackexchange.com/questions/43445/fourier -transformation-of-heavisidetheta-functions} I want to find 2D-Fourier transformation of the function given below f = HeavisideTheta[y1]*HeavisideTheta[y2 - y1] For the purpose, I use built-in function in two ways as below, ... - asked by user58226 (3 votes) ---------------------------- [Autocomplete from inside Module and SetDelayed]\url{http://mathematica.stackexchange.com/questions/43393/autoco mplete-from-inside-module-and-setdelayed} Autocomplete in Mathematica 9 offers suggestions from inside SetDelayed and Module. For example, after running: func[thing1_, thing2_] := thing1 + thing2; Module[{thing3}, thing3 = 10; thing3 + 4 ] ... - asked by Italianice (1 vote) ---------------------------- [Slow mixture fitting when having ill-conditioned covariance matrices. How to make it faster?]\url{http://mathematica.stackexchange.com/questions/43592/slow-mixt ure-fitting-when-having-ill-conditioned-covariance-matrices-how-to-mak} I'm using Mathematica 9.0 to fit multidimensional observations with a gaussian mixture. To do so I first adapted these steps to ensure that the mixture parameters are well defined (see ... - asked by p-d (1 vote)
================================== Top new questions this week: ================================== [How can I add drop shadows and specular highlights to 2D graphics?]\url{http://mathematica.stackexchange.com/questions/43186/how-can -i-add-drop-shadows-and-specular-highlights-to-2d-graphics} I thought I'd share some code in the form of a self-answered question, but other answers are of course welcome. Drop shadows are a familiar visual effect, giving the impression of a graphical element ... - asked by Simon Woods (26 votes), answered by Simon Woods (29 votes) ---------------------------- [Are greek symbols causing different evaluation?]\url{http://mathematica.stackexchange.com/questions/43108/are-g reek-symbols-causing-different-evaluation} I've updated today to Mathematica 9.0.1.0 from version 8 and found something that absolutely confuses me. Let us define a piecewise function: gr[x_, v1_, v2_, v3_, v4_, v5_] = Piecewise[{{g, v1 ... - asked by Mike (14 votes) ---------------------------- [How to make a function with its own options as well as passing options to other functions]\url{http://mathematica.stackexchange.com/questions/43088/how-to- make-a-function-with-its-own-options-as-well-as-passing-options-to-other > } I have a function with many of its own options, but I would also like to pass options to subfunctions using the FilterRules function. Here's a simple example: Options[pfunc] = {"test" -> True}; ... - asked by Jason B (11 votes), answered by rm -rf (8 votes) ---------------------------- [Why the Block command does not forget the $ContextPath variable]\url{http://mathematica.stackexchange.com/questions/43137/why-the- block-command-does-not-forget-the-contextpath-variable} I do not understand this behavior: method[args_] := (* forget the context path *) Block[{$ContextPath}, (* should given nothing, right? *) Print["cpath=", $ContextPath]; ... - asked by zorank (11 votes), answered by Szabolcs (8 votes) ---------------------------- [Third argument of Compile]\url{http://mathematica.stackexchange.com/questions/43128/third-arg ument-of-compile} In his last comment on this answer, halirutan shows an example in which the third argument of Compile does not have any effect. The example is as follows. cfu = Compile[{}, Module[{y = {}}, ... - asked by Jacob Akkerboom (11 votes), answered by halirutan (5 votes) ---------------------------- [Plot Matlab icon]\url{http://mathematica.stackexchange.com/questions/43012/plot-matlab- icon} I started to explore this on a whim and hasn't succeeded yet Some introduction for the icon is found here but I can't understand it very well. (I admit that, though playing with NDSolve a lot, I ... - asked by xzczd (8 votes), answered by episanty (10 votes) ---------------------------- [Why does Plot[Hold[x], {x,0,1}] work?]\url{http://mathematica.stackexchange.com/questions/43318/why-does-pl otholdx-x-0-1-work} It appears that, counter to my expectation, all of these (and probably many others) seem to work fine: Plot[Hold[x], {x, 0, 10}] FindRoot[Hold[x^2 == 2], {x, 1}] NMinimize[Hold[x^2], x] I would ... - asked by Szabolcs (8 votes), answered by Michael E2 (5 votes) ================================== Greatest hits from previous weeks: ================================== [Plotting the frequency spectrum of a data series using Fourier]\url{http://mathematica.stackexchange.com/questions/18082/plotting- the-frequency-spectrum-of-a-data-series-using-fourier} testData = Table[N@Sin[500 x], {x, 0, 100}]; ListLinePlot[Abs[Fourier[testData]], PlotRange -> Full] Gives me Which I do not expect because the Fourier Transform is FourierTransform[Sin[500 ... - asked by Pickett (7 votes), answered by KennyColnago (8 votes) ---------------------------- [Get a "step by step" evaluation in Mathematica]\url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (45 votes), answered by J.M. (41 votes) ================================== Can you answer these? ================================== [Is there a package or canonical way for writing test harnesses in Mathematica?]\url{http://mathematica.stackexchange.com/questions/43014/is-t here-a-package-or-canonical-way-for-writing-test-harnesses-in-mathematic a} I've written a complicated function foo.1 I'd now like to simplify this function's code, and later enhance it with more features. With each change, however, I'd like to be confident that I'm not ... - asked by acheong87 (2 votes) ---------------------------- [Young Tableaux Miscellanea]\url{http://mathematica.stackexchange.com/questions/43157/young -tableaux-miscellanea} I have a problem which is mostly neatly described by using Young Tableaux. Mathematica seems to have these Tableaux built in, except that the Tableaux function is only in Combinatorica. When I ... - asked by evanb (2 votes) ---------------------------- [Assign a value to a variable without using Set or SetDelayed?]\url{http://mathematica.stackexchange.com/questions/43306/assig n-a-value-to-a-variable-without-using-set-or-setdelayed} I supose probably yes, but at the end I assume that internally mathematica has to use Set or SetDelayed. Am I right? Background: I am developing a super simple phraser that takes a code description ... - asked by zorank (1 vote)
================================== Top new questions this week: ================================== [Implementing a Beeswarm plot in Mathematica]\url{http://mathematica.stackexchange.com/questions/42585/imple menting-a-beeswarm-plot-in-mathematica} I am looking for a Beeswarm plot implementation in Mathematica. Consider the following data: data = {RandomVariate[NormalDistribution[], 100], RandomVariate[NormalDistribution[], 100]}; Lets ... - asked by Pam (16 votes), answered by Szabolcs (10 votes) ---------------------------- [Object differentiation in image]\url{http://mathematica.stackexchange.com/questions/42809/object-diff erentiation-in-image} After purchasing a box of alphabet pasta for the kids, I wondered if there was way to extract the frequency of appearance of letters in the box by taken a sample and the analyzing the picture. i = ... - asked by PatoCriollo (10 votes), answered by lalmei (2 votes) ---------------------------- [Why does $Failed have attribute HoldAll?]\url{http://mathematica.stackexchange.com/questions/42531/why-does -failed-have-attribute-holdall} Why does $Failed have attribute HoldAll? Are there typical situations where $Failed is returned as a head that must not evaluate further, or is this just a relic from Mathematica's early times? ... - asked by Szabolcs (9 votes), answered by Leonid Shifrin (6 votes) ---------------------------- [When running Mathematica from a Linux terminal, how can I prevent a script from terminating upon logout?]\url{http://mathematica.stackexchange.com/questions/42838/when-runn ing-mathematica-from-a-linux-terminal-how-can-i-prevent-a-script-from} I am running Mathematica on a remote Linux cluster, by the terminal, using the math command. (I do not have access to a terminal GUI. For example, when I type the command mathematica, I get this ... - asked by Andrew (8 votes), answered by Stefan (12 votes) ---------------------------- [Deleting quasi-duplicates from large list efficiently]\url{http://mathematica.stackexchange.com/questions/42599/delet ing-quasi-duplicates-from-large-list-efficiently} I have the need to remove "duplicates" from large (>10K members) lists, where a "duplicate" is either a verbatim duplication, or the element's second entry exists as a first entry for some "earlier" ... - asked by rasher (8 votes), answered by Mr.Wizard (9 votes) ---------------------------- [Export an image at 1000 dpi]\url{http://mathematica.stackexchange.com/questions/42519/export-an-ima ge-at-1000-dpi} I'm trying to export an image at 1000 dpi. The author guide of a lot of papers wants this resolution! Then I must to import this image in Word in a small box; let's say 7x4 cm. This is the code that I ... - asked by Mary (8 votes), answered by Szabolcs (10 votes) ---------------------------- [Generating Gelfand-Tsetlin patterns]\url{http://mathematica.stackexchange.com/questions/42745/generati ng-gelfand-tsetlin-patterns} I am doing some research on some combinatorial object called GT-patterns. They are generated from three parts of data. Two integer, partitions (sequences of weakly decreasing numbers), $\lambda = ... - asked by Paxinum (7 votes) ================================== Greatest hits from previous weeks: ================================== [How can I improve Mathematica's resolution on a macbook retina display?]\url{http://mathematica.stackexchange.com/questions/18419/how-can- i-improve-mathematicas-resolution-on-a-macbook-retina-display} Mathematica looks a bit fuzzy on the retina screen, how can I increase the resolution? Here another screenshot showing a direct comparison between the browser and Mathematica - asked by Tom Wellington (34 votes), answered by programming_historian (14 votes) ---------------------------- [How to draw a spring?]\url{http://mathematica.stackexchange.com/questions/37207/how-to-dr aw-a-spring} I am new to Mathematica and have recently been exploring graphical animations. So I was experimenting with simple concepts in periodic motion and hence wondered how can I draw a simple spring? Is ... - asked by David McHarg (21 votes), answered by belisarius (26 votes) ================================== Can you answer these? ================================== [Transform an expression to remove the singularity]\url{http://mathematica.stackexchange.com/questions/42634/trans form-an-expression-to-remove-the-singularity} I have the expression Sin[c x]/c. Clearly it is undefined at $c=0$, but that is merely a removable singularity, since $$\frac{\sin(cx)}c=x\frac{\sin(cx)}{cx}= x\operatorname{sinc}(cx),$$ which is ... - asked by Rahul Narain (4 votes) ---------------------------- [Highlighting Mathematica code in LaTeX document]\url{http://mathematica.stackexchange.com/questions/42793/highligh ting-mathematica-code-in-latex-document} I was thinking about the best way to include Mathematica code in a LaTeX document with a nice syntax highlighting. I have tried the packages listings and minted (with pygments), which both claim to ... - asked by Eckhard (5 votes) ---------------------------- [Is there a way to tell mathematica to minimize the number of multiplication in an expression? (Simplify and FullSimplify don't cut it)]\url{http://mathematica.stackexchange.com/questions/42611/is-there-a-wa y-to-tell-mathematica-to-minimize-the-number-of-multiplication-in-a} I have an expression, here's a clip of it: ...LF (LG LQ Lsig^2 + 2 LQ Lsig RG Rl + LG LQ Rl^2 + Lsig^2 RG RQ + 2 LG Lsig Rl RQ + 2 LQ Lsig RG Rs + 2 LG LQ Rl Rs + 2 LG Lsig RQ Rs + LG ... - asked by bwna (2 votes)
================================== Top new questions this week: ================================== [Highlight Pie in PieChart]\url{http://mathematica.stackexchange.com/questions/42201/highligh t-pie-in-piechart} PieChart has the nice functionality of highlighting a single pie when you click on it. It is then sticking out a little. See the following example: PieChart[{1, 2, 3}] Now, if I click on the ... - asked by Markus Roellig (20 votes), answered by Simon Woods (20 votes) ---------------------------- [M9 performance regression for Fold?]\url{http://mathematica.stackexchange.com/questions/42419/m9-performa nce-regression-for-fold} I noticed an over 10x performance drop on Mathematica v9.0.1 (as Oleksandr R. commented, also v8) compared with v7.01 for this code: SetSystemOptions["CatchMachineUnderflow" -> False]; ... - asked by Yi Wang (16 votes) ---------------------------- [Finding the intersection of a curve with an interpolation function]\url{http://mathematica.stackexchange.com/questions/42304/finding- the-intersection-of-a-curve-with-an-interpolation-function} There are no issues trying to find the intersection points of two defined curves. f[x_] := 2 (x - 1) (x - 1.5) (x - .5) (x + .5) (x + 1) (x + 1.5); g[x_] := 0.4 x - 0.4; Solve[f[x] == ... - asked by PatoCriollo (13 votes), answered by Daniel Lichtblau (12 votes) ---------------------------- [How to find out what files are touched when Get is called?]\url{http://mathematica.stackexchange.com/questions/42453/how-to-fi nd-out-what-files-are-touched-when-get-is-called} Is there a way to capture all package files touched whenever a package is called via Get, Needs, Beginpackage or similar? While FindFile["package`"] can point to the first file that is called, the ... - asked by Istvan Zachar (11 votes), answered by Istvan Zachar (11 votes) ---------------------------- [Rearranging a List]\url{http://mathematica.stackexchange.com/questions/42219/rearranging- a-list} I am trying to rearrange/sort a list i.e. {{1,2},{10,140},{43,10},{1,140},{43,2}} into {{1,2},{2,43},{43,10},{10,140},{140,1}} or any cyclic permutation of it. The numbers don't repeat more ... - asked by lalmei (9 votes), answered by Leonid Shifrin (6 votes) ---------------------------- [What are the differences between library call back functions and WolframCompileLibrary macros?]\url{http://mathematica.stackexchange.com/questions/42409/what-are- the-differences-between-library-call-back-functions-and-wolframcompilel> ) I'm trying to use LibraryLink in Mathematica, and come across some problems. Consider if we have a MTensor m1 which contains a one dimensional double array, and I want to get the data of that array. ... - asked by xslittlegrass (8 votes), answered by halirutan (6 votes) ---------------------------- [How does PlotLegends actually work with ListPlot3D?]\url{http://mathematica.stackexchange.com/questions/42262/how-d oes-plotlegends-actually-work-with-listplot3d} I'm sensing this might be a rookie mistake but normally I roll my own legends but decided to try the built in legends for a ListPlot3D. PlotLegends is listed as an option for ListPlot3D but curiously ... - asked by Mike Honeychurch (8 votes), answered by rm -rf (10 votes) ================================== Greatest hits from previous weeks: ================================== [Finding all simple paths between two vertices in a graph]\url{http://mathematica.stackexchange.com/questions/25779/finding-all -simple-paths-between-two-vertices-in-a-graph} There are built-in methods to find a shortest path between two vertices in a graph, and the question on finding all shortest paths between two vertices has gathered quite a bit of attention. A path ... - asked by mrm (9 votes), answered by trybik (8 votes) ---------------------------- [What Mathematica book to buy?]\url{http://mathematica.stackexchange.com/questions/5059/what-mathemat ica-book-to-buy} I have used Mathematica for several years but at a pretty low level - piecing together built-in function inefficiently and fearing the sight of # and &'s when I see others use them (I never do). I ... - asked by BeauGeste (26 votes), answered by David (39 votes) ================================== Can you answer these? ================================== [How to extract a variable names (not values) from a list of transformation rules?]\url{http://mathematica.stackexchange.com/questions/42405/how-to-ext ract-a-variable-names-not-values-from-a-list-of-transformation-rules} I am trying to extract variable names from a list of transformation rules mapping = {var1 -> 'val1', var2 -> 'val2' }. Variables var1 and var2 are already defined in my notebook: var1 = ... - asked by verse (1 vote) ---------------------------- [Establish connection with RLink and Rtools]\url{http://mathematica.stackexchange.com/questions/42408/establish- connection-with-rlink-and-rtools} Has anyone gotten RLink to work with Rtools (or even tried)? If so a simple step-by-step would be much appreciated ! When attempting to access any Rtools functionality through RLink I get: The ... - asked by David Ross (2 votes) ---------------------------- [NMinimize seems to call function with the same values multiple times]\url{http://mathematica.stackexchange.com/questions/42215/nminimize-s eems-to-call-function-with-the-same-values-multiple-times} I have to minimize a function where the evaluation of one parameter set takes very long (around 5sec) and discovered alongside, that NMinimize seems to call this function multiple times with the exact ... - asked by Frederik Ziebell (3 votes)
================================== Top new questions this week: ================================== [A set of elements]\url{http://mathematica.stackexchange.com/questions/41753/a-set-of -elements} I have a set of say 100 numbers {1,3,7,11,19,...3971}. All elements are previously determined. I want to check whether 376 belongs to this set or not. what is the fastest way? Thanks - asked by Meqdad (9 votes), answered by Mr.Wizard (10 votes) ---------------------------- [Unwanted PlotMarkers appear at non-existent places]\url{http://mathematica.stackexchange.com/questions/41706/unwanted-p lotmarkers-appear-at-non-existent-places} In this simple code ListPlot[Table[Sin[x], {x, 0, Pi, .1}], PlotRange -> {0, 0.5}, Joined -> True, PlotMarkers -> Automatic, ClippingStyle -> None, Frame -> True] We can see that ... - asked by saturasl (9 votes), answered by Coolwater (9 votes) ---------------------------- [Find positions of items in a list based on neighbours]\url{http://mathematica.stackexchange.com/questions/41937/find-p ositions-of-items-in-a-list-based-on-neighbours} How can I select items from a list where the selection criterion depends on the neighbouring items? For example select all indices where a change has occurred with respect to the previous element in ... - asked by Danvil (8 votes), answered by Simon Woods (14 votes) ---------------------------- [How to run mathematica scripts without initializing the kernel every time]\url{http://mathematica.stackexchange.com/questions/41742/how-to-run-m athematica-scripts-without-initializing-the-kernel-every-time} I have written a Mathematica script that is to be run periodically on a Raspberry Pi. The code takes about 3 seconds to execute if I test it in a CLI Mathematica session. However, when I execute the ... - asked by shrx (7 votes), answered by shrx (1 vote) ---------------------------- [Get Coordinates 4 significant digits limitation]\url{http://mathematica.stackexchange.com/questions/42112/get-co ordinates-4-significant-digits-limitation} The tool "get coordinates" (clicking on a plot), seems to work with a fixed number of significant digits (4), in a way that we can quickly lose sensibility (the tool really becomes useless). The ... - asked by P. Fonseca (6 votes), answered by chuy (2 votes) ---------------------------- [How to take derivative of parameterized coordinate?]\url{http://mathematica.stackexchange.com/questions/41907/how-t o-take-derivative-of-parameterized-coordinate} Suppose I have a vector in $\mathbb{R}^n$ but $n$ is not known in advance. I want to be able to write functions which operate on the components of that vector, and then I'd like to be able to take ... - asked by Tom (6 votes) ---------------------------- [How to randomly erode a 3D distribution of points with Mma 7.0?]\url{http://mathematica.stackexchange.com/questions/41801/how-to-rando mly-erode-a-3d-distribution-of-points-with-mma-7-0} Suppose we have a 3D distribution of points, like the spherical ball example below : Ball[num_]:=Table[ { #1 Sqrt[1-#2^2]Cos[#3], #1 Sqrt[1-#2^2]Sin[#3], #1 #2 } &[ ... - asked by Cham (6 votes), answered by chuy (6 votes) ================================== Greatest hits from previous weeks: ================================== [Marking points of intersection between two curves]\url{http://mathematica.stackexchange.com/questions/10472/marking-po ints-of-intersection-between-two-curves} I'm trying to illustrate the solutions numerically and graphically for an equation such as Tan[x] == x. I think I did everything ok except I wanted to mark each intersection between Tan[x] and x. ... - asked by fiz (20 votes), answered by belisarius (30 votes) ---------------------------- [What are the most common pitfalls awaiting new users?]\url{http://mathematica.stackexchange.com/questions/18393/what-are-t he-most-common-pitfalls-awaiting-new-users} As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ... - asked by belisarius (121 votes), answered by Michael E2 (64 votes) ================================== Can you answer these? ================================== [OpenCLLink specify grid size when calling function]\url{http://mathematica.stackexchange.com/questions/41992/openclli nk-specify-grid-size-when-calling-function} The Mathematica documentation (section "Details": https://reference.wolfram.com/mathematica/OpenCLLink/ref/OpenCLFunction. html) states that: On launch, if the number of threads is not specified ... - asked by user2224780 (1 vote) ---------------------------- [Import merged cells from Excel]\url{http://mathematica.stackexchange.com/questions/42069/import-merg ed-cells-from-excel} in a scientific paper I've found some data. I've saved it in Excel from a .pdf file. But it was saved in a strange way: all data are in two cells in Excel. In large merged cells. Now when I try to ... - asked by Mary (1 vote) ---------------------------- [Mysterious behavior of Precision for complex arrays]\url{http://mathematica.stackexchange.com/questions/42075/mysterious -behavior-of-precision-for-complex-arrays} Mysterious behavior of Precision: {{1.0+I*0.0},{0.0+I*0.0}} // SetPrecision[#,30]& // Precision // Print; 0. {{1.0},{0.0}} // SetPrecision[#,30]& // Precision // Print; 30. Why is ... - asked by John Sidles (3 votes)
================================== Top new questions this week: ================================== [Extracting angles from a simple picture]\url{http://mathematica.stackexchange.com/questions/41563/extractin g-angles-from-a-simple-picture} I'm not sure if this is even possible with Mathematica, but I want to extract the angles between all lines in this picture: It consists of $12$ lines, so I want a matrix with $144$ entries. I ... - asked by holistic (13 votes), answered by Kuba (14 votes) ---------------------------- [Shuffle product of two lists]\url{http://mathematica.stackexchange.com/questions/41614/shuffle-pro duct-of-two-lists} I want to do the following: I have two lists {a_1,...a_n}, {b_1,...,b_n} and I would like to build now all shuffles out of this. This means all unions of these lists while still keeping the individual ... - asked by A friendly helper (12 votes), answered by Mr.Wizard (9 votes) ---------------------------- [Strange behavior when using Row with packed arrays]\url{http://mathematica.stackexchange.com/questions/41653/strange-be havior-when-using-row-with-packed-arrays} Today I lost a lot of time with a strange behavior and I narrowed it down to this small piece of code: a = {1, 2}; ToString@Row[DeleteDuplicates[a], ","] ToString@Row[Union[a], ","] "Row[{1, 2}, ... - asked by Murta (11 votes), answered by Szabolcs (11 votes) ---------------------------- [Graphics`Mesh`FindIntersections[ ] fails to detect intersections]\url{http://mathematica.stackexchange.com/questions/41496/gra phicsmeshfindintersections-fails-to-detect-intersections} Graphics`Mesh`FindIntersections[ ] is an undocumented function for, well, detecting intersections very efficiently. Take a look: i = Import@"http://i.stack.imgur.com/PcWcz.png"; perim = ... - asked by belisarius (10 votes) ---------------------------- [Checking through an expression]\url{http://mathematica.stackexchange.com/questions/41324/checki ng-through-an-expression} I am writing a code that manipulates expressions that contains functions with an arbitrary number of arguments. An example expression is expr = x f[a, b, c, d] - 4 f[b, a, d] + z f[] + f[a, b, d] - ... - asked by QuantumDot (7 votes), answered by Artes (5 votes) ---------------------------- [LengthWhile until first duplication]\url{http://mathematica.stackexchange.com/questions/41469/lengt hwhile-until-first-duplication} I have the need to trim each of a large number of potentially very long lists (10^6+ elements) to the length where the last occurrence of any distinct element happens, or said another way, where the ... - asked by rasher (7 votes), answered by rasher (2 votes) ---------------------------- [Why do I get a different value when I change the order of integration?]\url{http://mathematica.stackexchange.com/questions/41454/why- do-i-get-a-different-value-when-i-change-the-order-of-integration} I think the following two-dimensional integrals should be equal, since they both integrate the function over the half plane defined by $t>\tau$. $$\int_{-\infty}^\infty \mathrm{d}t ... - asked by Jason B (7 votes), answered by Michael E2 (9 votes) ================================== Greatest hits from previous weeks: ================================== [How to get intersection values from a parametric graph?]\url{http://mathematica.stackexchange.com/questions/33947/how-to-get -intersection-values-from-a-parametric-graph} I have this graphed: ParametricPlot[{2.4*Cos[t] + 1.6*Cos[3 t/2], 2.4*Sin[t] - 1.6 Sin[3 t/2]}, {t, 0, 4*Pi}] It is a star, and the lines cross each other twice in the third quadrant. I need to ... - asked by guest (14 votes), answered by Artes (17 votes) ---------------------------- [Finding the best way to visualize rather complicated data]\url{http://mathematica.stackexchange.com/questions/33429/finding-the- best-way-to-visualize-rather-complicated-data} I have the following data data = {{7.5, 12.45, 12.45, 12.75, 12.75, 12.25, 12.25, 12.53, 12.53}, {8.5, 12.22, 12.22, 12.23, 12.23, 13, 13, 12.54, 12.54}, {9.5, 11.58, 11.53, 12.75, 13.48, 12.39, ... - asked by Vaggelis_Z (12 votes), answered by Pinguin Dirk (10 votes) ================================== Can you answer these? ================================== [Load a Mathematica Notebook using .Net code]\url{http://mathematica.stackexchange.com/questions/41410/load-a-mathe matica-notebook-using-net-code} I have gotten a tremendous amount of information from the question posted at (Load a Mathematica Package via .Net code), which my application is very similar to. Specifically in that thread, the ... - asked by Josh (1 vote) ---------------------------- [Trying to find the best Pade approximant for a given numer of terms]\url{http://mathematica.stackexchange.com/questions/41620/trying-to-f ind-the-best-pade-approximant-for-a-given-numer-of-terms} Let suppose that I have a function $f[x]$ I want to approximate using a Pade expansion and that I decide what would be maximum number of terms to be used. Is there any way with Mathematica to find ... - asked by Claude Leibovici (1 vote) ---------------------------- [Estimation of vector autoregressive (VAR) process]\url{http://mathematica.stackexchange.com/questions/41330/estimatio n-of-vector-autoregressive-var-process} To estimate 1-dimensional VAR process (which is AR process) you can easily use functions EstimatedProcess or FindProcessParameters like this: sample = RandomFunction[ARProcess[{.2,-.4},.1], {1,300}]; ... - asked by matt525252 (3 votes)
================================== Top new questions this week: ================================== [Why are numeric division and subtraction not handled better in Mathematica?]\url{http://mathematica.stackexchange.com/questions/40927/why- are-numeric-division-and-subtraction-not-handled-better-in-mathematica} There is something that has been troubling me for a while. At least in version 7, the performance of a / b and a - b is not equivalent to, and significantly inferior to, Divide[a, b] and Subtract[a, ... - asked by Mr.Wizard (37 votes) ---------------------------- [Cancellation of common terms]\url{http://mathematica.stackexchange.com/questions/41070/cancellatio n-of-common-terms} Can someone explain why the term A in case 2 does not get canceled out when case 1 does? I use "9.0 for Microsoft Windows (64-bit) (January 25, 2013)" case1 = A*(E^(-\[Lambda]) + \[Alpha]) == A; Simplify[case1, A ... - asked by user11946 (10 votes), answered by user11946 (2 votes) ---------------------------- [Plotting time data with axes labels and point labels]\url{http://mathematica.stackexchange.com/questions/41113/plotting-t ime-data-with-axes-labels-and-point-labels} I am trying to create a set of commands to automatically create clinical lab value plots. Using time is my major issue here. It is hard to dynamically reference the different point positions to ... - asked by James Wine (10 votes), answered by ubpdqn (6 votes) ---------------------------- [Is there a guideline about when to end expressions with semicolons?]\url{http://mathematica.stackexchange.com/questions/41086/is-th ere-a-guideline-about-when-to-end-expressions-with-semicolons} Whether for nested Ifs or within scoping constructs like Module and Block, I never know whether to end the final expression with a semicolon. I know the semicolon suppresses output, but, for example, ... - asked by acheong87 (10 votes), answered by Mr.Wizard (13 votes) ---------------------------- [How to efficiently mask an image?]\url{http://mathematica.stackexchange.com/questions/41125/how-to-eff iciently-mask-an-image} I want to extract/cut out a part of an image. Since my mask is not rectangular I want to set pixels that are not masked to zero (black). My current approach is something like this: img = ... - asked by chromate (9 votes), answered by Pickett (11 votes) ---------------------------- [Why is this code slow and how could I speed it up?]\url{http://mathematica.stackexchange.com/questions/41185/why-is-this-c ode-slow-and-how-could-i-speed-it-up} My goal is given an integer number to deduce if its digits increase (or remain the same) from left to right or not. Example: $1236, 123336$ are both considered numbers with increasing digits, but ... - asked by Zet (8 votes), answered by Kuba (13 votes) ---------------------------- [How is the mysterious Raw function used?]\url{http://mathematica.stackexchange.com/questions/40982/how-is-the- mysterious-raw-function-used} I have never seen an example use for the mysterious Raw function: Raw[h, "hexstring"] constructs a raw data object with head h, and with contents corresponding to the binary bit pattern ... - asked by Mr.Wizard (8 votes) ================================== Greatest hits from previous weeks: ================================== [How to play with Facebook data inside Mathematica?]\url{http://mathematica.stackexchange.com/questions/11673/how- to-play-with-facebook-data-inside-mathematica} I saw this post from Wolfram here and I would like to know how to import facebook data into Mathematica. - asked by Murta (20 votes), answered by Murta (24 votes) ---------------------------- [Is there an open source implementation of Mathematica-the-language?]\url{http://mathematica.stackexchange.com/questio ns/4454/is-there-an-open-source-implementation-of-mathematica-the-langua ge} I've seen questions before such as "What is the best open-source equivalent for Mathematica?", but that specific question (and that line of inquiry in general) cares more about the computer algebra ... - asked by sblom (46 votes), answered by Simon (39 votes) ================================== Can you answer these? ================================== [Poor CUDALink performance, when calling a kernel multiple times]\url{http://mathematica.stackexchange.com/questions/41102/poor-cudali nk-performance-when-calling-a-kernel-multiple-times} When working on a project of mine I noticed that CUDALink shows very poor performance when calling CUDA kernels multiple times in a loop-construct. To demonstrate this I put together this little ... - asked by definitely.uncertain (6 votes) ---------------------------- [Does Mathematica compute free-form-input on Wolfram servers?]\url{http://mathematica.stackexchange.com/questions/41238/does-mat hematica-compute-free-form-input-on-wolfram-servers} I've just started to use mathematica and I'm using the free-form input alot. The computation time for simple problems seems to take alot of time and my CPU isn't really used at all. I first thought ... - asked by qwertz (4 votes) ---------------------------- [Non linear model fit mathematica]\url{http://mathematica.stackexchange.com/questions/41017/non-l inear-model-fit-mathematica} I want to fit experimental data (temp,alpha) to the following equation for calculating k and Ea -Log[alpha]^n = function(k,Ea,temp) However i do not know exact value of "n". By this time i am ... - asked by Farrukh Shehzad (1 vote)
================================== Top new questions this week: ================================== [Moving maximum function?]\url{http://mathematica.stackexchange.com/questions/40526/moving- maximum-function} How can I construct a moving maximum function? For example, if I have a list of 12 values: { 5, 6, 9, 3, 2, 6, 7, 8, 1, 1, 4, 7 } and I want to maximize over 3 values then the expected result would ... - asked by Tyler Durden (11 votes), answered by rasher (16 votes) ---------------------------- [AndersonDarlingTest and DistributionFitTest Leaking Memory]\url{http://mathematica.stackexchange.com/questions/40661/andersonda rlingtest-and-distributionfittest-leaking-memory} I believe AndersonDarlingTest and probably all other tests are keeping a copy of data somewhere and not freeing it: Quit[]; (*Must be run in different cell*) $HistoryLength = 0; memdata = ... - asked by Ajasja (8 votes), answered by Ajasja (2 votes) ---------------------------- [Faster list duplicate 'limiter']\url{http://mathematica.stackexchange.com/questions/40765/faster- list-duplicate-limiter} Given some list, e.g., {5, 3, 2, 3, 1, 0, 1, 3, 5, 5, 4, 5, 1, 2, 5, 2, 2, 0, 1, 4}, I need to limit the duplicates, if any, to an arbitrarily chosen number. The excess duplicates are to be chopped ... - asked by rasher (7 votes), answered by rasher (4 votes) ---------------------------- [When does a list contain only ones?]\url{http://mathematica.stackexchange.com/questions/40670/when-does-a -list-contain-only-ones} I am starting with a list of length n that contains all -1's. For instance, when n = 6 the list is {-1, -1, -1, -1, -1, -1}. I pick a random integer from 1 to n and toggle the element by multiplying ... - asked by bobbym (7 votes), answered by rasher (6 votes) ---------------------------- [Converting StringJoin to StringForm inside Hold]\url{http://mathematica.stackexchange.com/questions/40628/converting-s tringjoin-to-stringform-inside-hold} Let's say I have a piece of code: Hold[{code1, "asdad " <> ToString[testa] <> " adsd " <> ToString[testb], code2}] (*MWE ofc*) which I want to convert. Each ... - asked by Kuba (7 votes), answered by Leonid Shifrin (8 votes) ---------------------------- [Graph databases / Nosql with Mathematica]\url{http://mathematica.stackexchange.com/questions/40731/graph -databases-nosql-with-mathematica} I am very new to mathematica but it looks like an interesting language and I would like to explore it for a future project to create a web search engine. It seems like it would be fairly well suited ... - asked by user2433617 (6 votes), answered by Mike Honeychurch (2 votes) ---------------------------- [Counting adjacent elements in a Matrix?]\url{http://mathematica.stackexchange.com/questions/40593/counting- adjacent-elements-in-a-matrix} To start, I have a situation where I have some matrix, for example $$ A=\left[ \begin{matrix} 4&2&2&3&3\\ 2&3&1&2&3\\ 3&0&4&0&4\\ ... - asked by Alizter (6 votes), answered by Rojo (3 votes) ================================== Greatest hits from previous weeks: ================================== [Automatic e-mail/text message when a calculation has finished?]\url{http://mathematica.stackexchange.com/questions/30167/automat ic-e-mail-text-message-when-a-calculation-has-finished} Sometimes Mathematica takes quite a while to finish calculations and it would be convenient to be able to move away from the computer while it is working. I was wondering if there is any "clever" hack ... - asked by Paco (36 votes), answered by rm -rf (41 votes) ---------------------------- [How to check if a 2D point is in a polygon?]\url{http://mathematica.stackexchange.com/questions/9405/how-to-ch eck-if-a-2d-point-is-in-a-polygon} Background: I use code from An Efficient Test For A Point To Be In A Convex Polygon Wolfram Demonstration to check if a point ( mouse pointer ) is in a ( convex ) polygon. Clearly this code fails for ... - asked by ndroock1 (42 votes), answered by kguler (30 votes) ================================== Can you answer these? ================================== [Schedule programing problem with integer linear programming]\url{http://mathematica.stackexchange.com/questions/40739/sched ule-programing-problem-with-integer-linear-programming} I know how to model this question on paper, but I don't know how doing it in Mathematica. Imagine , there is a university student who want to choose courses for this semester and he got the ... - asked by DSaad (4 votes) ---------------------------- [Cannot compile OpenGL code in Mathematica (vc2010-windows 8.1)]\url{http://mathematica.stackexchange.com/questions/40705/cannot-compi le-opengl-code-in-mathematica-vc2010-windows-8-1} LinkError of OpenGL My enviroment is windows 8.1 x64, Mathematica 9.0.1, opengl 1.1 targetDirectory = "E:\\Users\\Hyper\\Documents\\OpenGL"; sourceDirectory = ... - asked by HyperGroups (1 vote) ---------------------------- [BubbleChart bubble scale depends on y position]\url{http://mathematica.stackexchange.com/questions/40576/bubblech art-bubble-scale-depends-on-y-position} I noticed that the scaling of bubbles in the BubbleChart function depends on the y position of a bubble. Compare these two examples. BubbleChart[{{60.0, 20.0, 50.0}, {60.0, 90.0, 50.0}}, ... - asked by Jeff Lapides (1 vote)
================================== Top new questions this week: ================================== [Generating visually pleasing circle packs]\url{http://mathematica.stackexchange.com/questions/40334/generating- visually-pleasing-circle-packs} I would like to generate a circle pack that mimics this: (don't pay attention on numbers, and colors at all, at the moment I am interested in circle positions and radii only) or this: I am new ... - asked by VividD (23 votes), answered by Istvan Zachar (30 votes) ---------------------------- [Why do certain values in ArcSin not fully evaluate?]\url{http://mathematica.stackexchange.com/questions/40080/why-do- certain-values-in-arcsin-not-fully-evaluate} This is a continuation of: Why do certain fractional values in TriangleWave not evaluate? The analysis by R.M and rasher revealed that problem to reduce to the behavior of: ArcSin[Sin[Pi/ 10]] ... - asked by Mr.Wizard (14 votes), answered by Simon Woods (14 votes) ---------------------------- [More efficient way of generating list of occurrence counts?]\url{http://mathematica.stackexchange.com/questions/40377/more-effi cient-way-of-generating-list-of-occurrence-counts} Given a list, e.g., target = {a, b, c, b, c, d, c, d, e, f, a, h, g}, I want to generate a list containing the occurrence count of the corresponding element of the target list, e.g., {1, 1, 1, 2, 2, ... - asked by rasher (11 votes), answered by s0rce (7 votes) ---------------------------- [How to avoid an expensive subset of a Manipulate computation when dependent variables have not changed?]\url{http://mathematica.stackexchange.com/questions/40066/how-to-a void-an-expensive-subset-of-a-manipulate-computation-when-dependent-vari > } I have a Manipulate where a portion of the calculation that ends up displayed is dependent on a subset of the Manipulate control variables. It would make sense to cache that portion of the ... - asked by Peeter Joot (9 votes), answered by Nasser (8 votes) ---------------------------- [help to plot Poincare section for double pendulum]\url{http://mathematica.stackexchange.com/questions/40122/help-to- plot-poincare-section-for-double-pendulum} I am reading a book about classical mechanics. In the chapter about chaos, it gives the simplified and scaled equations for double pendulum as $$ \frac{d}{dt}\left[ \begin{matrix} \alpha \\[3mm] ... - asked by user1285419 (8 votes), answered by belisarius (5 votes) ---------------------------- [Another difference between Set and Setdelayed. Evaluation shortcut?]\url{http://mathematica.stackexchange.com/questions/40182/another -difference-between-set-and-setdelayed-evaluation-shortcut} A little while ago I wondered why f[x_] = f[x] gives an infinite iteration. I ended up discovering the following difference in evaluation between Set and SetDelayed with Evaluate. count = 0; ... - asked by Jacob Akkerboom (7 votes), answered by Jacob Akkerboom (1 vote) ---------------------------- [Arbitrary precision spline interpolation]\url{http://mathematica.stackexchange.com/questions/40163/arb itrary-precision-spline-interpolation} Current implementation of Interpolation does not allow arbitrary precision spline interpolation. Yu-Sung Chang say here that "it is not hard to implement it manually for arbitrary precision using ... - asked by Alexey Popkov (7 votes), answered by belisarius (3 votes) ================================== Greatest hits from previous weeks: ================================== [How can I improve Mathematica's resolution on a macbook retina display?]\url{http://mathematica.stackexchange.com/questions/18419/how-can- i-improve-mathematicas-resolution-on-a-macbook-retina-display} Mathematica looks a bit fuzzy on the retina screen, how can I increase the resolution? Here another screenshot showing a direct comparison between the browser and Mathematica - asked by Tom Wellington (32 votes), answered by programming_historian (14 votes) ---------------------------- [Reconstruct text pages cut by shredder]\url{http://mathematica.stackexchange.com/questions/32612/reconstr uct-text-pages-cut-by-shredder} Q1: I have a page of printed text file, but it was cut by a paper shredder (from top to bottom). You can download all the paper fragment here. There are some examples of them. How can I reconstruct ... - asked by mm.Jang (35 votes), answered by Kuba (31 votes) ================================== Can you answer these? ================================== [InverseFunction oddity]\url{http://mathematica.stackexchange.com/questions/40398/inversefun ction-oddity} InverseFunction[ConditionalExpression[#, 0 <= # <= 1] &] InverseFunction[ConditionalExpression[#, -1 <= # <= 1] &] The first line produces what I would expect: ... - asked by Will Vousden (4 votes) ---------------------------- [How to Check Spelling strings written inside input cells]\url{http://mathematica.stackexchange.com/questions/40199/how-to-chec k-spelling-strings-written-inside-input-cells} Is it possible to check the spelling of strings? Strings are often used to show messages in my user interfaces, and I would like to have an automatic checking. Methods that export all the strings to ... - asked by P. Fonseca (4 votes) ---------------------------- [Biorthogonal Projector Construction in Mathematica]\url{http://mathematica.stackexchange.com/questions/40294/biort hogonal-projector-construction-in-mathematica} (Note: This was originally posted on SE Mathematics, but I'm reposting it here as suggested by rm-rf, as I'm translating the theorem into Mathematica code to test it) I was trying to prove that the ... - asked by DumpsterDoofus (2 votes)
================================== Top new questions this week: ================================== [Create a torus with a hexagonal mesh for 3D-printing]\url{http://mathematica.stackexchange.com/questions/39879/creat e-a-torus-with-a-hexagonal-mesh-for-3d-printing} I am new to Mathematica, and I'm looking for a way to create patterns on the surface of 3D objects. One thing I have not been able to do is create a hexagonal mesh on a torus. What I would like to ... - asked by Manna (24 votes), answered by rm -rf (34 votes) ---------------------------- [Benchmarking Mathematica performance on the Raspberry Pi]\url{http://mathematica.stackexchange.com/questions/39684/benchmarking-m athematica-performance-on-the-raspberry-pi} It is not surprising that Mathematica on the Raspberry Pi is slow and clunky. In Stephen Wolfram's words, the command line is "quite zippy" but the notebook interface is "a trifle sluggish by modern ... - asked by bobthechemist (20 votes), answered by bobthechemist (22 votes) ---------------------------- [Fast DensityPlot]\url{http://mathematica.stackexchange.com/questions/39826/fast- densityplot} Is it possible to increase the perforamce the DensityPlot? For example, let's try to plot this "flower" f[x_, y_] := (x^2 + y^2) Exp[-x^2 - y^2] Sin[10 Sqrt[x^2 + y^2] + 10 ArcTan[x, y]]^4; ... - asked by ybeltukov (16 votes), answered by ybeltukov (14 votes) ---------------------------- [How to plot ternary density plots?]\url{http://mathematica.stackexchange.com/questions/39733/how-to-plo t-ternary-density-plots} How can I get a ternary density plot just like the plots from OriginLab? ContourPlot and DensityPlot seemingly can solve the [f,{x},{y}]-style, but cannot solve the [f,{x},{y},{z}]-style - asked by Scott Wang (15 votes), answered by Michael E2 (17 votes) ---------------------------- [Get tab key to indent a block of code]\url{http://mathematica.stackexchange.com/questions/39876/get-tab-key- to-indent-a-block-of-code} Is there some way I can change Mathematica keyboard behavior so I could select a block of text/code, press tab, and the selection would be indented to right? Similarly, I would like shift+tab to ... - asked by Murta (9 votes), answered by Leonid Shifrin (5 votes) ---------------------------- [Probability of the sum of the largest n samples]\url{http://mathematica.stackexchange.com/questions/39848/probabili ty-of-the-sum-of-the-largest-n-samples} 15 numbers are randomly chosen from U(0,1), what is the probability that the sum of largest four numbers is greater than 3.5? With[{f = OrderDistribution[{UniformDistribution[], 15}, #] &}, ... - asked by bobbym (9 votes), answered by belisarius (9 votes) ---------------------------- [Create a new infix operator]\url{http://mathematica.stackexchange.com/questions/39696/create-a -new-infix-operator} It is well known that the infix operator @@ is used as a short form of Apply. For example, both Apply[f,{a,b,c}] and f@@{a,b,c} return f[a,b,c]} Also the infix operator @@@ is used as a short form ... - asked by tchronis (8 votes), answered by Rojo (7 votes) ================================== Greatest hits from previous weeks: ================================== [How to find the phase difference of two sampled sine waves?]\url{http://mathematica.stackexchange.com/questions/11046/how-to-fin d-the-phase-difference-of-two-sampled-sine-waves} I'm trying to measure a phase difference between two Sine functions I've acquired with a computer. I'm uploading one of the .txt files with the data I'm working with here: txt file. To remove the ... - asked by Juan (19 votes), answered by bill s (18 votes) ---------------------------- [Finding the best way to visualize rather complicated data]\url{http://mathematica.stackexchange.com/questions/33429/finding-the- best-way-to-visualize-rather-complicated-data} I have the following data data = {{7.5, 12.45, 12.45, 12.75, 12.75, 12.25, 12.25, 12.53, 12.53}, {8.5, 12.22, 12.22, 12.23, 12.23, 13, 13, 12.54, 12.54}, {9.5, 11.58, 11.53, 12.75, 13.48, 12.39, ... - asked by Vaggelis_Z (12 votes), answered by Pinguin Dirk (10 votes) ================================== Can you answer these? ================================== [How can I take a function as data from a text field in order to plot it?]\url{http://mathematica.stackexchange.com/questions/39755/how-can-i-tak e-a-function-as-data-from-a-text-field-in-order-to-plot-it} I would like to create a window where a student may enter an equation and, by clicking on a button, the function gets plotted. (Quiero realizar una ventana en la cual el alumno tenga la opcion de ... - asked by Jenny Ojeda (1 vote) ---------------------------- [Want explanation of when different looping constructs are appropriate]\url{http://mathematica.stackexchange.com/questions/39704/want- explanation-of-when-different-looping-constructs-are-appropriate} For example when would you use a Do loop over a For loop? For which tasks would you use Map, Table, Scan, et cetera? I'm quite new to Mathematica and I don't really get what the advantages of any of ... - asked by Aron (1 vote) ---------------------------- [Error messages from NDSOlve]\url{http://mathematica.stackexchange.com/questions/39820/error-mes sages-from-ndsolve} I am trying to solve a boundary value problem with NDSolve. The code is: sol = Block[{M = 0.0}, NDSolve[{ f'''[x] + f[x]*f''[x] - f'[x]*f'[x] - M*f'[x] == 0, f[0] == 0, f'[0] == 1, f'[15] ... - asked by usman saeed (1 vote)
================================== Top new questions this week: ================================== [How to generate a random snowflake]\url{http://mathematica.stackexchange.com/questions/39361/how-to- generate-a-random-snowflake} 'Tis the season... And it's about time I posed my first question on Mathematica Stack Exchange. So, here's an holiday quest for you Graphics (and P-Chem?) gurus. What is your best code for generating ... - asked by Peltio (79 votes), answered by Silvia (107 votes) ---------------------------- [Exporting extremely large images; arrays generated via TensorProduct use 5 times as much RAM as expected?]\url{http://mathematica.stackexchange.com/questions/39412/exporti ng-extremely-large-images-arrays-generated-via-tensorproduct-use-5-times > } I am generating plots of the roots of certain classes of polynomials, in the spirit of the multicolored visuals on the Wiki page on algebraic numbers. I've thus far been able to make some extremely ... - asked by DumpsterDoofus (15 votes), answered by ybeltukov (11 votes) ---------------------------- [Plot discontinuous function with black and white disks marking discontinuities]\url{http://mathematica.stackexchange.com/questions/39445/p lot-discontinuous-function-with-black-and-white-disks-marking-discontinu ities} Let's say I'd like to plot Sign[x + 0.5]: Plot[Sign[x + 0.5], {x, -1, 1}] Mathematica will give this: This plot does not show very clearly the value of Sign[x + 0.5] at x = -0.5: is it 1? is ... - asked by user11426 (11 votes), answered by Michael E2 (15 votes) ---------------------------- [Zero-dimensional matrices]\url{http://mathematica.stackexchange.com/questions/39522/zero-dim ensional-matrices} In a recent Mathematica project, $(n \times 0)$- and $(0 \times n)$-dimensional matrices have suddenly become a frustratingly common edge case for me. For instance, consider the following two ... - asked by Eric Peterson (10 votes), answered by Michael E2 (4 votes) ---------------------------- [Can I return lists with different dimensions from a compiled function?]\url{http://mathematica.stackexchange.com/questions/39360/can-i-r eturn-lists-with-different-dimensions-from-a-compiled-function} Sometimes I'll need several lists with different dimensions to be returned by a compiled function, but compiled function will fail if an irregular list contained: (* The real case is of course much ... - asked by xzczd (10 votes), answered by Michael E2 (3 votes) ---------------------------- [Output from Wolfram language in Python]\url{http://mathematica.stackexchange.com/questions/39546/output-fro m-wolfram-language-in-python} I have a Python program which will run a script in the Wolfram language and then return to the main program. Is it possible to return values/variables to the main program? This is the code in Python ... - asked by Hamoudy (9 votes), answered by halirutan (14 votes) ---------------------------- [Is it Possible to change dashes into circles with Plot command?]\url{http://mathematica.stackexchange.com/questions/39394/is-it-po ssible-to-change-dashes-into-circles-with-plot-command} Is it possible to change the Dashed Style of a curve into circles with Plot command ? Plot[Cos[x], {x, 0, 2*Pi}, PlotStyle -> Directive[Dashed, Thickness[0.005]]] - asked by kamran (9 votes), answered by m_goldberg (4 votes) ================================== Greatest hits from previous weeks: ================================== [Are you interested in purchasing David Wagner's "Power programming with Mathematica"?]\url{http://mathematica.stackexchange.com/questions/16485/are -you-interested-in-purchasing-david-wagners-power-programming-with-mathe mat} I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about "Power programming with Mathematica" ... - asked by Todd Allen (98 votes), answered by Todd Allen (126 votes) ---------------------------- [Pick elements of largest absolute value]\url{http://mathematica.stackexchange.com/questions/31385/pick-elemen ts-of-largest-absolute-value} For example, given list = {{1, -3, -5}, {2, 1, 6}, {0, 2, 4}, {-9, 2, 6}} should return: {-5, 6, 4, -9} Updated I found a undocumented function called "Internal`MaxAbs",but it only accept two ... - asked by expression (16 votes), answered by Simon Woods (20 votes) ================================== Can you answer these? ================================== [How to extract structured array data from DefineDLLFunction in Mathematica]\url{http://mathematica.stackexchange.com/questions/39637/how-t o-extract-structured-array-data-from-definedllfunction-in-mathematica} I want to use my Bluechip PCI-ADC acquisition card in Mathematica via his dynamic link library Bcdll32.dll; (used to access functions on my PCI data acquisition cards). My problem is the function ... - asked by ROSU CONSTANTIN (3 votes) ---------------------------- [Return struct from function (with DownValues)]\url{http://mathematica.stackexchange.com/questions/39520/retur n-struct-from-function-with-downvalues} In Mathematica there is a way to create struct-like data type: struct[myField]=value I want to return myStruct from a function: getStruct[input_List] := Module[{struct}, (*populate ... - asked by EvgenijM86 (3 votes) ---------------------------- [Setting bash environment within external call]\url{http://mathematica.stackexchange.com/questions/39509/setting-bash -environment-within-external-call} I would like to run external command from Mathematica. For this I need to have bash environment configured via reading the content of ${HOME}/.bashrc file. When I execute the following code in ... - asked by mmal (1 vote)
================================== Top new questions this week: ================================== [Any ideas on how to use the Region` context?]\url{http://mathematica.stackexchange.com/questions/39184/any-idea s-on-how-to-use-the-region-context} If you type ?Region`* you'll get: which seems a bunch of interesting and not documented symbols. Any idea (or experience) on how to use them? Edit By using our "collective spelunking" I ... - asked by belisarius (23 votes), answered by m_goldberg (12 votes) ---------------------------- [How to create effect like Van Gogh's stroke brush?]\url{http://mathematica.stackexchange.com/questions/39003/how-to-cre ate-effect-like-van-goghs-stroke-brush} I need to apply Van Gogh's stroke brush effect to a random image Take the following image as an example: Thank you so much if you could help! - asked by user10495 (15 votes), answered by Simon Woods (15 votes) ---------------------------- [Elegant high precision `log1p`?]\url{http://mathematica.stackexchange.com/questions/39126/elegant- high-precision-log1p} Sometimes it is hard to understand how numerical expressions are evaluated. I remember reading claims by Wolfram on how smart the Kernel is to evaluate expressions trees numerically by recognizing ... - asked by alfC (12 votes), answered by Mark Adler (7 votes) ---------------------------- [Elegantly split a matrix into positive and negative parts?]\url{http://mathematica.stackexchange.com/questions/39113/elegantly- split-a-matrix-into-positive-and-negative-parts} I have a matrix $M$ of real components, and I want to split it into two matrices $M^+$ and $M^-$ of the same dimensions as $M$, where $M^+$ contains the positive components of $M$ (the remaining ... - asked by becko (12 votes), answered by Yves Klett (20 votes) ---------------------------- [Is there a difference between Divide[a,b] and a/b?]\url{http://mathematica.stackexchange.com/questions/39200/is-there-a-d ifference-between-dividea-b-and-a-b} In this comment it was asserted that Divide[a,b] and a/b are different, though the documentation indicates that they are the same. In particular, it was asserted that a/b is evaluated as a * 1/b, ... - asked by Mark Adler (10 votes), answered by Szabolcs (10 votes) ---------------------------- [How many Christmas gifts?]\url{http://mathematica.stackexchange.com/questions/39338/how-many-c hristmas-gifts} This question is based on the old song, The Twelve Days of Christmas In a comment made on a recent question, Yves Klett remarked, "no seasonal questions this year?" This reminded me of one I solved ... - asked by m_goldberg (8 votes), answered by rm -rf (13 votes) ---------------------------- [Which ColorFunction should I use to get such a gradient of blue-cyan-green-yellow-orange-red?]\url{http://mathematica.stackexchange.co m/questions/39300/which-colorfunction-should-i-use-to-get-such-a-gradien t-of-blue-cyan-green-yello} I want to get the effect in the above Figure. Here is my code: Plot3D[Log[ 4*((1 + x)^2)*(0.0065^2)*Log[y]/(3*((1 - 2 x))^2*(0.0267^2)) + 1]/ Log[y], {x, 0.315, 0.45}, {y, 0, 1}, Mesh -> ... - asked by Scott Wang (8 votes), answered by rm -rf (12 votes) ================================== Greatest hits from previous weeks: ================================== [List of compilable functions]\url{http://mathematica.stackexchange.com/questions/1096/list-of- compilable-functions} Is there somewhere a list on the functions that Compile can compile, or the cases in which a particular function can be compiled that I haven't found? I'd be glad even with a list of some of them ... - asked by Rojo (58 votes), answered by Oleksandr R. (66 votes) ---------------------------- [Can one identify the design patterns of Mathematica?]\url{http://mathematica.stackexchange.com/questions/24988/can- one-identify-the-design-patterns-of-mathematica} ... or are they unnecessary in such a high-level language? I've been thinking about programming style, coding standards and the like quite a bit lately, the result of my current work on a mixed ... - asked by Verbeia (65 votes), answered by Leonid Shifrin (50 votes) ================================== Can you answer these? ================================== [Efficient submatrix swaps for large sparse matrix]\url{http://mathematica.stackexchange.com/questions/39209/efficient- submatrix-swaps-for-large-sparse-matrix} I am implementing the 'swap' algorithm for a binary matrix to generate matrix permutations that maintain row and column totals. My problem is that my matrices are large and sparse (e.g., 19774 x 942, ... - asked by Gareth (1 vote) ---------------------------- [How to simplify expressions]\url{http://mathematica.stackexchange.com/questions/39341/how-t o-simplify-expressions} I read several similar posts but I have not found a solution yet. However, I think that my problem should be quite easy. So here we are. Relations Mt = M1 + M2; x1 = -(M2/Mt)*R; x2 = R*(1 - M2/Mt); ... - asked by Vaggelis_Z (1 vote) ---------------------------- [CountryData -> $Failed]\url{http://mathematica.stackexchange.com/questions/39110/countryda ta-failed} Today I started researching the "Four colours theorem" and to do so I need data, regions for example. I tried using the following line: CountryData["Ukraine", "Regions"] But the result: ... - asked by Vitaliy Sergeyevich Barash (1 vote)
================================== Top new questions this week: ================================== [How to plot contours in the faces of a cube]\url{http://mathematica.stackexchange.com/questions/38656/how-to-plot- contours-in-the-faces-of-a-cube} I'm trying to plot contours of a function f[x,y,z] on the faces of a cube as the example below, which represents the domain of this function. Is there a way to do it in Mathematica? The ... - asked by RaphaelDavid (25 votes), answered by belisarius (10 votes) ---------------------------- [Creating new graphics primitive (EdgeForm, FaceForm)]\url{http://mathematica.stackexchange.com/questions/38753/creatin g-new-graphics-primitive-edgeform-faceform} My question is strongly related to this question, nevertheless I would like to bring it to every ones attention. Lets say I want to create a new graphics primitive Boing which should look like this ... - asked by halirutan (23 votes), answered by Simon Woods (18 votes) ---------------------------- [Graphics elements do not line up perfectly in exported PDFs]\url{http://mathematica.stackexchange.com/questions/38745/graphics-ele ments-do-not-line-up-perfectly-in-exported-pdfs} Graphics elements do not always line up perfectly in exported PDFs. Take for example Graphics[{Point[{0, 1}], Line[{{0, 0}, {0, 1}}]}, AspectRatio -> Automatic] It looks like this on screen: ... - asked by Szabolcs (15 votes), answered by Szabolcs (13 votes) ---------------------------- [Drawing an arrow pointing at the "Enable Dynamics" button]\url{http://mathematica.stackexchange.com/questions/38692/drawing-an -arrow-pointing-at-the-enable-dynamics-button} Sometimes my students are given Mathematica notebooks as part of an assignment, and asked to go through some demonstrations contained in the .nb file. A lot of times I get complaints that the "graphs ... - asked by Steve D (11 votes), answered by Alexei Boulbitch (9 votes) ---------------------------- [ReplaceRepeated seemingly omits some rules]\url{http://mathematica.stackexchange.com/questions/38668/replacerepe ated-seemingly-omits-some-rules} Is there a simple way in Mathematica to prevent rule reordering? Let me give an example: a -> b //. {b -> c, (x_ -> y_) -> (x -> Expand[y])} (* a -> b *) though a -> b /. {b ... - asked by jondaman21 (10 votes), answered by Mr.Wizard (6 votes) ---------------------------- [Formatting Excel Borders with .Net]\url{http://mathematica.stackexchange.com/questions/38891/formatting-e xcel-borders-with-net} I have various tables generated in a Mathematica application and need to export this to MSExcel formatted in a specific way. The Excel formatting has to be generated by Mathematica. I am not ... - asked by BlueMac (9 votes), answered by WReach (11 votes) ---------------------------- [Problem with numerical evaluation of analytically solved integral, solution way off]\url{http://mathematica.stackexchange.com/questions/38734/problem-with- numerical-evaluation-of-analytically-solved-integral-solution-way} The following command in Version 9.0.1: N[Integrate[x^50*Sin[x], {x, 0, 1}]] gives $1.4615\times 10^{48}$ which is way off from the correct solution which is between $0$ and $0.5$. Interestingly ... - asked by vonjd (9 votes), answered by Szabolcs (12 votes) ================================== Greatest hits from previous weeks: ================================== [ShowLegend values]\url{http://mathematica.stackexchange.com/questions/6236/showlegend- values} How do I get ShowLegend to put the max and min values that a plot produces. for example, when using ListDensityPlot, with PlotRange->Automatic, the plot can sometimes clip. How do I get ... - asked by Andrew Spott (23 votes), answered by Jens (30 votes) ---------------------------- [Get a "step by step" evaluation in Mathematica]\url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (43 votes), answered by J.M. (38 votes) ================================== Can you answer these? ================================== [What are the limits of the Prime-functions?]\url{http://mathematica.stackexchange.com/questions/38819/ what-are-the-limits-of-the-prime-functions} Will Prime and PrimePi test up to 3 * 10^12? Where can I find the limits for these funtions? Also, what are the limits for PrimeOmega and PrimeNu? More generally, is there any documentation that gives ... - asked by martin (2 votes) ---------------------------- [Efficient storage of Kronecker sum of circulant matrices+diagonal matrix]\url{http://mathematica.stackexchange.com/questions/38901/efficient- storage-of-kronecker-sum-of-circulant-matricesdiagonal-matrix} I have a square matrix of the form $$M=D+\overset{N}{\underset{n=1}\bigoplus}R_n,$$ where $R_n$ are circulant matrices, $D$ is a diagonal matrix and $\oplus$ is Kronecker sum. Its size is quite big, ... - asked by Ruslan (2 votes) ---------------------------- [What is available for editing Mathematica source code with Emacs?]\url{http://mathematica.stackexchange.com/questions/38838/what-is-av ailable-for-editing-mathematica-source-code-with-emacs} I can find several Emacs libraries for Mathematica, but I'm not aware of a clear favourite, a definitive list, or of a library which is actively maintained and developed. None of these appear to be in ... - asked by Ian Hinder (6 votes)
================================== Top new questions this week: ================================== [Unexpected dots from Line]\url{http://mathematica.stackexchange.com/questions/38443/unexpected-d ots-from-line} I have noticed cases where Line produces dots in a graphics object when I think it shouldn't. The first of these is: Line[{{0., 0.}}] The second is: Line[{{0., 0.}, {0., 0.}}] Longer lists of ... - asked by m_goldberg (14 votes), answered by ybeltukov (3 votes) ---------------------------- [How to replace an element in a list based on the value of the next element?]\url{http://mathematica.stackexchange.com/questions/38472/how-to-r eplace-an-element-in-a-list-based-on-the-value-of-the-next-element} I use Mathematica a little bit. I try to understand it, but it is hard I have a list of 5 numbers selected randomly from 0 and -1. I have to replace a 0 with a 1 when the 0 is followed by -1. My ... - asked by user11021 (14 votes), answered by ybeltukov (14 votes) ---------------------------- [How to pick increasing numbers from the list]\url{http://mathematica.stackexchange.com/questions/38325/how-to-pick- increasing-numbers-from-the-list} How to pick increasing numbers from the list. lst = {5, 3, 6, 2, 7, 4, 8}; out: {5,6,7,8} So many interesting answers, is it possible know the index of result elements or position of ... - asked by Thomas (11 votes), answered by Simon Woods (6 votes) ---------------------------- [How to collect expressions from cells created by Print?]\url{http://mathematica.stackexchange.com/questions/38216/how-to-col lect-expressions-from-cells-created-by-print} I have a notebook where evaluation of a certain cell produced hundreds of adjacent output cells using Print. I need to create a list containing all expressions from those output cells as elements, and ... - asked by Vladimir Reshetnikov (11 votes), answered by belisarius (17 votes) ---------------------------- [How to constrain memory usage on HPC?]\url{http://mathematica.stackexchange.com/questions/38403/how-to-const rain-memory-usage-on-hpc} I found the performance of built-in function MemoryConstrained is very poor. It stops the evaluation after the memory already exceeds greatly than the values I set. There are several other questions ... - asked by matheorem (9 votes) ---------------------------- [Different results for integration using Mathematica and MATLAB]\url{http://mathematica.stackexchange.com/questions/38457/different- results-for-integration-using-mathematica-and-matlab} I have the following integration: $$\text{y}=2 \sqrt{\frac{1}{\pi }} \int_0^{\infty } \frac{e^{-z} \left(1-e^{-\frac{z}{b}} \left(\frac{a}{a+c z}\right)^L\right)}{\sqrt{z}} \, dz$$ I get different ... - asked by barznjy (9 votes), answered by Peltio (8 votes) ---------------------------- [Disconnected Frame/Axes in Plots]\url{http://mathematica.stackexchange.com/questions/38581/disconnecte d-frame-axes-in-plots} Is it possible to have "Tufte" style figure axes? That is so that the axes do not need to connect or span the entire data range? For an example of what I mean from the R's default histogram style: ... - asked by Gabriel (8 votes), answered by Silvia (6 votes) ================================== Greatest hits from previous weeks: ================================== [How to determine the center and radius of a circle given three points in 3D?]\url{http://mathematica.stackexchange.com/questions/16209/how-to-determ ine-the-center-and-radius-of-a-circle-given-three-points-in-3d} I was wondering if anyone could give me a hand with this problem I have. I have six points on a plane, and I am trying to determine if they form a circle or not. I know that any three points in 2D ... - asked by RedPotatoe (9 votes), answered by Mark McClure (15 votes) ---------------------------- [Get a "step by step" evaluation in Mathematica]\url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (43 votes), answered by J.M. (38 votes) ================================== Can you answer these? ================================== [Manipulating the pitch of a sound]\url{http://mathematica.stackexchange.com/questions/38423/manipulatin g-the-pitch-of-a-sound} After reading Manipulating a continuous stream of sounds I have to ask about controlling the frequency of a Sin sound in a continuous manner, with a Play inside a Manipulate, for example. The result ... - asked by Andrestand (3 votes) ---------------------------- [How to get vertices of a polytope given by equalities and inequalities?]\url{http://mathematica.stackexchange.com/questions/38414/how -to-get-vertices-of-a-polytope-given-by-equalities-and-inequalities} I have a polytope given by some equalities and inequalities, how can I get all the vertices of the polytope? If there's a way to deal with the one given by inequalities only, how can I reduce the ... - asked by Jason (3 votes) ---------------------------- [Solar system simulation (n-body physics) with OpenCL]\url{http://mathematica.stackexchange.com/questions/38478/solar-syst em-simulation-n-body-physics-with-opencl} I would like to simulate a n-body solar system in Mathematica. I have found the following example: ... - asked by shrx (1 vote)
================================== Top new questions this week: ================================== [Can Mathematica determine part-of-speech for each word in a text?]\url{http://mathematica.stackexchange.com/questions/38053/can-mathema tica-determine-part-of-speech-for-each-word-in-a-text} I've found that WordData has a database of English words and their possible parts of speech. But some words are ambiguous, e.g. result can be a verb or a noun: In[7]:= WordData["result", ... - asked by F'x (16 votes), answered by ssch (12 votes) ---------------------------- [Whether Wolfram Mathematica suits well for doing app in it instead of C++]\url{http://mathematica.stackexchange.com/questions/37888/whether-wolfr am-mathematica-suits-well-for-doing-app-in-it-instead-of-c} At uni I have an yearly essay. I'm allowed to use any technology for implementing it. I've been coding it in C++ with Qt. I thought of about Wolfram Mathematica because I have some expirience in it. ... - asked by gekannt (14 votes), answered by Murta (27 votes) ---------------------------- [How to enumerate all possible binary associations?]\url{http://mathematica.stackexchange.com/questions/37869/how -to-enumerate-all-possible-binary-associations} Suppose I have a list of symbols like: {a,b,c,d} I would like to enumerate all possible binary associations (combining symbols and/or sublists pairwise): {{{a,b},c},d} {{a,b},{c,d}} {a,{b,{c,d}}} ... - asked by Everett You (12 votes), answered by ybeltukov (11 votes) ---------------------------- [How to get list of duplicates when using DeleteDuplicates?]\url{http://mathematica.stackexchange.com/questions/37936 /how-to-get-list-of-duplicates-when-using-deleteduplicates} This might be easy, but can't find a way to use DeleteDuplicates to get also list of the actual duplicates. Example: lstA = {1, 2, 4, 4, 6, 7, 8, 8}; r = DeleteDuplicates[lstA] (* {1, 2, 4, 6, 7, ... - asked by Nasser (11 votes), answered by Mr.Wizard (13 votes) ---------------------------- [Raspberry Pi GPIO operations with Mathematica]\url{http://mathematica.stackexchange.com/questions/37926/raspb erry-pi-gpio-operations-with-mathematica} I started exploring GPIO operations on the RPi with Mathematica by following this brief tutorial which describes how to use DeviceWrite to cycle an LED on and off. A natural extension is to use ... - asked by bobthechemist (11 votes), answered by Daniel Chisholm (6 votes) ---------------------------- [Reduce can't reduce an equation without appropriate assumptions]\url{http://mathematica.stackexchange.com/questions/38118/reduc e-cant-reduce-an-equation-without-appropriate-assumptions} When the number of unknowns is three (x, y, z), Mathematica can solve it: Reduce[Abs[x] + Abs[y] + Abs[z] == 1 && z != 0, {x, y, z}, Reals, Backsubstitution -> True] for four variables ... - asked by expression (9 votes), answered by Artes (11 votes) ---------------------------- [Pasting monospaced text into Mathematica notebook destroys aligment]\url{http://mathematica.stackexchange.com/questions/38073/pasting- monospaced-text-into-mathematica-notebook-destroys-aligment} I drew the little ASCII-art electronics schema below in vim. When i try to paste it into a Mathematica notebook, with: A) A code cell B) A monospaced font (Courier New) Mathematica insists on ... - asked by blondiepassesby (9 votes), answered by WReach (11 votes) ================================== Greatest hits from previous weeks: ================================== [Mathematica9 linux version crash, how to fix it?]\url{http://mathematica.stackexchange.com/questions/17163/mathematica9- linux-version-crash-how-to-fix-it} Ubuntu 12.04 x86_64 kernel 3.2.0-35-generic Mathematica 9 linux version (x86_64) crashes with errors: X Error of failed request: BadGC (invalid GC parameter) Major opcode of failed request: ... - asked by goodluck (10 votes), answered by goodluck (14 votes) ---------------------------- [Calling MATLAB from Mathematica]\url{http://mathematica.stackexchange.com/questions/10231/calli ng-matlab-from-mathematica} How can I call MATLAB functions directly from Mathematica and transfer data/variables between the two systems? - asked by siva82kb (29 votes), answered by Szabolcs (35 votes) ================================== Can you answer these? ================================== [ParametricNDSolve and ProcessEquations]\url{http://mathematica.stackexchange.com/questions/37942/ parametricndsolve-and-processequations} I have a question regarding NDSolve`ProcessEquations and ParametricNDSolve. When using the regular NDSolve we have the option to divide the integration into the three steps ProcessEquations, Iterate ... - asked by jaclea (1 vote) ---------------------------- [How to set the working precision globally? $MinPrecision does not work]\url{http://mathematica.stackexchange.com/questions/38114/how-to-set-t he-working-precision-globally-minprecision-does-not-work} I want to increase the precision globally to 50 at least, but $MinPrecision does not work. $MinPrecision = 50; x = Sin[2.] (* -> 0.909297 *) Precision[x] (* -> MachinePrecision *) How to set ... - asked by renphysics (3 votes) ---------------------------- [matrix with IF/THEN condition]\url{http://mathematica.stackexchange.com/questions/37905/matrix- with-if-then-condition} How to generate all posible matrices with some conditions on the elements? I need to make for given $n$ all $n\times n$ matrices $A=(a_{ij})$ with three conditions: I. $a_{ij}=+1$ or $0$ or $-1$. ... - asked by aeiklmkv (1 vote)
================================== Top new questions this week: ================================== [Is Mathematica an Implementation of the Wolfram Language?]\url{http://mathematica.stackexchange.com/questions/37557/is-math ematica-an-implementation-of-the-wolfram-language} I am trying to figure out what the announcement of the Wolfram Language means for Mathematica. Is Mathematica an implementation of the Wolfram Language, or is it something else? - asked by Eric Brown (21 votes) ---------------------------- [How to plot a certain surface? What is its parametric equation?]\url{http://mathematica.stackexchange.com/questions/37698/how-to- plot-a-certain-surface-what-is-its-parametric-equation} The surface show below is very beautiful; however, I don't know its function either as an implicit function or in parametric form. Anyone have an idea about it and how to draw it with Mathematica? - asked by LCFactorization (14 votes), answered by kirma (35 votes) ---------------------------- [CompiledFunction returns machine numbers smaller than $MinMachineNumber]\url{http://mathematica.stackexchange.com/questions/37764 /compiledfunction-returns-machine-numbers-smaller-than-minmachinenumber> ) When thinking on the workaround for this LogLogPlot bug suggested by halirutan I noticed that CompiledFunction actually can return machine numbers smaller than $MinMachineNumber. Consider: f = ... - asked by Alexey Popkov (13 votes), answered by ybeltukov (12 votes) ---------------------------- [Laplace transform of $\frac{1-\cos (t)}{t}$]\url{http://mathematica.stackexchange.com/questions/37480/laplace- transform-of-frac1-cos-tt} In the documentation, it states that The Laplace transform of a function $f(t)$ is defined to be $\int_0^{\infty } f(t) e^{-s t} \, \mathrm{d}t$. But why can Mathematica not get the Laplace ... - asked by xslittlegrass (13 votes), answered by Vladimir Reshetnikov (17 votes) ---------------------------- [Why is multidimensional Reverse slow?]\url{http://mathematica.stackexchange.com/questions/37777/why-is-mult idimensional-reverse-slow} I have found that multidimensional Reverse is ~10 times slower than exact -1 ;; 1 ;; -1: n = 1000; mat = RandomReal[1, {n, n}]; mat2 = Reverse[mat, 2]; // AbsoluteTiming mat3 = mat[[All, -1 ;; 1 ;; ... - asked by ybeltukov (12 votes), answered by Mr.Wizard (3 votes) ---------------------------- [How can I remove the singleton dimensions of an array?]\url{http://mathematica.stackexchange.com/questions/37656/how-can-i- remove-the-singleton-dimensions-of-an-array} If I have an array A, for which Dimensions[A] is {9, 9, 1, 1, 3, 4}, how can I convert A' into an array with dimensions {9, 9, 3, 4}? I think there is a built-in function for this, but I can't ... - asked by LCFactorization (11 votes), answered by Simon Woods (10 votes) ---------------------------- [Concatenation of lists in a Fibonacci-like pattern]\url{http://mathematica.stackexchange.com/questions/37705/concatena tion-of-lists-in-a-fibonacci-like-pattern} I am trying to create a List of elements that follow the general pattern: $$X_{n+1} = X_n X_{n-1}$$ where the operation on the right hand side is concatenation, i.e., joining. I want to achieve the ... - asked by user106492 (10 votes), answered by Simon Woods (11 votes) ================================== Greatest hits from previous weeks: ================================== [Mathematica9 linux version crash, how to fix it?]\url{http://mathematica.stackexchange.com/questions/17163/mathematica9- linux-version-crash-how-to-fix-it} Ubuntu 12.04 x86_64 kernel 3.2.0-35-generic Mathematica 9 linux version (x86_64) crashes with errors: X Error of failed request: BadGC (invalid GC parameter) Major opcode of failed request: ... - asked by goodluck (9 votes), answered by goodluck (13 votes) ---------------------------- [How do I save a variable or function definition to a file?]\url{http://mathematica.stackexchange.com/questions/1959/how-do-i-sav e-a-variable-or-function-definition-to-a-file} Is it possible to save a function which was created via Interpolation of some data in such a way that I can use this function in a new Mathematica session without repeated interpolation of the data? ... - asked by partial81 (27 votes), answered by acl (24 votes) ================================== Can you answer these? ================================== [Plotting basin boundary]\url{http://mathematica.stackexchange.com/questions/37611/plotting -basin-boundary} How to plot the basin boundary in Mathematica? I have been trying to do this using the system y''[t] == -R y'[t] + (( Y[1] - y[t])/(Sqrt[(X[1] - x[t])^2 + (Y[1] - y[t])^2 + d^2])^3 ... - asked by HQH (1 vote) ---------------------------- [How do I use Greek characters in the WindowTitle option of CreateWindow?]\url{http://mathematica.stackexchange.com/questions/37635/how -do-i-use-greek-characters-in-the-windowtitle-option-of-createwindow} I am trying to write some exercises in Greek using CreateWindow. My problem is with using Greek characters in the option WindowTitle. For example, with CreateWindow[DocumentNotebook[{a}, WindowTitle ... - asked by kornaros (2 votes) ---------------------------- [Need help fixing fit, eliminating the error of property values assuming unconstrained model, and correcting script for an implicit function]\url{http://mathematica.stackexchange.com/questions/37570/need-hel p-fixing-fit-eliminating-the-error-of-property-values-assuming-unconstr> ) I fit some data with FindFit and NonlinearModelFit as well as obtained the parameter table and ANOVA table: data = {{82.5, 5.75}, {75, 5.965}, {68.75, 6}, {63.45, 6.01}, {58.95, 6.03}, {55, 6.04}}; ... - asked by chy (2 votes)
================================== Top new questions this week: ================================== [Even Fibonacci numbers]\url{http://mathematica.stackexchange.com/questions/37266/even-fibo nacci-numbers} Today, I found the Euler Project. Problem #2 is Each new term in the Fibonacci sequence is generated by adding the previous two terms. By starting with 1 and 2, the first 10 terms will be: 1, ... - asked by Tangshutao (19 votes), answered by rcollyer (28 votes) ---------------------------- [How to split list into disjoint lists?]\url{http://mathematica.stackexchange.com/questions/37249/how-to-spl it-list-into-disjoint-lists} I wonder if there is any simple way to split a list into its disjoint sublists, e.g. from list={{a,b},{e,f},{b,c},{c,d},{f,g,h}} get a result listdis={{{a,b},{b,c},{c,d}},{{e,f},{f,g,h}}}, so ... - asked by krzysiekb (13 votes), answered by Leonid Shifrin (11 votes) ---------------------------- [How to draw a spring?]\url{http://mathematica.stackexchange.com/questions/37207/how-to-dr aw-a-spring} I am new to Mathematica and have recently been exploring graphical animations. So I was experimenting with simple concepts in periodic motion and hence wondered how can I draw a simple spring? Is ... - asked by David McHarg (13 votes), answered by belisarius (11 votes) ---------------------------- [How to programmatically remove menu items]\url{http://mathematica.stackexchange.com/questions/36923/how-to-prog rammatically-remove-menu-items} I would like to do the opposite of what is described here. So rather than add a menu item I would like to programmatically remove one (or more). So given a knowledge of the structure of the menu *.tr ... - asked by Mike Honeychurch (9 votes) ---------------------------- [Impact Crater Simulation]\url{http://mathematica.stackexchange.com/questions/37183/impact -crater-simulation} I have been trying to model crater formation on a given planetary surface - $500\,\textrm{km}^2$. The locations of impacts are random, however, if an impact is within $30\,\textrm{km}$ of another, the ... - asked by Benjamin L (8 votes), answered by belisarius (6 votes) ---------------------------- [What is wrong with my expression for compiling?]\url{http://mathematica.stackexchange.com/questions/37262/what-i s-wrong-with-my-expression-for-compiling} Following code was translated from a snippet matlab code. Without compiling it worked slowly. I want to compile it, but am getting a numerical error. How do I compile this in a correct way? data = ... - asked by expression (7 votes), answered by ybeltukov (10 votes) ---------------------------- [how to simplify large expression with lots of special functions in it (BesselY, Hypergeometric, MeijerG etc...)]\url{http://mathematica.stackexchange.com/questions/37289/how-to-si mplify-large-expression-with-lots-of-special-functions-in-it-bessely} I saw this DE in Maple forum. When solving it using Mathematica 9.01, even though the result was correct (both solutions gave the same numerical answer for some random values), Mathematica's answer ... - asked by Nasser (7 votes), answered by ssch (1 vote) ================================== Greatest hits from previous weeks: ================================== [How can I improve Mathematica's resolution on a macbook retina display?]\url{http://mathematica.stackexchange.com/questions/18419/how-can- i-improve-mathematicas-resolution-on-a-macbook-retina-display} Mathematica looks a bit fuzzy on the retina screen, how can I increase the resolution? Here another screenshot showing a direct comparison between the browser and Mathematica - asked by Tom Wellington (28 votes), answered by programming_historian (11 votes) ---------------------------- [Where can I find examples of good Mathematica programming practice?]\url{http://mathematica.stackexchange.com/questions/18/where-can- i-find-examples-of-good-mathematica-programming-practice} I consider myself a pretty good Mathematica programmer, but I'm always looking out for ways to either improve my way of doing things in Mathematica, or to see if there's something nifty that I haven't ... - asked by J.M. (234 votes), answered by Faysal Aberkane (220 votes) ================================== Can you answer these? ================================== [The number of real values assumed by combinations of complex roots of a decic]\url{http://mathematica.stackexchange.com/questions/36933/the-number- of-real-values-assumed-by-combinations-of-complex-roots-of-a-decic} Define complex conjugate as the pair of complex numbers $a+bi,a-bi$. Assume you have 5 such pairs and they are the 10 roots $x_i$ of a 10th-deg equation with integer coefficients. In general, how many ... - asked by Tito Piezas III (1 vote) ---------------------------- [Odd colourization for FourierParameters. UI bug?]\url{http://mathematica.stackexchange.com/questions/37133/odd-colouriz ation-for-fourierparameters-ui-bug} The Mathematica UI colourizes the FourierParameters in the following Clear[x, y] g[x_, y_] = x^2 y ; f[x_, y_] = FourierSeries[x^2 y, {x, y}, {4, 4}, FourierParameters -> {1, 2 Pi}] as in the ... - asked by Peeter Joot (2 votes) ---------------------------- [Using FunctionExpand[] to evaluate symbolic derivatives]\url{http://mathematica.stackexchange.com/questions/37293/using -functionexpand-to-evaluate-symbolic-derivatives} Some symbolic derivatives of certain special function are not expanded automatically, but FunctionExpand often helps to get a derivative-free closed form expression. Derivative[1, 0][BesselJ][0, 1] ... - asked by Vladimir Reshetnikov (5 votes)
================================== Top new questions this week: ================================== [Kernel inexplicably hangs if I define a pure function without suppressing output]\url{http://mathematica.stackexchange.com/questions/35629/kernel-ine xplicably-hangs-if-i-define-a-pure-function-without-suppressing-output} Save any unsaved work before trying as it may crash Mathematica and other programs In v9.0.1.0 on OSX 10.8.5, if I start a new session and define two functions f1P = Sin[#^Sin[Sqrt[Gamma[#]]]] ... - asked by gpap (14 votes), answered by m_goldberg (4 votes) ---------------------------- [Bug in RepeatedNull?]\url{http://mathematica.stackexchange.com/questions/36850/bug -in-repeatednull} RepeatedNull appears to be buggy (version 8.0). Define f as follows: In[1]:= f@s:{h_@___...} := List @@@ s f is intended to accept (possibly empty) List of non-atomic (possibly empty) expressions ... - asked by Akater (13 votes), answered by m_goldberg (5 votes) ---------------------------- [Equivalent Nested Loop Structure]\url{http://mathematica.stackexchange.com/questions/35560/equival ent-nested-loop-structure} Consider the following examples: Flatten @ Table[ f[a, b, c], {a, 1, 3}, {b, 1, 3}, {c, 1, 3}] == f @@@ Tuples[ Range[3], 3] Flatten @ Table[ If[ a != b != c, f[a, b, c], Unevaluated[]], ... - asked by expression (12 votes), answered by Ray Koopman (2 votes) ---------------------------- [Finding the volume of a sphere using the Monte Carlo algorithm]\url{http://mathematica.stackexchange.com/questions/35683/finding -the-volume-of-a-sphere-using-the-monte-carlo-algorithm} I used the following code to find the volume of the sphere $x^2+y^2+z^2 = 1$ in the first octant: McVolume[Num_] := Module[{hit, miss, index, x, y, z}, hit = 0; miss = 0; For[index = 1, index ... - asked by johny (12 votes), answered by Szabolcs (15 votes) ---------------------------- [Making code version aware]\url{http://mathematica.stackexchange.com/questions/36806/making-code -version-aware} Mathics, a free Mathematica-compatible project has been recently launched. It provides a subset of the functions and capabilities of Mathematica at a slower pace. This opens us the tantalizing ... - asked by magma (11 votes), answered by magma (5 votes) ---------------------------- [Partitioning a list of numbers the Mathematica way]\url{http://mathematica.stackexchange.com/questions/36867/partitioning- a-list-of-numbers-the-mathematica-way} I have two sorted lists, one list will be called the "fences" and the other the "values" Fences could be: $\{1, 5, 9, 14\}$ Values could be $\{-1, 1, 3, 4, 6, 9, 10, 13, 14, 15\}$ I want to ... - asked by muzzlator (10 votes), answered by Ray Koopman (18 votes) ---------------------------- [Any way to make my equations look better, more Latex like?]\url{http://mathematica.stackexchange.com/questions/36697/any-way-to- make-my-equations-look-better-more-latex-like} I find that the equations I write in Mathematica are not always publication quality. Here is a typical example: If I copy as Latex, then I get the following code: \frac{\sum _{i=1}^N \frac{(k|k) ... - asked by Tyler Durden (9 votes), answered by Mike Honeychurch (9 votes) ================================== Greatest hits from previous weeks: ================================== [How to manipulate 2D plots?]\url{http://mathematica.stackexchange.com/questions/7142/how-to-mani pulate-2d-plots} When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ... - asked by Istvan Zachar (58 votes), answered by Istvan Zachar (56 votes) ---------------------------- [Programmatic approach to HDR photography with Mathematica image processing functions]\url{http://mathematica.stackexchange.com/questions/9342/programm atic-approach-to-hdr-photography-with-mathematica-image-processing-funct > } The High dynamic range imaging (HDR or HDRI) direction in photography and image processing became very popular recently. Besides obvious photo art applications (see examples), there are many great ... - asked by Vitaliy Kaurov (44 votes), answered by Simon Woods (30 votes) ================================== Can you answer these? ================================== [How can I set constraints on parameters in NelderMeadMinimize package?]\url{http://mathematica.stackexchange.com/questions/35651/how-can- i-set-constraints-on-parameters-in-neldermeadminimize-package} I read about NelderMeadMinimize package. How can I set constraints on the parameters? For example I want to minimize an equation with 10 parameters such as {a1, a2, ....}. I want to put the condition ... - asked by Soodeh Z. (1 vote) ---------------------------- [WhenEvent method with 3 conditions]\url{http://mathematica.stackexchange.com/questions/36869/whenev ent-method-with-3-conditions} I am trying to solve system of differential equations below $x''(t)=-2.25cos(1.5t)-x(t)-x'(t)$ $y''(t)=-1.125cos(1.5t)-4y(t)-y'(t)$ for $x>(1+y)$ then $z'(t)=x(t)-(1+y(t))$ for $|x|<(1+y)$ ... - asked by Dadan Ari Wibowo (1 vote) ---------------------------- [Caching data in Mathematica package]\url{http://mathematica.stackexchange.com/questions/36875/caching-d ata-in-mathematica-package} Consider the following: m=Quantity[1,"meter"] If I run the package, it will return 1m But when I load the package, the package is re-evaluated meaning, that internet i required. Is it possible to ... - asked by OskarNS (1 vote)
================================== Top new questions this week: ================================== [Incorrect result from Integrate]\url{http://mathematica.stackexchange.com/questions/35324/incorre ct-result-from-integrate} I attempted to calculate the following integral: Integrate[ Sqrt[x] Exp[-(x - a)^2], {x, 0, Infinity}, Assumptions -> a > 0] 1/(4 Sqrt[a])I E^(-(a^2/2)) Pi( a^2 BesselI[-(1/4), a^2/2] - (1 + a^2) ... - asked by DumpsterDoofus (12 votes), answered by Michael E2 (10 votes) ---------------------------- [Unpacked eigenvectors of complex matrices]\url{http://mathematica.stackexchange.com/questions/35266/unpacked -eigenvectors-of-complex-matrices} I want to calculate eigenvectors of a Hermitian matrix. For example $HistoryLength = 0; n = 3000; mat = # + ConjugateTranspose[#] &@RandomComplex[{0, 1 + I}, {n, n}]; evec = Eigenvectors[mat]; ... - asked by ybeltukov (11 votes), answered by halirutan (8 votes) ---------------------------- [Wrong numerical value while exporting to a JSON string]\url{http://mathematica.stackexchange.com/questions/35165/wrong-nume rical-value-while-exporting-to-a-json-string} The following code: ExportString[{"a" -> 2000000., "b" -> 0.000001}, "JSON"] Gives the results {"a" : 2.e60, "b" : 1.e-6} The first one is obviously having a wrong numerical value. Also, ... - asked by hwlau (11 votes), answered by hwlau (6 votes) ---------------------------- [Boundary effect of Graphics3D object Tube[]]\url{http://mathematica.stackexchange.com/questions/35331/boundary-e ffect-of-graphics3d-object-tube} I draw a Graphics3D object of two tubes: Graphics3D[{Tube[{{-0.2, -1, 0}, {-0.2, 1, 0}}, 0.05], Tube[{{0, 0, -1}, {0, 0, 1}}, 0.05]}, Boxed -> False] And I get this: Now I want to have ... - asked by 9527 (10 votes), answered by ybeltukov (10 votes) ---------------------------- [Monitoring progress of long calculations]\url{http://mathematica.stackexchange.com/questions/35139/moni toring-progress-of-long-calculations} I've came upon a few methods of how to display "processing" information while Mathematica is running. But, from what I've understood, this only works in between lines of codes. Is it possible to ... - asked by Gabriel (10 votes), answered by Simon Woods (8 votes) ---------------------------- [How to find a specific color in one picture?]\url{http://mathematica.stackexchange.com/questions/35132/how-to-f ind-a-specific-color-in-one-picture} In a picture, there are many different colors. How can I just want to find the position of one color. In the following picture, if I would like to find the coordinates of the position of blue, how can ... - asked by KathyLL (9 votes), answered by cormullion (12 votes) ---------------------------- [Is there a way to make the "Details" section of the documentation expand by default?]\url{http://mathematica.stackexchange.com/questions/35370/is-there -a-way-to-make-the-details-section-of-the-documentation-expand-by-defa} By default, the Mathematica documentation opens with the "Details" section collapsed. This is never what I'm looking for in fact, I've lost count of the times I've sought help on a feature and ... - asked by raxacoricofallapatorius (8 votes) ================================== Greatest hits from previous weeks: ================================== [xkcd-style graphs]\url{http://mathematica.stackexchange.com/questions/11350/xkcd-style -graphs} I received an email to which I wanted to respond with a xkcd-style graph, but I couldn't manage it. Everything I drew looked perfect, and I don't have enough command over PlotLegends to have these ... - asked by Amatya (392 votes), answered by Simon Woods (261 votes) ---------------------------- [Can one identify the design patterns of Mathematica?]\url{http://mathematica.stackexchange.com/questions/24988/can- one-identify-the-design-patterns-of-mathematica} ... or are they unnecessary in such a high-level language? I've been thinking about programming style, coding standards and the like quite a bit lately, the result of my current work on a mixed ... - asked by Verbeia (52 votes), answered by Leonid Shifrin (43 votes) ================================== Can you answer these? ================================== [Problem in exporting a plot with background to pdf]\url{http://mathematica.stackexchange.com/questions/35131/problem-in-ex porting-a-plot-with-background-to-pdf} Just wondering if someone could help me for this problem. I have utilised prolog to use a jpg image as the background of my plot in order to compare my results with a reference plot. Although the ... - asked by mak maak (1 vote) ---------------------------- [Series expansion: Taylor series takes huge amount of time]\url{http://mathematica.stackexchange.com/questions/35372/series-expan sion-taylor-series-takes-huge-amount-of-time} I'm working on a notebook, trying to expand the root of a cubic polynomial in Taylor series. When I type: Series[(Sqrt[46656 a^2 - 864 (3 2^(1/3) a^(2/3) + 2 a B)^3] + 216 a)^(1/3) , {a, 0, 2}] ... - asked by user10387 (2 votes) ---------------------------- [How to define tensor fields in Mathematica?]\url{http://mathematica.stackexchange.com/questions/35374/how- to-define-tensor-fields-in-mathematica} I am wondering if the is any (neat) way to define tensor fields in Mathematica. Let me be more specific, using an example: For instance a tensor W with 3 indices, which is anti symmetric in the first ... - asked by user10389 (1 vote)
================================== Top new questions this week: ================================== [Nice formatting for the results of a dice game simulation]\url{http://mathematica.stackexchange.com/questions/34861/nice-f ormatting-for-the-results-of-a-dice-game-simulation} One of my Mathematica interests is in problems related to the formatting of output. Getting nice formatting from Mathematica is often frustrating, but occasionally Mathematica will delight me by ... - asked by m_goldberg (22 votes), answered by ssch (16 votes) ---------------------------- [Export Code to Pseudocode?]\url{http://mathematica.stackexchange.com/questions/34997/expor t-code-to-pseudocode} I'm writing a paper and all my code is in Mathematica. The snippets are mostly simple, and consist of loops, maps, variables, and conditionals. I'd like add it to my paper, however, not many academic ... - asked by M.R. (13 votes) ---------------------------- [How to efficiently find moments of a multinormal distribution?]\url{http://mathematica.stackexchange.com/questions/34779/how -to-efficiently-find-moments-of-a-multinormal-distribution} I have a multinormal distribution with covariance matrix $\sigma$ and zero mean. I want to find moment $$ E[x_1^{r_1}x_2^{r_2}\cdots x_n^{r_n}] =\,? $$ Of course, there is a build-in function ... - asked by ybeltukov (9 votes), answered by ybeltukov (9 votes) ---------------------------- [Problem importing a JCAMP-DX mass spectral file]\url{http://mathematica.stackexchange.com/questions/34624/problem-impo rting-a-jcamp-dx-mass-spectral-file} I have some problems importing a JCAMP-DX EI-mass spectral file using Mathematica 9. For example, if I download the mass spectrum of nonacosane in JCAMP format from NIST, ... - asked by Tom Wenseleers (8 votes), answered by Sjoerd C. de Vries (8 votes) ---------------------------- [How to partition a list of numbers in two lists of numbers such that each lists elements sums up to the same number?]\url{http://mathematica.stackexchange.com/questions/34952/how-to-pa rtition-a-list-of-numbers-in-two-lists-of-numbers-such-that-each-lists} I have the following list of squares. {1, 4, 9, 16, 25, 36, 49, 64, 81, 100, 121, 144, 169, 196, 225, 256} Their sum is $1496$, I want to make two partitions with the given numbers and each ... - asked by Gustavo Bandeira (7 votes), answered by Daniel Lichtblau (8 votes) ---------------------------- [finding anagrams]\url{http://mathematica.stackexchange.com/questions/34720/finding- anagrams} What I'm trying to find are the 4 letter words in the mathematica dictionary that have the most anagrams and the amount of anagrams these have each. But I can't seem to find all the 4 letter words in ... - asked by jas (7 votes), answered by rcollyer (7 votes) ---------------------------- [How can I scale a plot in vector graphic or PDF form?]\url{http://mathematica.stackexchange.com/questions/34909/how-can-i-s cale-a-plot-in-vector-graphic-or-pdf-form} I am not at all a computer graphics expert, but it seems that portable document format (PDF) files have a "native size," even though they may (and usually do!) contain vector graphics that can be ... - asked by Andrew (6 votes), answered by Alexey Popkov (4 votes) ================================== Greatest hits from previous weeks: ================================== [Mathematica9 linux version crash, how to fix it?]\url{http://mathematica.stackexchange.com/questions/17163/mathematica9- linux-version-crash-how-to-fix-it} Ubuntu 12.04 x86_64 kernel 3.2.0-35-generic Mathematica 9 linux version (x86_64) crashes with errors: X Error of failed request: BadGC (invalid GC parameter) Major opcode of failed request: ... - asked by goodluck (9 votes), answered by goodluck (13 votes) ---------------------------- [Finding all simple paths between two vertices in a graph]\url{http://mathematica.stackexchange.com/questions/25779/finding-all -simple-paths-between-two-vertices-in-a-graph} There are built-in methods to find a shortest path between two vertices in a graph, and the question on finding all shortest paths between two vertices has gathered quite a bit of attention. A path ... - asked by mrm (9 votes), answered by trybik (8 votes) ================================== Can you answer these? ================================== [Visualizing nested lists for easier human understanding]\url{http://mathematica.stackexchange.com/questions/34651/vis ualizing-nested-lists-for-easier-human-understanding} When interacting with Mathematica, I often find myself staring blankly at waves of curly braces, trying to understand how data is organized hierarchically. For example, the beginning of the result to ... - asked by duozmo (3 votes) ---------------------------- [how to load packages on local computer when using remote kernels]\url{http://mathematica.stackexchange.com/questions/34966/how-to-lo ad-packages-on-local-computer-when-using-remote-kernels} I usually works remotely using kernels on our hpc and front-end on my local laptop. This enable me do relatively large computation within my laptop(IP address of my laptop may change frequently). But ... - asked by xslittlegrass (1 vote) ---------------------------- [Strange behaviour of Internal`InheritedBlock]\url{http://mathematica.stackexchange.com/questions /34698/strange-behaviour-of-internalinheritedblock} I was going to post an answer for fast way to replace all zeros in the matrix. I was even quite happy because timings were the same order of magnitude as others. The idea was to overwrite Identity: ... - asked by Kuba (4 votes)
================================== Top new questions this week: ================================== [How to remap a fisheye image?]\url{http://mathematica.stackexchange.com/questions/34264/how-to-rem ap-a-fisheye-image} I want to flatten a series of fisheye images by remapping them to a rectinlinear projection. To achieve this, I need to be able to remap the pixels of the image using fisheye correction formulas for ... - asked by ErikP (10 votes), answered by Simon Woods (9 votes) ---------------------------- [Using With to scope over pure functions]\url{http://mathematica.stackexchange.com/questions/34345/using-w ith-to-scope-over-pure-functions} Consider this example: given an option for a function func as "x" :> (a&), how can one assign different values to a locally inside func? a = False; (* global value of a *) func[opt_] := ... - asked by Istvan Zachar (10 votes), answered by Rojo (12 votes) ---------------------------- [How do I place a texture on an irregular 3D model?]\url{http://mathematica.stackexchange.com/questions/34144/how-do-i-p lace-a-texture-on-an-irregular-3d-model} I'm trying to reproduce a textured head in Mathematica, and I'm using a kind of 'net' of a head which contains all the features on the face. The texture looks like this: which is supposed to look ... - asked by user10035 (9 votes), answered by Sjoerd C. de Vries (2 votes) ---------------------------- [Finding a point from a set of contours such that it is nearest to a given point]\url{http://mathematica.stackexchange.com/questions/34204/finding-a-p oint-from-a-set-of-contours-such-that-it-is-nearest-to-a-given-point} I have several contour lines and one point. How can I find a point in one of those contour lines which is nearest to the given point? (*Create the implicit curves*) ... - asked by c_susetyo (9 votes), answered by PlatoManiac (11 votes) ---------------------------- [Organise a graph's vertices into levels]\url{http://mathematica.stackexchange.com/questions/34106/organise-a -graphs-vertices-into-levels} I would like to organise a graph's vertices in levels. Consider g = { 0 -> 1, 1 -> 2, 2 -> 3, 0 -> 4, 0 -> 5, 2 -> 6, 2 -> 7, 8 -> 3, 4 -> 9, 5 -> 9, 6 -> 9, 6 ... - asked by (7 votes), answered by ybeltukov (6 votes) ---------------------------- [Limit of sequence of functions behaving strange]\url{http://mathematica.stackexchange.com/questions/34124/limit-of- sequence-of-functions-behaving-strange} I'm trying to determine the limit of the sequence of functions $$f_n(x)=\left(\frac{1}{\pi}\arctan(n x) + 1/2\right)^n. $$ I define f[x_, n_] := (1/2 + ArcTan[n x]/Pi)^n And enter Limit[f[x, ... - asked by Isak Kupersmidt (7 votes) ---------------------------- [Extract urls from list]\url{http://mathematica.stackexchange.com/questions/34484/extract-urls -from-list} If I have a list like list = {"my element 1 http://link.com", "http://link2.com my element 2"} how do I get a list of the links inside each element? Something like StringCases[list, "http" ~~ ... - asked by su1 (6 votes), answered by Yves Klett (9 votes) ================================== Greatest hits from previous weeks: ================================== [Are you interested in purchasing David Wagner's "Power programming with Mathematica"?]\url{http://mathematica.stackexchange.com/questions/16485/are -you-interested-in-purchasing-david-wagners-power-programming-with-mathe mat} I recently contacted McGraw-Hill to see if they have a mechanism in place for printing out-of-print books that are still of interest. Specifically, I asked about "Power programming with Mathematica" ... - asked by Todd Allen (92 votes), answered by Todd Allen (119 votes) ---------------------------- [How to create new "person curve"?]\url{http://mathematica.stackexchange.com/questions/17704/how-to-cr eate-new-person-curve} Wolfram|Alpha has a whole collection of parametric curves that create images of famous people. To see them, enter WolframAlpha["person curve"] into a Mathematica notebook, or person curve into ... - asked by Simon (41 votes), answered by Vitaliy Kaurov (14 votes) ================================== Can you answer these? ================================== [Exporting graphics to PDF results in destroyed fonts on Windows 8]\url{http://mathematica.stackexchange.com/questions/34303/exporting-graph ics-to-pdf-results-in-destroyed-fonts-on-windows-8} Executing plot = Plot[x^2, {x, 0, 100}, PlotLabel -> "Plot"]; SetDirectory[NotebookDirectory[]]; Export["plot.pdf", plot, "PDF"]; results in Is this a bug? OS is Windows 8, 64bit. - asked by Frederik Ziebell (1 vote) ---------------------------- [TableHeading Lines Do Not Show Up]\url{http://mathematica.stackexchange.com/questions/34287/tableheading-l ines-do-not-show-up} For a list list = {{"a", "b", "c"}, {"d", "e"}}; Table heading lines do not show up TableForm[list, TableHeadings -> Automatic] But it works if the list list = {{"a", "b", "c"}, {"d", "e", ... - asked by Deco (2 votes) ---------------------------- [Syntax for FrontEnd`SelectionSetStyle]\url{http://mathematica.stackexchange.com/questi ons/34297/syntax-for-frontendselectionsetstyle} I know FrontEnd`SelectionSetStyle is undocumented, but its name suggests it does what I need. What is its syntax? I have already tried several variations of the following button on some selected code ... - asked by Hector (2 votes)
================================== Top new questions this week: ================================== [Strip waste braces in nested list]\url{http://mathematica.stackexchange.com/questions/33837/strip-waste- braces-in-nested-list} I have nested lists wherein there are a lot of waste levels which looks like l = {{{{{{2, 2}}, 3}, 2, {{2, 33}}, 4, 5}}}; I would like to reduce it to somthing like l = {{{2, 2}, 3}, 2, {2, 33}, ... - asked by (16 votes), answered by Leonid Shifrin (19 votes) ---------------------------- [How to get intersection values from a parametric graph?]\url{http://mathematica.stackexchange.com/questions/33947/how-to-get -intersection-values-from-a-parametric-graph} I have this graphed: ParametricPlot[{2.4*Cos[t] + 1.6*Cos[3 t/2], 2.4*Sin[t] - 1.6 Sin[3 t/2]}, {t, 0, 4*Pi}] It is a star, and the lines cross each other twice in the third quadrant. I need to ... - asked by guest (14 votes), answered by Artes (17 votes) ---------------------------- [Mathematica gives wrong result while Wolfram|Alpha is correct]\url{http://mathematica.stackexchange.com/questions/33866/mathemati ca-gives-wrong-result-while-wolframalpha-is-correct} Why does Mathematica and Wolfram|Alpha give different results based upon the same code? I know Wolfram|Alpha's 7.85 is correct. - asked by dansu (11 votes), answered by Michael E2 (12 votes) ---------------------------- [Replace elements in list not matching elements of another list at the same position]\url{http://mathematica.stackexchange.com/questions/33731/replace- elements-in-list-not-matching-elements-of-another-list-at-the-same-posit > } I would like to compare two arrays: m = {a,b,c,d,d,f}; n = {b,b,a,d,d,e}; and get: {0,b,0,d,d,0} I have tried all kinds of things, like: m = {a,b,c,d,d,f}; n = {b,b,a,d,d,e}; Transpose[{m, ... - asked by martin (11 votes), answered by Leonid Shifrin (18 votes) ---------------------------- [How can I type-check the arguments of a Mathematica function?]\url{http://mathematica.stackexchange.com/questions/33884/how-can -i-type-check-the-arguments-of-a-mathematica-function} (For educational purposes) I defined the following functions: Translation (in $\mathbb{R}^2$): trM[vec_] := {{1, 0, vec[[1]]}, {0, 1, vec[[2]]}, {0, 0, 1}} Rotation (in $\mathbb{R}^2$): ... - asked by ndroock1 (10 votes), answered by RunnyKine (6 votes) ---------------------------- [How to bend a logarithmic number line into a circle]\url{http://mathematica.stackexchange.com/questions/33924/how-to-ben d-a-logarithmic-number-line-into-a-circle} One way to plot a sequence of numbers on a logarithmic number line is this: LogLogPlot[0, {t, 8, 16}, Axes -> {True, False}, Ticks -> {{8, 9, 10, 11, 12, 13, 14, 15, 16}}] How can the ... - asked by Bogdan (9 votes), answered by ybeltukov (4 votes) ---------------------------- [Is there a way to find out who is importing a package?]\url{http://mathematica.stackexchange.com/questions/33949/is-there -a-way-to-find-out-who-is-importing-a-package} After calling some functions, if I look into $ContextPath, I can see that JLink` is in there. Is there a way to find out what sequence of functions calls (like a stack-trace) imported a particular ... - asked by Adal (9 votes), answered by Leonid Shifrin (8 votes) ================================== Greatest hits from previous weeks: ================================== [How can I extract data points from a black and white image?]\url{http://mathematica.stackexchange.com/questions/3831/how-can-i-e xtract-data-points-from-a-black-and-white-image} Consider the following graph (source): Is there any way to extract the data points from this image in a semi-automatic way? I have seen, and tried the methods suggested in this question, but they ... - asked by Eli Lansey (29 votes), answered by Sjoerd C. de Vries (33 votes) ---------------------------- [Finding the centroid of the area between two curves]\url{http://mathematica.stackexchange.com/questions/17170/finding-th e-centroid-of-the-area-between-two-curves} When I have an area bounded by curves, is there a built-in way to find the center of the area? Or do I have to plot it first and then use ComponentMeasurements on it? For example: the area under $y= ... - asked by a3f (10 votes), answered by george2079 (3 votes) ================================== Can you answer these? ================================== [How can I find the source of a memory leak?]\url{http://mathematica.stackexchange.com/questions/33707/how-can-i-f ind-the-source-of-a-memory-leak} I found a really weird issue using NDSolve`ProcessEquations inside module. We start by setting HistoryLength to 0. After this we define a function which takes in an integer and creates a Table of ... - asked by jaclea (4 votes) ---------------------------- [Is there something like MaxProcessorUsed?]\url{http://mathematica.stackexchange.com/questions/33775 /is-there-something-like-maxprocessorused} For standard procedures it is easy to test if the implementation is better or worse than other by using Timing etc. It does not help us with creating Dynamic interfaces/visualisations. Sometimes it ... - asked by Kuba (5 votes) ---------------------------- [How does Mathematica estimate error on fit parameters?]\url{http://mathematica.stackexchange.com/questions/33685/how-d oes-mathematica-estimate-error-on-fit-parameters} When performing a fit using NonlinearModelFit (or any of Mathematica fitting functions, but I am particularly interested in nonlinear models), Mathematica makes a covariance matrix available for all ... - asked by ydl (1 vote)
================================== Top new questions this week: ================================== [Compiling ColorFunction for faster complex phase-amplitude plots]\url{http://mathematica.stackexchange.com/questions/32977/compiling-c olorfunction-for-faster-complex-phase-amplitude-plots} I have gotten into the habit of plotting complex-valued functions on a plane using a color-function along the lines of Function[{z}, Hue[Arg[z]/(2 Pi), 1, Abs[z]]]. For example, the following code ... - asked by user93655 (16 votes), answered by halirutan (15 votes) ---------------------------- [Pattern to match L, but not L[_]]\url{http://mathematica.stackexchange.com/questions/33025/pattern-to-m atch-l-but-not-l} I have an expression where I want to replace L but not L[_] For example, the following doesn't work and sub = {L :> 2}; L + L[tilde] /. sub (* 2 + 2[tilde], but I want 2 + L[tilde]*) Is there ... - asked by jlperla (13 votes), answered by Szabolcs (20 votes) ---------------------------- [Is there a Mathematica barcode reader?]\url{http://mathematica.stackexchange.com/questions/33093/is-there- a-mathematica-barcode-reader} Is there a Mathematica barcode image reader (much like TextRecognize) that allows the user to enter an image of a barcode and then read it to get an output string? - asked by David G. Stork (12 votes), answered by belisarius (13 votes) ---------------------------- [How to enlarge $\it{Mathematica}$'s knowledge about certain functions?]\url{http://mathematica.stackexchange.com/questions/33251/how-to -enlarge-itmathematicas-knowledge-about-certain-functions} I'm often troubled with the following task. I need to carry out symbolical computations involving certain special functions. Let me take as an example Barnes gamma-function. It is included in ... - asked by Weather Report (9 votes), answered by WalkingRandomly (6 votes) ---------------------------- [Labeling a three-dimensional plot]\url{http://mathematica.stackexchange.com/questions/33236/labeling-a-t hree-dimensional-plot} As the title says, I want to add some text in a three-dimensional plot, thus labeling specific parts of it. Here is the corresponding Mathematica code V = 1/2*(x^2 + y^2 + z^2) + (x^2*y^2 + x^2*z^2 + ... - asked by Vaggelis_Z (7 votes), answered by Kuba (7 votes) ---------------------------- [Mathematica: computing a difficult integral]\url{http://mathematica.stackexchange.com/questions/33217/mathemat ica-computing-a-difficult-integral} I am trying to compute the following integral: Integrate[Exp[Sum[-((cw*\[Lambda] - b[i])^2/(2*\[Sigma]^2)), {i, 1, n}]], {cw, 0, 1}] And currently Mathematica outputs (Sqrt[\[Pi]/2]\[Sigma](Erf[(Sqrt[n](\[Lambda]- - asked by emaster70 (7 votes), answered by ybeltukov (8 votes) ---------------------------- [How to always display current section identifier (number, name) in notebook?]\url{http://mathematica.stackexchange.com/questions/33173/how-to- always-display-current-section-identifier-number-name-in-notebook} Because I find myself relocating frequently within a long notebook divided into sections, subsections, & subsubsections, I would like to display the identifying information for the section, etc. ... - asked by Brandon Marshall (7 votes), answered by ybeltukov (4 votes) ================================== Greatest hits from previous weeks: ================================== [Plotting Complex Quantity Functions]\url{http://mathematica.stackexchange.com/questions/3458/plotting -complex-quantity-functions} Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ... - asked by night owl (8 votes), answered by Artes (12 votes) ---------------------------- [How can I extract data points from a black and white image?]\url{http://mathematica.stackexchange.com/questions/3831/how-can-i-e xtract-data-points-from-a-black-and-white-image} Consider the following graph (source): Is there any way to extract the data points from this image in a semi-automatic way? I have seen, and tried the methods suggested in this question, but they ... - asked by Eli Lansey (29 votes), answered by Sjoerd C. de Vries (33 votes) ================================== Can you answer these? ================================== [How to embed graphic-element-specific metadata within a Graphics object?]\url{http://mathematica.stackexchange.com/questions/33207/how-to-em bed-graphic-element-specific-metadata-within-a-graphics-object} One of the most crucial requirements for rich, interactive scientific graphics is being able to "annotate" individual graphic elements (e.g. the data points of a scatterplot, the individual curves in ... - asked by kjo (1 vote) ---------------------------- [How to compute the Lovasz number for the given graph in Mathematica?]\url{http://mathematica.stackexchange.com/questions/33010/how- to-compute-the-lovasz-number-for-the-given-graph-in-mathematica} Here is a graph whose adjacency matrix is m = { {0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 0, 0}, {0, 0, 0, 1, 0, 0, 1, 1, 1, 0, 1, 0}, {0, 0, 0, 0, 1, 0, 1, 1, 1, 0, 0, 1}, {0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 1, ... - asked by Eden Harder (3 votes) ---------------------------- [NDSolve error when solving pde]\url{http://mathematica.stackexchange.com/questions/33166/ndsolve-error -when-solving-pde} I am trying to calculate speed of viscous fluid in a rotating hollow sphere. The sphere is rotating round z axis. The fluid is incompressible. I used Navier-Stockes equations. The only boundry ... - asked by Jure (1 vote) ================================== New blog post: ================================== [Plotting electronic orbitals using Mathematica]\url{http://mathematica.blogoverflow.com/2013/09/plotting-elect ronic-orbitals-using-mathematica/} by Jason B on Sep 27
================================== Top new questions this week: ================================== [Reconstruct text pages cut by shredder]\url{http://mathematica.stackexchange.com/questions/32612/reconstr uct-text-pages-cut-by-shredder} Q1: I have a page of printed text file, but it was cut by a paper shredder (from top to bottom). You can download all the paper fragment here. There are some examples of them. How can I reconstruct ... - asked by mm.Jang (24 votes), answered by Kuba (20 votes) ---------------------------- [Generate a Random Polygon]\url{http://mathematica.stackexchange.com/questions/32767/generate- a-random-polygon} Does some package exist with a function that takes a parameter $n$ and generates a random 2D $n$-sided simple polygon (convex or non-convex), possibly within a certain bounding box? It does not ... - asked by Herng Yi (13 votes), answered by Simon Woods (7 votes) ---------------------------- [How to examine the structure of Graphics objects]\url{http://mathematica.stackexchange.com/questions/32716/how-to-ex amine-the-structure-of-graphics-objects} One difficulty I'm encountering in studying the structure of Graphics objects is that I have not yet found a way to print or display such structure that is sufficiently general. The FullForm of ... - asked by kjo (12 votes), answered by Hector (11 votes) ---------------------------- [Size distribution of nanoparticles from a transmission electron microscopic image]\url{http://mathematica.stackexchange.com/questions/32830/size-distri bution-of-nanoparticles-from-a-transmission-electron-microscopic-imag} I have found a research article about Martian sand grain size determination from the image using Mathematica (Figure 2 in the linked article). They have not provided any detail of the methodology. It ... - asked by Uttam Pal (11 votes), answered by RM1618 (16 votes) ---------------------------- [Slideshow mode: how to cycle slides automatically?]\url{http://mathematica.stackexchange.com/questions/32768/sl ideshow-mode-how-to-cycle-slides-automatically} I'm doing a slideshow for an informative conference, so I need a slideshow running in background on some monitors. My question is: is there any way to make Mathematica to cycle slides automatically? ... - asked by markus (11 votes), answered by Hector (7 votes) ---------------------------- [What's the cleanest functional-programming style way to perform this list operation?]\url{http://mathematica.stackexchange.com/questions/32675/whats- the-cleanest-functional-programming-style-way-to-perform-this-list-opera t} I am looking for the correct method for accomplishing the unknown piece in the following code snippet: rolls = Tuples[Range[1, 4], {2}] {{1, 1}, {1, 2}, {1, 3}, {1, 4}, {2, 1}, {2, 2}, {2, 3}, {2, ... - asked by Techrocket9 (11 votes), answered by RunnyKine (6 votes) ---------------------------- [Solving Killing equations]\url{http://mathematica.stackexchange.com/questions/32843/solving -killing-equations} Is it possible to solve Killing equations in Mathematica for a general vector? I am looking for a way to create Killing equations and then find what the vectors are, but I have a problem with this. ... - asked by dingo_d (10 votes), answered by Daniel Lichtblau (11 votes) ================================== Greatest hits from previous weeks: ================================== [xkcd-style graphs]\url{http://mathematica.stackexchange.com/questions/11350/xkcd-style -graphs} I received an email to which I wanted to respond with a xkcd-style graph, but I couldn't manage it. Everything I drew looked perfect, and I don't have enough command over PlotLegends to have these ... - asked by Amatya (387 votes), answered by Simon Woods (256 votes) ---------------------------- [How to compile effectively?]\url{http://mathematica.stackexchange.com/questions/1803/how-t o-compile-effectively} What are the best practices of compiling functions? I understand that this is a vague question, but let me list some aspects that might trigger useful answers. Some of these have already been answered ... - asked by Istvan Zachar (65 votes), answered by Leonid Shifrin (60 votes) ================================== Can you answer these? ================================== [NDSolve and memory usage]\url{http://mathematica.stackexchange.com/questions/32640/ndsolve-and -memory-usage} After some googling, i've found similar problems around, but didn't find a 100% satisfactory answer, so let me ask here: I'd like to solve a 1+1 problem using the method of lines. In spherical ... - asked by Paolo (3 votes) ---------------------------- [How to simplify really complicated symbolic expression?]\url{http://mathematica.stackexchange.com/questions/32759/how-t o-simplify-really-complicated-symbolic-expression} I have an expression that contains Sinh[x], Cosh[x] and Sin[g], and I want to simplify it into an easier form, based on the physics situation (I am doing some general relativity calculation), I know ... - asked by Jason (1 vote) ---------------------------- [When should I begin a new line for more readable code]\url{http://mathematica.stackexchange.com/questions/32870/when-should- i-begin-a-new-line-for-more-readable-code} After a quick coding, I often try a lot of line feeds patterns on it. And no matter how much I do, there's seems to be no end in sight. Front end automatically indents the code, but I cannot fully ... - asked by asoldat (4 votes)
================================== Top new questions this week: ================================== [Is it possible to use RandomChoice to choose without other choices being evaluated?]\url{http://mathematica.stackexchange.com/questions/32175/is-it- possible-to-use-randomchoice-to-choose-without-other-choices-being-evalu at} I'm trying to do this: i1 = 1; i2 = 1; RandomChoice[{ (i1 = i1 + 1), (i1 = i1 - 1), (i2 = i1 + 1), (i2 = i2 - 1)}] In order to chose randomly which variable is going to be incremented or ... - asked by Gustavo Bandeira (14 votes), answered by ybeltukov (13 votes) ---------------------------- [Color Histogram3D by Bin Location]\url{http://mathematica.stackexchange.com/questions/32460/color-hi stogram3d-by-bin-location} I am using a Histogram3D plot to view the correlation of the R & G of an RGB image. Naturally, I want the bins to have a color corresponding to their $x$, $y$ (R,G) position on the chart. ... - asked by Perfect Tommy (11 votes), answered by Kuba (10 votes) ---------------------------- [Method -> {"AxesInFront" -> False} for Graphics3D]\url{http://mathematica.stackexchange.com/questions/32168/method -axesinfront-false-for-graphics3d} I'm aware of two ways to manage positioning of Axes for Graphics3D: AxesOrigin and AxesEdge. They seem to be quite different in terms of what is actually happening: GraphicsRow[{ ... - asked by Kuba (11 votes), answered by Brett Champion (2 votes) ---------------------------- [Why does Mathematica return a Fourier transform for a function for which it is not defined?]\url{http://mathematica.stackexchange.com/questions/32387/why-does -mathematica-return-a-fourier-transform-for-a-function-for-which-it-is-n > } The following function $$g(x) = (1 + x^{1/a} )^a $$ should NOT have a Fourier transform, as far as I am aware, for any real values of $a$ since $g(x)$ is not nice in the sense of decays quickly ... - asked by Luap Nalehw (10 votes), answered by ybeltukov (11 votes) ---------------------------- [Find eigen energies of time-independent Schrodinger equation]\url{http://mathematica.stackexchange.com/questions/32293/find-eig en-energies-of-time-independent-schrodinger-equation} I'm trying to get the eigenvalues of a one dimensional time-independent Schrodinger equation, $-\frac{h^2}{2m_0}\frac{d^2\psi}{dx^2}+U(x)~\psi=Ei~\psi$ where U(x) is some potential and Ei is the ... - asked by xslittlegrass (10 votes), answered by Jens (13 votes) ---------------------------- [Is there a triangle like this?]\url{http://mathematica.stackexchange.com/questions/32338/is-there-a- triangle-like-this} I want to find the numbers $a$, $b$, $c$, $d$ of the function $y = \dfrac{a x + b}{c x + d}$ so that the triangle $ABC$ with three points $A$, $B$, $C$ have integer coordinates and lies on the graph ... - asked by minthao_2011 (8 votes), answered by belisarius (15 votes) ---------------------------- [Unexpected behaviour of Solve applied to two equations in two variables]\url{http://mathematica.stackexchange.com/questions/32246/unexpec ted-behaviour-of-solve-applied-to-two-equations-in-two-variables} I have a simple Mathematica expression Solve[{a(a-1)Sqrt[1+a^2+b^2] == b(a^3-1), b(b-1)Sqrt[1+a^2+b^2] == a(b^3-1)}] which returns (on version 8.0, and also version 9.0) {{b -> -(a/(1 + a))}, ... - asked by Ashley Montanaro (8 votes), answered by gpap (2 votes) ================================== Greatest hits from previous weeks: ================================== [Finding the centroid of the area between two curves]\url{http://mathematica.stackexchange.com/questions/17170/finding-th e-centroid-of-the-area-between-two-curves} When I have an area bounded by curves, is there a built-in way to find the center of the area? Or do I have to plot it first and then use ComponentMeasurements on it? For example: the area under $y= ... - asked by a3f (9 votes), answered by george2079 (3 votes) ---------------------------- [How can I improve Mathematica's resolution on a macbook retina display?]\url{http://mathematica.stackexchange.com/questions/18419/how-can- i-improve-mathematicas-resolution-on-a-macbook-retina-display} Mathematica looks a bit fuzzy on the retina screen, how can I increase the resolution? Here another screenshot showing a direct comparison between the browser and Mathematica - asked by Tom Wellington (23 votes), answered by programming_historian (10 votes) ================================== Can you answer these? ================================== [Setting PropertyValue for VertexWeight is not persistent]\url{http://mathematica.stackexchange.com/questions/32320/settin g-propertyvalue-for-vertexweight-is-not-persistent} g = CompleteGraph[8, VertexSize -> Medium]; PropertyValue[{g, VertexList[g][[1]]}, VertexWeight] = 10; PropertyValue[g, VertexWeight] {10, 1, 1, 1, 1, 1, 1, 1} PropertyValue[{g, ... - asked by Ilya Sorokin (2 votes) ---------------------------- [Orthogonal basis of a hermitian matrix]\url{http://mathematica.stackexchange.com/questions/32350/orthogonal -basis-of-a-hermitian-matrix} Is there a way to extract an orthogonal basis for a hermitian matrix in Mathematica? A simple diagnolization returns a non orthogonal basis and later using a Grahm-Schmidt process which isn't aware ... - asked by user9522 (1 vote) ---------------------------- [Convert ImageSize to FieldSize]\url{http://mathematica.stackexchange.com/questions/32459/convert -imagesize-to-fieldsize} How might I construct a function called EmToPX[p] such that the following 2 InputFields would be the same width. If not please explain why doing such isn't possible. InputField["a", ImageSize -> ... - asked by Liam William (1 vote)
================================== Top new questions this week: ================================== [Chart illustrating options that affect Graphics/Graphics3D objects]\url{http://mathematica.stackexchange.com/questions/31745/chart-ill ustrating-options-that-affect-graphics-graphics3d-objects} In Mathematica there is a seemingly never-ending list of parameters that affect the appearance of Graphics and Graphics3D objects: ImageSize, ImageSizeRaw, ImagePadding, ImageMargins, PlotRange, ... - asked by kjo (19 votes), answered by Vitaliy Kaurov (18 votes) ---------------------------- [The dangers of SaveDefinitions --- should this really happen?]\url{http://mathematica.stackexchange.com/questions/31998/the-dange rs-of-savedefinitions-should-this-really-happen} I have been bitten hard by SaveDefinitions -> True. I'll describe in detail what happened below. My questions are: Is this a bug? What is the most convenient workaround? Consider a definition ... - asked by Szabolcs (17 votes), answered by Rojo (12 votes) ---------------------------- [How to get Cases to wrap results in an arbitrary head?]\url{http://mathematica.stackexchange.com/questions/31754/how-to-get- cases-to-wrap-results-in-an-arbitrary-head} A number of functions provide for results to be wrapped in an arbitrary head. This is very important in cases where the results should not be evaluated. Take Level as an example: expr = Hold[{2/2, ... - asked by Mr.Wizard (17 votes), answered by Mr.Wizard (15 votes) ---------------------------- [Do Mathematica notebooks include personal metadata?]\url{http://mathematica.stackexchange.com/questions/31928/do-math ematica-notebooks-include-personal-metadata} I am about to send a Mathematica notebook to someone and I would like to make sure it does not contain any information that could personally identify me. I would also like to produce pdf files from ... - asked by episanty (13 votes) ---------------------------- [How to determine numeric equivalent of Tiny, Small, etc. image sizes for Graphics?]\url{http://mathematica.stackexchange.com/questions/31726/how-to- determine-numeric-equivalent-of-tiny-small-etc-image-sizes-for-graphic} Is there a way to find the numeric equivalents of Tiny, Small, Medium, and Large for for ImageSize? In other words, what are the integers t, s, m, and l such that, for Graphics objects, the ... - asked by kjo (13 votes), answered by Szabolcs (12 votes) ---------------------------- [Can ReplacePart be sped up?]\url{http://mathematica.stackexchange.com/questions/31648/can-replacepa rt-be-sped-up} Test case: data = RandomReal[1, {1000, 1000}]; pos = RandomInteger[{1, 1000}, {5*10^5, 2}]; r1 = ReplacePart[data, pos -> 0]; // AbsoluteTiming (data[[##]] = 0) & @@@ pos; // AbsoluteTiming ... - asked by explorer (12 votes), answered by jVincent (4 votes) ---------------------------- [How to identify chemical substance from tattoo?]\url{http://mathematica.stackexchange.com/questions/31657/how-to-id entify-chemical-substance-from-tattoo} A friend of mine made a tattoo on his chest of some chemical substance formula. He challenged us to identify which substance is that. I thought that perhaps a combination of: Mathematica image ... - asked by Zet (12 votes), answered by Sjoerd C. de Vries (18 votes) ================================== Greatest hits from previous weeks: ================================== [How to manipulate 2D plots?]\url{http://mathematica.stackexchange.com/questions/7142/how-to-mani pulate-2d-plots} When it comes to visual analysis, large datasets or data with intricate internal details often makes plotting in 2D useless, as the outcome is either just a fraction of the full dataset, or no details ... - asked by Istvan Zachar (54 votes), answered by Istvan Zachar (53 votes) ---------------------------- [QR Code in shopping cart handle]\url{http://mathematica.stackexchange.com/questions/26268/qr-code-in -shopping-cart-handle} This week, the market people from my work wanted to put QR codes in shopping cart handles, but when they tested it, the QR code did not work. I noted that the cylindrical curvature (even small) ... - asked by Murta (122 votes), answered by halirutan (121 votes) ================================== Can you answer these? ================================== [How can I create jpeg images of a given file size?]\url{http://mathematica.stackexchange.com/questions/31814/how-can-i-c reate-jpeg-images-of-a-given-file-size} Cross-posted at Wolfram Community I would like to have a function makeJPG[megabytes_] that generates random jpg images of given file sizes with itf filesize (in megabytes) watermarked on the image ... - asked by M.R. (3 votes) ---------------------------- [Understanding the discrepancy between txt file import and export times, and possibly speeding up Import]\url{http://mathematica.stackexchange.com/questions/31817/understand ing-the-discrepancy-between-txt-file-import-and-export-times-and-poss} I attempted to import a very short .txt file string using the Import command: Import["C:\\TestFile.txt"] // AbsoluteTiming Out: {0.020001, "Test"} Why does this take 20 milliseconds? Export is ... - asked by Sparse Pine (1 vote) ---------------------------- [Setting OperatorSubstitution to false causes Plot's labels of sufficiently small size not to appear in the specified typeface. Is this a bug?]\url{http://mathematica.stackexchange.com/questions/31784/setting-oper atorsubstitution-to-false-causes-plots-labels-of-sufficiently-small} If I set OperatorSubstitution to False, the labels of Plot will not use the typeface specified by FontFamily unless FontSize is more than certain number. In this test scenario, that certain number is ... - asked by Taiki (2 votes)
================================== Top new questions this week: ================================== [How to create a wind rose with Mathematica?]\url{http://mathematica.stackexchange.com/questions/31257/how- to-create-a-wind-rose-with-mathematica} I am trying to plot wind rose in Mathematica, but have no idea how to do this. Any suggestions ? - asked by bushiwo (22 votes), answered by David Carraher (16 votes) ---------------------------- [How to include Mathematica animation in a PowerPoint presentation?]\url{http://mathematica.stackexchange.com/questions/31511/how -to-include-mathematica-animation-in-a-powerpoint-presentation} I want to include a Mathematica animation in PowerPoint presentation. My code is: SetDirectory[NotebookDirectory[]]; data = ReadList[ "C:\\Users\\luka\\Desktop\\GRAFI- DIPLOMA\\9_gibanje \ ... - asked by Luka (15 votes), answered by Vitaliy Kaurov (18 votes) ---------------------------- [How do I calculate the area of a polygon given its coordinates?]\url{http://mathematica.stackexchange.com/questions/31241/how- do-i-calculate-the-area-of-a-polygon-given-its-coordinates} I have a polygon: Polygon[{{0, 200 }, {200, 100}, {500, 300}, {100, 700}}] How can I figure out its area? The docs page does not have any example. So far I've reached this point with no success: ... - asked by caligula (15 votes), answered by Kuba (14 votes) ---------------------------- [Pick elements of largest absolute value]\url{http://mathematica.stackexchange.com/questions/31385/pick-elemen ts-of-largest-absolute-value} For example, given list = {{1, -3, -5}, {2, 1, 6}, {0, 2, 4}, {-9, 2, 6}} should return: {-5, 6, 4, -9} - asked by explorer (15 votes), answered by Simon Woods (19 votes) ---------------------------- [How to partition a list to make each subset's size equal and mean as close as possible]\url{http://mathematica.stackexchange.com/questions/31469/how-to-p artition-a-list-to-make-each-subsets-size-equal-and-mean-as-close-as-po> ) Suppose we have 3 lists each with 18 numbers like this: list1 = {7.49, 7.56, 7.98, 8.09, 8.16, 8.21, 8.73, 8.64, 8.68, 8.46, 8.57, 8.29, 9.38, 9.43, 8.95, 9.04, 8.9, 9.07}; list2 = {21.08, ... - asked by incognito007 (13 votes), answered by Vitaliy Kaurov (4 votes) ---------------------------- [How can one write a robust ListableQ function?]\url{http://mathematica.stackexchange.com/questions/31498/how-can -one-write-a-robust-listableq-function} I would like to have a test that determines if a particular function is Listable. In the case of Symbols this is merely a matter of checking Attributes. Function definitions with the Listable ... - asked by Mr.Wizard (12 votes), answered by Mr.Wizard (5 votes) ---------------------------- [How can I efficiently "remap" an image?]\url{http://mathematica.stackexchange.com/questions/31274/how-can-i- efficiently-remap-an-image} Many image processing libraries like OpenCV, Intel Performance Primitives or Octave have a useful function called "remap", that takes an image, an array with X coordinates and an array with Y ... - asked by nikie (11 votes), answered by ssch (7 votes) ================================== Greatest hits from previous weeks: ================================== [Voronoi diagrams for generators other than points]\url{http://mathematica.stackexchange.com/questions/20696/voronoi-di agrams-for-generators-other-than-points} Any suggestions how to determine Voronoi diagram for sites other than points, as e.g. in the picture below? Input is a raster image. - asked by DeeDee (22 votes), answered by whuber (26 votes) ---------------------------- [How to compile effectively?]\url{http://mathematica.stackexchange.com/questions/1803/how-t o-compile-effectively} What are the best practices of compiling functions? I understand that this is a vague question, but let me list some aspects that might trigger useful answers. Some of these have already been answered ... - asked by Istvan Zachar (65 votes), answered by Leonid Shifrin (59 votes) ================================== Can you answer these? ================================== [Generating an obstacle-avoiding closed-curve with a fixed perimeter and a target area]\url{http://mathematica.stackexchange.com/questions/31365/generating-a n-obstacle-avoiding-closed-curve-with-a-fixed-perimeter-and-a-target} I was wondering if there was a neat way to solve the following problem in Mathematica v9 - Provided a binarized image (where we call black pixels "obstacles" or vice versa, whichever is most ... - asked by TilePath (3 votes) ---------------------------- [What was added to the LibraryLink API in version 9?]\url{http://mathematica.stackexchange.com/questions/31433/what-was-added -to-the-librarylink-api-in-version-9} Looking at the LibraryLink examples, there are several new functions and objects, as well as example programs, that appeared in version 9. Are these documented? If yes, where? If would be nice to ... - asked by Szabolcs (9 votes) ---------------------------- [Stochastic differential equations in the weak sense]\url{http://mathematica.stackexchange.com/questions/31443/stochastic- differential-equations-in-the-weak-sense} There are some good discussions in http://mathematica.stackexchange.com regarding the numerical solution of SDEs of the form $dX(t)=a(t,X)dt+b(t,X)dW_t$, wherein $X(0)=X_{0},$ $W_t$ is the Wiener ... - asked by Fazlollah Soleymani (1 vote)
================================== Top new questions this week: ================================== [Cropping a Voronoi diagram]\url{http://mathematica.stackexchange.com/questions/31187/cropping- a-voronoi-diagram} Someone know how can I get the correct crop of this Voronoi image using RegionFunction? As you can see, there is a lot of undesired white regions inside the left polygon. Some clue on how to correct ... - asked by Murta (12 votes), answered by Kuba (7 votes) ---------------------------- [Automatically close Mathematica]\url{http://mathematica.stackexchange.com/questions/30974/autom atically-close-mathematica} It seems there are a lot of related topics but I haven't found an answer. I want to automatically quit Mathematica after some procedures are done but dialog window appears: 1 + 1; ... - asked by Kuba (11 votes), answered by John Fultz (11 votes) ---------------------------- [Encrypt the password used for SendMail]\url{http://mathematica.stackexchange.com/questions/30836/encrypt- the-password-used-for-sendmail} I want Mathematica to send me an email when the computation is finished. To that end, I have a cell with SendMail[...] which I place behind my computation in the evaluation queue. The problem I have ... - asked by simsurace (11 votes), answered by Murta (10 votes) ---------------------------- [Detecting and correcting gradational brightness variations in a grayscale image]\url{http://mathematica.stackexchange.com/questions/30823/detecting-a nd-correcting-gradational-brightness-variations-in-a-grayscale-image} I am trying to quantify the proportions of various components in a greyscale image (backscattered electron image of a polished rock sample). Here is the original image: bse = ... - asked by geordie (10 votes), answered by Simon Woods (5 votes) ---------------------------- [Select and Blank]\url{http://mathematica.stackexchange.com/questions/30970/select-and- blank} I try to filter sublists of a list which match a pattern. test = {{"String1", "a"}, {"String2", "b"}, {"String3", "a"}, {"String4", "a"}}; The result should be: result = {{"String1", "a"}, ... - asked by RMMA (8 votes), answered by halirutan (13 votes) ---------------------------- [Cannot find the maximum value of a function]\url{http://mathematica.stackexchange.com/questions/31032/cannot-f ind-the-maximum-value-of-a-function} Consider the following function: $a Sin(x)+b Cos(x)$ I tried to obtain the maximum value of this function using MaxValue[]: MaxValue[a Sin[x] + b Cos[x], x, Reals] I expect Mathematica to return ... - asked by M6299 (7 votes), answered by george2079 (3 votes) ---------------------------- [How can I draw a grid behind graphics without using Plot?]\url{http://mathematica.stackexchange.com/questions/31114/how-can-i-d raw-a-grid-behind-graphics-without-using-plot} I want to a show simple vector summation but I don't know how to draw a grid behind the vectors. I am pretty sure I can do it with Mathematica but how? It should look like this: - asked by Serkan (7 votes), answered by Mr.Wizard (15 votes) ================================== Greatest hits from previous weeks: ================================== [Using the Mathematica front-end efficiently for editing notebooks]\url{http://mathematica.stackexchange.com/questions/8310/using-th e-mathematica-front-end-efficiently-for-editing-notebooks} Background: I have used Vim for 15+ years. There is a certain "one"-ness with the editor one achieves. Emacs users also experience this. Notepad users do not. My current interaction with the ... - asked by user1602 (40 votes), answered by rm -rf (38 votes) ---------------------------- [How can this image (optical illusion) be created with Mathematica?]\url{http://mathematica.stackexchange.com/questions/24148/how- can-this-image-optical-illusion-be-created-with-mathematica} I came across this image the other day: and liked the sensation of it pulsing. I was wondering if anyone would know how to create something similar with Mathematica (without the Pink Floyd Dark ... - asked by Mike Honeychurch (32 votes), answered by halirutan (48 votes) ================================== Can you answer these? ================================== [Assign variables from list inside With or Module]\url{http://mathematica.stackexchange.com/questions/30847/assign-var iables-from-list-inside-with-or-module} I have found that it is possible to assign variables from lists, as follows. In[1]:= r = {1, 2, 3}; In[2]:= {a, b, c} = r; In[3]:= b Out[3]= 2 However, if I try to do this within a With or Module ... - asked by Gyppo (2 votes) ---------------------------- [Is there a way to speed up Simplify and/or PolynomialReduce Modulus-> 2?]\url{http://mathematica.stackexchange.com/questions/31029/is-there-a-way -to-speed-up-simplify-and-or-polynomialreduce-modulus-2} I'm trying to simplify a series of equations with at most 64 input terms. As the number of terms involved in the equations increase, the runtime seems to grow exponentially. Does anyone know of ways ... - asked by botnet (1 vote) ---------------------------- [FrontEndTokens, MathLink, and Serializer.exe]\url{http://mathematica.stackexchange.com/questions/31118/fr ontendtokens-mathlink-and-serializer-exe} I have been using some basic MathLink programming in my work and wanted to create some more sophisticated MathLink programs. I came across the book "MathLink: Network Programming with Mathematica", ... - asked by user2694879 (2 votes)
================================== Top new questions this week: ================================== [What bug fixes can be implemented in init.m?]\url{http://mathematica.stackexchange.com/questions/30599/what-bug- fixes-can-be-implemented-in-init-m} In comments on this question, Mr. Wizard suggested a community wiki to share the bug fixes/workarounds (or possibly other tricks) people load in their init.m. I think this could provide a nice ... - asked by jkrich (16 votes), answered by Mr.Wizard (8 votes) ---------------------------- [when is f@g not the same as f[g]?]\url{http://mathematica.stackexchange.com/questions/30425/when-is-fg- not-the-same-as-fg} I have always thought that f@g will give the same result as f[g] in all cases, and it is just a matter of style which one to use and that g will always evaluates first, and then f will evaluate using ... - asked by Nasser (16 votes), answered by Mr.Wizard (22 votes) ---------------------------- [Blend code for "Sunset Colors"]\url{http://mathematica.stackexchange.com/questions/30508/blend-cod e-for-sunset-colors} Hi I want to get a blend similar to "SunsetColors". To make those slight modifications, I would like to know the precise blend of that ColorScheme. My try: Graphics[Table[{Blend[{Black, ... - asked by Francisco (14 votes), answered by Simon Woods (13 votes) ---------------------------- [Looking for a way to insert multiple elements into multiple positions simultaneously in a list]\url{http://mathematica.stackexchange.com/questions/30647/looking-for- a-way-to-insert-multiple-elements-into-multiple-positions-simultaneo} I would like to take the following data: insertvalues = {r, x}; insertpositions = {{1}, {5}}; origlist = {a, b, c, d, e, f, g}; and generate output that looks like this: {r,a,b,c,d,x,e,f,g} ... - asked by Todd Allen (13 votes), answered by Mr.Wizard (14 votes) ---------------------------- [How can I manipulate TemporalData?]\url{http://mathematica.stackexchange.com/questions/30712/how -can-i-manipulate-temporaldata} Version 9 introduced TemporalData but, truth be told, the documentation doesn't suggest that one can do much with it. Many of us have probably assumed we'd be better off sticking with the date-value ... - asked by Verbeia (13 votes), answered by Verbeia (15 votes) ---------------------------- [Measure perimeter of black edge in Mathematica]\url{http://mathematica.stackexchange.com/questions/30461/measu re-perimeter-of-black-edge-in-mathematica} I have a pattern like the one below. How could I measure the total length of the perimeter of the black/white edge? This would give me a measure of spatial frequency. Any tips would be great! Thanks! ... - asked by Levi (13 votes), answered by belisarius (11 votes) ---------------------------- [Filtering elements from a list that appear only once]\url{http://mathematica.stackexchange.com/questions/30610/filtering-el ements-from-a-list-that-appear-only-once} I want to be able to select elements from a list that only appear once. I originally had this: Select[Table[Count[list, i], {i, list}], # == 1] But the issue is that my list has about 60,000 ... - asked by Mark (12 votes), answered by belisarius (17 votes) ================================== Greatest hits from previous weeks: ================================== [How to create hedcut style images?]\url{http://mathematica.stackexchange.com/questions/8716/how-to-cre ate-hedcut-style-images} Yesterday the hedcut style was brought up in chat. How can we create a hedcut-like style automatically in Mathematica, using a photograph as a starting point? I am looking to create a similar ... - asked by Szabolcs (43 votes), answered by Simon Woods (32 votes) ---------------------------- [Plotting Complex Quantity Functions]\url{http://mathematica.stackexchange.com/questions/3458/plotting -complex-quantity-functions} Trying to plot with complex quantities seems not to work properly in what I want to accomplish. I would like to know if there is a general rule/way of plotting when you have complex counterparts in ... - asked by night owl (8 votes), answered by Artes (12 votes) ================================== Can you answer these? ================================== [NDSolve: ProcessEquations and Reinitialize with Piecewise functions]\url{http://mathematica.stackexchange.com/questions/30426/ndsolve -processequations-and-reinitialize-with-piecewise-functions} I am having trouble with using NDSolve`Reinitialize when the system consists of a pieceise function. If we define the ODE system simplesys = {r'[t] == Piecewise[{{1, 0 <= t <= 10}, {0, 10 ... - asked by jaclea (3 votes) ---------------------------- [Does one need to be careful about loading multiple (many) contexts or packages in the same session?]\url{http://mathematica.stackexchange.com/questions/30758/does-one -need-to-be-careful-about-loading-multiple-many-contexts-or-packages-i} I have a number of large pieces of precomputed data which I am considering putting into individual packages in order to load them (via DeclarePackage) and unload them (via Leonid Shifrin's ... - asked by Tobias Hagge (4 votes) ---------------------------- [Mathematica and strong AI]\url{http://mathematica.stackexchange.com/questions/30585/mathematica-an d-strong-ai} David Deutsch (physicist / quantum computing theorist) wrote an article for Aeon Magazine last year: On Artificial Intelligence that got me thinking. The article assesses and critiques the ... - asked by Jagra (7 votes)
================================== Top new questions this week: ================================== [Detecting patterns of black and white stones on a 2D board]\url{http://mathematica.stackexchange.com/questions/46631/detecting-p atterns-of-black-and-white-stones-on-a-2d-board} I'm writing a program to play a game of Pente, and I'm struggling with the following question: What's the best way to detect patterns on a two-dimensional board? For example, in Pente a pair of ... - asked by Victor K. (20 votes), answered by Mr.Wizard (9 votes) ---------------------------- [Is there a better way to add elements to a Graphics expression repeatedly?]\url{http://mathematica.stackexchange.com/questions/46746/is-th ere-a-better-way-to-add-elements-to-a-graphics-expression-repeatedly} Consider simple example where a set of points is generated and some are displayed. k = 10^5; p = RandomReal[{-1, 1}, {k, 2}]; n = 2 Graphics[Dynamic@Point@p[[;; n]], Frame -> True, PlotRange -> ... - asked by Kuba (13 votes), answered by Rom38 (5 votes) ---------------------------- [Full documentation for AppearanceElements]\url{http://mathematica.stackexchange.com/questions/4679 2/full-documentation-for-appearanceelements} As explained in this solution, ListAnimate[Table[Plot[Sin[n x], {x, 0, 2}], {n, 3}]]//InputForm will allow me to view the types of appearance element for the ListAnimate controller. But the same ... - asked by fairflow (8 votes), answered by Nasser (8 votes) ---------------------------- [StringReplace, ReplaceAll and Rule interact in a bizarre way]\url{http://mathematica.stackexchange.com/questions/46611/stringreplace -replaceall-and-rule-interact-in-a-bizarre-way} I have the following pair of things: ClearAll[foo, labeledFoo]; labeledFoo = {"FooBarBazQuux", foo}; This works like you'd expect: labeledFoo /. hdr_String :> StringReplace[hdr, ... - asked by Pillsy (8 votes), answered by Leonid Shifrin (11 votes) ---------------------------- [Is it possible to create iOS apps with Mathematica?]\url{http://mathematica.stackexchange.com/questions/46888/is-i t-possible-to-create-ios-apps-with-mathematica} I am fairly new to Mathematica and don't have much experience with other programming languages, but I can already see that Mathematica and the Wolfram language are far easier to use than most others. ... - asked by Aron (7 votes), answered by Vitaliy Kaurov (9 votes) ---------------------------- [Creating a Mathieu stability diagram]\url{http://mathematica.stackexchange.com/questions/46750/creating- a-mathieu-stability-diagram} I am attempting to re-create a Mathieu stability diagram like the one shown here: I expected that I could use MathieuC to generate this graph by assuming that instability occurs when the function ... - asked by bobthechemist (7 votes), answered by Oleksandr R. (10 votes) ---------------------------- [How to request financial data from Yahoo's YQL?]\url{http://mathematica.stackexchange.com/questions/46760/how-to-reque st-financial-data-from-yahoos-yql} How can I download historical data from Yahoo ? Although Mathematica's FinancialData function uses Yahoo it could be useful to have more control on how to retrieve data from Yahoo's YQL. - asked by Faysal Aberkane (7 votes), answered by Faysal Aberkane (12 votes) ================================== Greatest hits from previous weeks: ================================== [Get a "step by step" evaluation in Mathematica]\url{http://mathematica.stackexchange.com/questions/148/get-a-s tep-by-step-evaluation-in-mathematica} Is it possible in Mathematica to get a step-by-step evaluation of some functions; that's to say, outputting not only the result but all the stages that have led to it? Example : Let's say I want to ... - asked by Skydreamer (50 votes), answered by J.M. (44 votes) ---------------------------- [How to create word clouds?]\url{http://mathematica.stackexchange.com/questions/2334/how-to-cre ate-word-clouds} Word clouds are rather useless fancy and visually appealing plots, where words are plotted with different sizes according to their frequency in a corpus. Many applications exist out there (Wordle, ... - asked by Istvan Zachar (91 votes), answered by Heike (78 votes) ================================== Can you answer these? ================================== [What is " (Dialog) Input [ ] := " after evaluating a cell?]\url{http://mathematica.stackexchange.com/questions/46669/what-is-dia log-input-after-evaluating-a-cell} I have done a time-consuming run and calculation. After many hours ( about 7 hours!), the black color which shows that the cell is evaluating, turn into gray and a strange text appears like this : ... - asked by Shellp (2 votes) ---------------------------- [make mathematica recognize CCompiler and NVCC on remote Windows machine]\url{http://mathematica.stackexchange.com/questions/46971/make-math ematica-recognize-ccompiler-and-nvcc-on-remote-windows-machine} I have setup a mathematica remote kernel on a Windows 7 64 bit machine, which has MS Visual Studio 2010 installed. When I start mathematica on the windows machine mathematica recognizes the MS ... - asked by Wizard (1 vote) ---------------------------- [Function with a sharp resonance which Mathematica fails to integrate. Why?]\url{http://mathematica.stackexchange.com/questions/46737/function-wit h-a-sharp-resonance-which-mathematica-fails-to-integrate-why} I'm a new user of Mathematica and I'm trying to use it to calculate the collisional cross-section as a function of energy for a given potential and decay rate. I know that the resulting function ... - asked by Woody (3 votes)
================================== Top new questions this week: ================================== [Undocumented form for Extract]\url{http://mathematica.stackexchange.com/questions/46261/undocumen ted-form-for-extract} Prompted by a comments conversation here, here's an interesting (and often performance enhancing) use of Extract: target = Join[Range[100], {{1, 2, 3, Range[20]}}]; Rest@Extract[target, {{{}}, {2 ;; ... - asked by rasher (17 votes), answered by Jacob Akkerboom (7 votes) ---------------------------- [Bizarre behavior of With, Compile and Break]\url{http://mathematica.stackexchange.com/questions/46315/bizarre-beh avior-of-with-compile-and-break} I'm guessing this is almost certainly a bug in Compile (because they're fairly common), but it's pretty weird and I spent about an hour tracking down the issue and finding a test case. Consider this ... - asked by Pillsy (10 votes), answered by Leonid Shifrin (10 votes) ---------------------------- [Finding "Maxima" and "Minima" on a B-Spline]\url{http://mathematica.stackexchange.com/questions/46517/finding- maxima-and-minima-on-a-b-spline} I need to find the "Maxima" and "Minima" on a B-Spline or more correct the points where the 2nd components of the derivate equal zero. For example: g = BSplineFunction[{{1, 2}, {2, 4}, {3, -1}, ... - asked by cxkoda (8 votes), answered by Silvia (12 votes) ---------------------------- [Select cases from a list]\url{http://mathematica.stackexchange.com/questions/46472/select-cases -from-a-list} I have a list in the form : {1,1,1,0,-1,-1,1,1,1,0,0,0,0,-1,-1} No I'm trying to select only those sequences which start with 1 have a zero (or many zeros) between and are followed by -1. For ... - asked by holistic (8 votes), answered by halirutan (11 votes) ---------------------------- [Filling a curve between a line and the x-axis]\url{http://mathematica.stackexchange.com/questions/46332/filling-a- curve-between-a-line-and-the-x-axis} I'm trying to plot the function $f(x)=\dfrac{1}{x^2}$, filling the square area from (0,0) to (1,1) with purple and filling the area under the curve from 1 to 4 with red. However, Mathematica is not ... - asked by Eudokia (8 votes), answered by Kuba (7 votes) ---------------------------- [Explain the difference between ViewPoint and ViewVector?]\url{http://mathematica.stackexchange.com/questions/46266/expla in-the-difference-between-viewpoint-and-viewvector} I've read the documentation, but am still very unclear as to what the difference is between ViewVector and ViewPoint for Graphics3D. Could someone explain it concisely and clearly enough so that an ... - asked by Aron (7 votes), answered by Pickett (3 votes) ---------------------------- [Measuring curve length on a binarized image]\url{http://mathematica.stackexchange.com/questions/46342/measuring-c urve-length-on-a-binarized-image} With the help of almighty Mathematica 9, I got from this To this: with this code: MorphologicalBinarize[ Import["http://i.stack.imgur.com/79l19.jpg"]~ ColorConvert~"Grayscale"]; ... - asked by iccthedral (7 votes), answered by halirutan (6 votes) ================================== Greatest hits from previous weeks: ================================== [How to generate a random snowflake]\url{http://mathematica.stackexchange.com/questions/39361/how-to- generate-a-random-snowflake} 'Tis the season... And it's about time I posed my first question on Mathematica Stack Exchange. So, here's an holiday quest for you Graphics (and P-Chem?) gurus. What is your best code for generating ... - asked by Peltio (86 votes), answered by Silvia (117 votes) ---------------------------- [What is the best Mathematica tutorial for young people?]\url{http://mathematica.stackexchange.com/questions/733/what-is-the -best-mathematica-tutorial-for-young-people} As Conrad Wolfram said at the TED conference, in the future kids should focus more on new technology. Computers compute better than humans, so we should focus more on thinking and getting the ... - asked by noisy (32 votes), answered by Vitaliy Kaurov (17 votes) ================================== Can you answer these? ================================== [How to get mathematica to simplify a result]\url{http://mathematica.stackexchange.com/questions/46254/how-to-get -mathematica-to-simplify-a-result} I have the following output $\text{Li}_2\left(3-2 \sqrt{2}\right)-4 \text{Li}_2\left(-1+\sqrt{2}\right)$. This turns out to be equivalent to $\displaystyle\log^2(1+\sqrt{2})-\frac{\pi^2}{4}$. How ... - asked by Oliver (3 votes) ---------------------------- [Why does Network`GraphPlot`wrapper appear in my GraphPlot?]\url{http://mathematica.stackexchange.com/questions/46377/why-do es-networkgraphplotwrapper-appear-in-my-graphplot} I'm making a GraphPlot of data similar to this: gpd = ... - asked by ArgentoSapiens (1 vote) ---------------------------- [Simplifying trig expressions containing Sqrt or Abs]\url{http://mathematica.stackexchange.com/questions/46560/simplifying-t rig-expressions-containing-sqrt-or-abs} The following Maple code can simplify abs(sin(x)) into -sin(x) given the condition -3Pi/4 < x < -Pi/2 simplify(abs(sin(x))) assuming -3*Pi < x, x < -5*Pi/2; I tried what I thought would ... - asked by mathe (6 votes)
================================== Top new questions this week: ================================== [Sketch-type graphics with transparency and dashed hidden lines?]\url{http://mathematica.stackexchange.com/questions/45410/sketch-typ e-graphics-with-transparency-and-dashed-hidden-lines} I'd like to create transparent graphs like the following from P1095, Calculus 6th Ed, by James Stewart. Can Mathematica accomplish this? By "transparent," I mean the ability to see the interior, ... - asked by LePressentiment (18 votes), answered by Silvia (35 votes) ---------------------------- [Animating moving surface of torus]\url{http://mathematica.stackexchange.com/questions/45417/animating-m oving-surface-of-torus} I would like to try to recreate something similar to Paolo eri's torus animation: I have isolated the moving surface torus section form this Wolfram Demonstration by Kevin Sonnanburg: t = s; s = ... - asked by martin (11 votes), answered by Kuba (15 votes) ---------------------------- [Fit two intersecting straight lines in Mathematica]\url{http://mathematica.stackexchange.com/questions/45401/fit-t wo-intersecting-straight-lines-in-mathematica} I am trying to do a Kurie analysis of the double beta decay of Strontium-90. Here we have two straight sections, and I need to obtain a value for the intersection along with an error for it. I ... - asked by ephimetheus (11 votes), answered by Vitaliy Kaurov (13 votes) ---------------------------- [Plotting Fourier spectrum versus frequency of a signal]\url{http://mathematica.stackexchange.com/questions/45502/plotting-f ourier-spectrum-versus-frequency-of-a-signal} I have looked around here, and i am sure this has been answered, but i don't understand it. The thing is, I have taken a introductory signal processing course, and we had to use Mathematica, and i had ... - asked by mickey (10 votes), answered by Vitaliy Kaurov (17 votes) ---------------------------- [Wikipedia People only search]\url{http://mathematica.stackexchange.com/questions/45393/wikipedia- people-only-search} I am trying to search people from Wikipedia(For example .*John.* in REGEX). The following query is close, but it isn't generalized like .*John.* and only gives back historic figures that have ... - asked by Liam William (8 votes), answered by Michael Hale (8 votes) ---------------------------- [Smoothing ListContourPlot contours]\url{http://mathematica.stackexchange.com/questions/45519/smoothin g-listcontourplot-contours} I have some data of type {{x1, y1, f1}, {x2, y2, f2}, ...} and want to do ListContourPlot. However, there is a problem that the data f is not smooth enough and has small errors. Here is a toy ... - asked by Yi Wang (7 votes), answered by Rahul Narain (8 votes) ---------------------------- [Half-delayed evaluation]\url{http://mathematica.stackexchange.com/questions/45361/half-d elayed-evaluation} In a certain wider context, I need to make some delayed definitions, such as x := a + b + c, but within these definitions I want a and b to be evaluated to their current values, not their later ... - asked by Dror Bar-Natan (7 votes), answered by WReach (5 votes) ================================== Greatest hits from previous weeks: ================================== [How do I plot coordinates (latitude and longitude pairs) on a geographic map?]\url{http://mathematica.stackexchange.com/questions/2076/how-do-i-plot -coordinates-latitude-and-longitude-pairs-on-a-geographic-map} I'm attempting for the first time to create a map within Mathematica. In particular, I would like to take an output of points and plot them according to their lat/long values over a geographic map. I ... - asked by Peter House (36 votes), answered by kguler (24 votes) ---------------------------- [What are the most common pitfalls awaiting new users?]\url{http://mathematica.stackexchange.com/questions/18393/what-are-t he-most-common-pitfalls-awaiting-new-users} As you may already know, Mathematica is a wonderful piece of software. However, it has a few characteristics that tend to confuse new (and sometimes not-so-new) users. That can be clearly seen from ... - asked by belisarius (134 votes), answered by Michael E2 (67 votes) ================================== Can you answer these? ================================== [How to not include data value outside plot range in the plot]\url{http://mathematica.stackexchange.com/questions/45537/how-to-not-i nclude-data-value-outside-plot-range-in-the-plot} Consider this list plot ls = Table[Sin[t], {t, 0, 100, 0.1}]; p = ListPlot[ls, PlotRange -> {{0., 0.1}, All}, DataRange -> {0, 1}, Joined -> True] If we look at the data in the plot, we ... - asked by xslittlegrass (2 votes) ---------------------------- [Finding undetermined coefficients with boundary conditions]\url{http://mathematica.stackexchange.com/questions/45219/findin g-undetermined-coefficients-with-boundary-conditions} I have 2 equations which are; To[x_] := c1 E^(-a1 x)/2 + c2 E^(a1 x)/2 + a2 Tu[x_] := c3 E^(-a3 x)/2 + c4 E^(a3 x)/2 Tu equals almost zero (10^-6) at end of the wires. To must be equal to Tu at ... - asked by CanYusuf (1 vote) ---------------------------- [Why does setting $Assumptions make my Fourier transforms slow?]\url{http://mathematica.stackexchange.com/questions/45258/why-does-se tting-assumptions-make-my-fourier-transforms-slow} Consider these Fourier transforms AbsoluteTiming[FourierTransform[Exp[(-I)*\[Omega]0*t]*Exp[-t^2], t, \[Omega]]; ] AbsoluteTiming[FourierTransform[Exp[(-I)*\[Omega]0*t]*Exp[-(t/T0)^2], t, \[Omega]]; ] ... - asked by xslittlegrass (2 votes)