================================== 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)