1.17 Thursday, January 14, 2021

1.17.1 Top new questions this week

Faster "Closest Pair of Points Problem" implementation?

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

Broken ValueQ function in Mma12.2?

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

Graphics not correctly produced when saving to PDF in Version 12

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

MoleculePlot draws sucrose benzoate with overlapping bonds

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

How to globally disable and re-enable Echo?

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

Compile - Optimization of function calls - does it matter?

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

neighbouring pixels : next smaller and bigger perimeter

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

1.17.2 Greatest hits from previous weeks

How to make Jacobian automatically in Mathematica

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

Plotting Complex Quantity Functions

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

QR Code in shopping cart handle

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

How do I plot a plane EM wave?

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

Standard deck of 52 playing cards in curated data?

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

Why I get the "Set::write: "Tag Times in is Protected." error?

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

Mathematica vs. Python - how does Mathematica compare to Python’s scientific computing suite?

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

1.17.3 Can you answer these questions?

NDSolve - interpolation or machine precision problem

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

Matrix regularization, how to pick \(\lambda \)

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

Memory consuming Expand

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