7.2.1 Top new questions this week

7.2.1.1 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 ... 
[performance-tuning] [computational-geometry] [code-review]
 

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

7.2.1.2 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? 
[core-language] [expression-test] [compatibility] [upvalues]
 

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

7.2.1.3 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 ... 
[graphics] [bugs] [pdf-format] [printing]
 

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

7.2.1.4 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" (... 
[plotting] [bugs] [chemistry]
 

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

7.2.1.5 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 ... 
[debugging] [echo]
 

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

7.2.1.6 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 ... 
[function-construction] [expression-manipulation] [compile] [scoping]
 

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

7.2.1.7 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 : 
... 
[image-processing]
 

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