8.20.3 Can you answer these questions?

8.20.3.1 Kernel crash with RandomChoice
8.20.3.2 How to convert a PDE from cartesian to spherical coordinates?
8.20.3.3 Data visualization in Mathematica (1000 x 1000 square)
8.20.3.1 Kernel crash with RandomChoice

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=269804

Bug existing since version 8.0.4 and persisting through 13.0.1 or later 
I use Mathematica 12.3.1 for Microsoft Windows (64 bit). While playing with some code inspired by this recent question, I ... 
[bugs] [random] [crash]
 
asked by MarcoB https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=27951 Score of 4
8.20.3.2 How to convert a PDE from cartesian to spherical coordinates?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=269586

I am investigating solutions to $\Delta u - x\cdot \nabla u=0$ in $\mathbb{R}^n$ and I would like to convert this equation from cartesian to spherical coordinates in mathematica. How should I go about ... 
[differential-equations] [coordinate-transformation]
 
asked by Student https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=85212 Score of 1
8.20.3.3 Data visualization in Mathematica (1000 x 1000 square)

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=269699

I'm currently interested in looking at all the 6-digit numbers in base 10 (i.e. 000000 to 99999), and checking if they satisfy at least one of 5 equations: either 0=0+0+0+0+0, 0+0=0+0+0+0,..., 0+0+0+0+... 
[visualization] [modular-arithmetic]
 
asked by Haines https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=87055 Score of 2