6.31.3 Can you answer these questions?

6.31.3.1 Periodical sum of rows by a certain step

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}] 
... 
[matrix] [summation] [row]
 

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

6.31.3.2 Behavior of $MinPrecision seems to have changed between 12.0.0 and 12.1.1

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 ... 
[warning-messages] [precision-and-accuracy] [version-12.1]
 

asked by Kvothe https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=45020 3 votes

6.31.3.3 HankelTransform problem

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 ... 
[integral-transforms]
 

asked by SolutionExists https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=70331 1 vote