9.10.1 Top new questions this week

9.10.1.1 Can we explain why using `Nothing` twice on a list does not operate twice?
9.10.1.2 Speeding up Gaussian sampling
9.10.1.3 Why does Mathematica take so long to produce this sound?
9.10.1.4 Trace shows Linux has worse error than Windows in 1/(-1.)^1.2
9.10.1.5 Stacked NumberLinePlot?
9.10.1.6 Extracting list elements following a specific marker
9.10.1.7 Is there a bug in Eigensystem[]?
9.10.1.1 Can we explain why using `Nothing` twice on a list does not operate twice?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=282288

Below I generate a list of numbers between 1 and 15. I then set the value at position 10 to  Nothing  and as expected the value at position 10 is changed. This is as ... 
[functions]
 
asked by Hugh https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12558 Score of 15
answered by Domen https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=75628 Score of 20
9.10.1.2 Speeding up Gaussian sampling

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=282210

Edit Greg Hurst answers show how to independently get 3x speed-up using single-threaded MKL implementation and 4x speed-up by using native implementation with multi-threading, can they be combined? 
 
... 
[performance-tuning] [probability-or-statistics]
 
asked by Yaroslav Bulatov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=217 Score of 13
answered by Greg Hurst https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=4346 Score of 13
9.10.1.3 Why does Mathematica take so long to produce this sound?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=282381

Mathematica is behaving very slow, not like I could compare, as the speed has always been like this. The following ran in 58.64 seconds, is this normal? How can I speed it up? 
... 
[performance-tuning] [sound]
 
asked by Aarav Prasad https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=91851 Score of 8
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 Score of 10
9.10.1.4 Trace shows Linux has worse error than Windows in 1/(-1.)^1.2

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=282358

So I questioned why there are differences between Wolfram Cloud and Windows 11 Evaluate $\int_{0}^{\pi/2} \cos^a (x)\sin(ax) dx$ using Mathematica 
... 
[numerics] [number-representation]
 
asked by   https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=82985 Score of 7
answered by Henrik Schumacher https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=38178 Score of 8
9.10.1.5 Stacked NumberLinePlot?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=282236

Is there some built-in I can reuse to get a "stacked" number line plot? In other words, equivalent to  NumberLinePlot , but some numbers occur more than ... 
[plotting]
 
asked by Yaroslav Bulatov https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=217 Score of 7
answered by kglr https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=125 Score of 5
9.10.1.6 Extracting list elements following a specific marker

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=282306

I have a set of data (called  MyList ), and I need to extract every value that appears after a certain marker (in this case ... 
[list-manipulation]
 
asked by Schaef https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=86447 Score of 6
answered by user1066 https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=106 Score of 10
9.10.1.7 Is there a bug in Eigensystem[]?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=282357

Does  Eigensystem[]  produce incorrect output for symmetric matrices with integer components? 
The following eigensystem decomposition of a 12x12 matrix and its ... 
[eigenvalues]
 
asked by Rainer Glüge https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=18671 Score of 6
answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 Score of 11