7.20.3 Can you answer these questions?

7.20.3.1 How to digitize a vector field?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=249430

Is there some way that I can digitize both the direction and the magnitude of a vector field accessible in JPEG format? 
To clarify what I mean, I want to have the numerical value of: 1)magnitude and 2)... 
[image-processing] [vector] [map] [digitization]
 

asked by MASOUD MOEINI https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80469 2 votes

7.20.3.2 Problem of color and solid mesh style of two surfaces in 3D plot

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=249160

I would like to plot two surfaces in the same figure using the following code. 
... 
[plotting]
 

asked by Guang-Le Du https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=80353 2 votes

7.20.3.3 Shortcut to execute previous statement again?

https://mathematica.stackexchange.com/landing/r/digest?cta=question&id=249343

Often I'll have a block that runs something like a random test, and I'll want to run it maybe a couple dozen times by hand, tweaking as necessary. I'd like to be able to hit some key or shortcut to re-... 
[keyboard]
 

asked by Trev https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=52996 2 votes

answered by Szabolcs https://mathematica.stackexchange.com/landing/r/digest?cta=user&id=12 0 votes