MATLAB: Can i see the code of built in matlab function

Question

i want to know how the code of a built in function works where can i see it

secondly there is a function raainflow in signal processing tooolbox under vibratiion analysis under fatigue analysis how do i use it do i have to have the latest version of matlab installed how do i install the specific toolbox for this and can it run on an older version

Answer 1

In order to see the code of a built in function you need to be hired by Mathworks or else have several billion dollars to buy the entire company .

The rainflow you found needs Signal Processing Toolbox r2017b or later.

If you look in the file Exchange there are at least two significant rainflow implementations .