can i see the code of built in matlab function?

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

[Walter Roberson]

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 .

[Maaz Rao]

what are the two significant implentations?

[Walter Roberson]

https://www.mathworks.com/matlabcentral/fileexchange/3026-rainflow-counting-algorithm and https://www.mathworks.com/matlabcentral/fileexchange/68176-rainflow-counting-as-per-1-astme-and-2-endo

[Maaz Rao]

actually i want to extract cycles from a random sound wave and then apply rainflow on it how can i do that?

[Walter Roberson]

Sorry, I am not familiar with that topic.