[Gretl-users] How to look up code "behind" commands and functions

Hi I am new to gretl and I am trying to find out how the calculations behind different commands are done. For example, if I run the pca command I would like to see how exactly the eigenvectors are multplied with my data and how the data is standardized etc.. This also applies to the princomp function. Is it possible to look "into" these commands and functions or would I have to resort to some source code in C? Thanks, Andy