What do you call "many"?
Think would need a lot more description of what you're actually trying to model to have any real input...but in general, one can either compute those quantities that can be defined programmatically with some algorithm or read files of essentially any format one wishes to create ('LOAD/SAVE' are particularly convenient/easy in MATLAB if you have the data in ML from somewhere first) or hardcode in constants as arrays or other higher-level abstractions in one or more m-files that are called as functions to return their values. Something like 'pi' is a builtin function that simply returns a constant. The problem with that solution can be one of how many return variables one may need in the calling function.
IOW, "it all depends..."
