how to use a function in another m file

I'm writing a code to calculate the fourier series. I need help for calling a function that I've created in another m file.

[dpb]

In what way do you need help? One simply refers to the user-generated m-file by its name just as any other Matlab function. Only thing, of course, is that you must have saved the m-file in a location which is on the MATLABPATH search directory and with the name spelled correctly (including capitalization, Matlab is case-sensitive) for the name to be resolved and the function found.