Program fseries.m sums the real Fourier series for several different 
     functions using their exactly computed Fourier coefficients.  
     There are four different functions "built in" to the program fseries.


     Program fast.m uses the fft to compute the DFT approximations to the
     complex Fourier coefficients c_k. It further adds up the
     partial sums and plots the real part of the partial sum against
     the original function f, which must be given in an mfile f.m.

     Program ftrans.m uses the fft to compute the Fourier transform
     of a function f, given in the mfile f.m.  It also plots the 
     real part and imaginary part of fhat (as computed using the fft).