Here is a collection of FFT programs that appeared in S.Mitra&J.Kaiser: Handbook in Digital Signal Processing, John Wiley & Sons, 1993, ISBN 0-471-61995-7. thanks to Henrik Sorensen for the code ! thanks to John W. Herman for the pointer to Henrik Sorensen :) this is also avialable at ftp://ftp.teleos.com/VISION-LIST-ARCHIVE/SHAREWARE/CODE/FFT/FFT.shar