> > "By far the most common FFT is the Cooley-Tukey algorithm. This is a divide > > and conquer algorithm that recursively breaks down a DFT of any composite Steven Lehar gives what I consider the best (most accessible) description "An Intuitive Explanation of Fourier Theory " http://cns-alumni.bu.edu/~slehar/fourier/fourier.html Including a few paragraphs on the Optical Fourier transform (purely analogue: using light!) I've repeated his results using Excel for what it's worth ... Bob
