for your info: ch. 11 mbe: fast fourier transforms

On different variations of fft:
I think it's best to introduce an option, with which you can select  
what normalisation you want. Look at
http://documents.wolfram.com/mathematica/functions/Fourier

For the default I would recommend the same definition of DFT and  
inverse DFT that Wikipedia states. Then inexperienced users would get  
what they expect, while expert users could configure the fft to suit  
their specific needs.

It would be nice to have fourier_DCT and fourier_DST also (sine and  
cosine transforms) - not hard to do once you have fft going..

Also, what about arrays which are not of length 2^n? Is this too  
complicated to do? Ofcourse, this can also be added at a later time  
(without breaking existing maxima programs).

Regards,
Ziga Lenarcic