What is the updated version of FFT that does not require 2^n data points?

[Dr.D]

Back when I studied the FFT (many years ago), it was always described as transforming a sample based on 2^n data points. More recently, I have read that this restriction has been removed. Can anyone point me to a good reference on this newer form, preferably something available free on the 'net since I have very limited library access? Any comments on this will be much appreciated.

 

[Dr Transport]

FFTW... http://www.fftw.org/

 

[cris]

The 2^n restriction is for a specific algorithm. The fftw and the accelerated libraries like cufft they different algorithms now which allow a wide combination of prime integers. In general I try use only numbers which combinations of powers of only 2,3 and 5.

 

[Dr.D]

Thank you, Dr Transport & Chris.