28 Oct
2014
28 Oct
'14
6:11 a.m.
David Cournapeau
The real issue with fftw (besides the license) is the need for plan computation, which are expensive (but are not needed for each transform).
This is not a problem if you thell FFTW to guess a plan instead of making measurements. FFTPACK needs to set up a look-up table too.
I made some experiments with the Bluestein transform to handle prime transforms on fftpack, but the precision seemed to be an issue. Maybe I should revive this work (if I still have it somewhere).
You have it in a branch on Github. Sturla