[Numpy-discussion] fftpack_lite question

[Sturla Molden]

Ralf Gommers skrev:
>
> If anyone with knowledge of the differences between the C and Fortran 
> versions could add a few notes at the above link, that would be great.
>
The most notable difference (from a user perspective) is that the 
Fortran version has more transforms, such as discrete sine and cosine 
transforms. It also supports single and double precision. The older 
Fortran version is used in SciPy.

FFTs from FFTW and MKL tend to be faster than FFTPACK, at least on Intel 
hardware. FFTPACK was originally written for running fast on vector 
machines like the Cray and NEC.

FFTPACK-lite:
http://projects.scipy.org/numpy/browser/trunk/scipy/basic/fftpack_lite?rev=1676

Older Fortran version:
http://www.netlib.org/fftpack/

Fortran 90 version (no license):
http://orion.math.iastate.edu/burkardt/f_src/fftpack/fftpack.html

Another C version:
http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=fftpack/fft.c 
<http://www.netlib.org/cgi-bin/netlibfiles.txt?format=txt&filename=fftpack/fft.c>




S.M.