[SciPy-user] fftw, scipy ("old") install

Arnd Baecker arnd.baecker at web.de
Mon Oct 17 15:15:32 CDT 2005

On Mon, 17 Oct 2005, Fernando Perez wrote:

> On Oct 17, 2005, at 4:29 AM, Pearu Peterson wrote:
> > Oops, indeed, the patch for fftw3 is already applied. But I haven't
> > tested it yet. Looking at system_info.py, get_info('fftw') still looks
> > for
> > only fftw2 libraries. So, fftw3 support needs to be finished.
> If I recall correctly, an fftw3 patch was sent this summer by a user,
> and I applied it (back n the old_scipy CVS days).  That patch actually
> had a bug in it, but I think you fixed the bug without reverting it, so
> the core fftw3 support should already be in  (though it may still need
> some polishing).

Hmm, but it did not work for me, it seems.
Maybe I did something wrong
(not building the right fftws etc?)

OTOH, site-packages/scipy/config.py has

fftw_info={'libraries': ['fftw3'], 'library_dirs': ['/scr/python/lib'],
'define_macros': [('SCIPY_FFTW3_H', None)], 'include_dirs':

OK, it seems to be not my day:
  nm _fftpack.so | grep fftw
*does* show quite a few entries involving fftw
(I have no idea what I grepped this morning ...)

I am a bit puzzled now and see the following possibilities
- for my build scipy  does not use the fftw
- I should have given some more flags when building fftw3
  (including optimization)
  With my build it only created:
    libfftw3.a and libfftw3.la
  (Moving these out of the way does not change anything...)
- some weird slow down on the opteron

Alright, I will have to do further and better checking
tomorrow - sorry for creating noise....

Best, Arnd

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