FFT

FFT

[Pascal Obry]

Do we have a good FFT (Fast Fourier Transform) implementation in Ada ?

Thanks,
Pascal.

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--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
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Re: FFT

[Jeff C]

Pascal Obry wrote:
> Do we have a good FFT (Fast Fourier Transform) implementation in Ada ?
> 
> Thanks,
> Pascal.
> 

I don't know of any great publically available ones. There is a binding 
to FFTW http://privatewww.essex.ac.uk/~sjs/fftw_ada/fftwa.html but the 
binding  is  released as pure GPL (not GMGPL) which would be somewhat ok 
since I think FFTW itself is also pure GPL. However, I believe you can 
buy a proprietary license for the FFTW library from MIT.


<SPECULATION>

I don't think you can buy a non pure GPL license for the Ada binding.

Documentation claims it is Copyright Stephen J. Sangwine but I suspect 
this is one of those things that is encumbered by some sort of 
university interest in it as well. If this is the same university as 
PNG_IO then I'd look elsewhere if you need something non GPL. Several 
years ago we tried to purchase a license for PNG_IO and after several 
months our purchasing deparment still was unable to get the office that 
dealt with this stuff to complete the deal. Eventually the schedule 
moved far enough along that we had to come up with an alternate approach.


</SPECULATION>


The FFTW library itself is pretty nice and complete so if you have no 
issues with the use of a GPL library/binding take a look.

Re: FFT

[Pascal Obry]

Jeff C <jcreem@yahoo.com> writes:

> The FFTW library itself is pretty nice and complete so if you have no issues
> with the use of a GPL library/binding take a look.

I think there is issues about this. This is not for a project of mine, so I'll
check with the right guys.

Thanks,
Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|              http://www.obry.net
--| "The best way to travel is by means of imagination"
--|
--| gpg --keyserver wwwkeys.pgp.net --recv-key C1082595

Re: FFT

[tmoran]

In addition to FFTW, there's also http://cr.yp.to/djbfft.html which
doesn't appear to have any restrictions.  It appears to be for very fast
computation of powers of two FFTs.  It's in very nasty C, though.  I have
here a package fft_pack with Glassman's algorithm for arbitrary N, but I
can't seem to track its provenance.  If speed isn't an issue, it's quite
convenient.  Numerical Recipes in Fortran (etc) has source and discussion
of various FFT situations.

Re: FFT

[Gautier]

# In addition to FFTW, there's also http://cr.yp.to/djbfft.html which
# doesn't appear to have any restrictions.  It appears to be for very fast
# computation of powers of two FFTs.  It's in very nasty C, though.  I have
# here a package fft_pack with Glassman's algorithm for arbitrary N, but I
# can't seem to track its provenance.  If speed isn't an issue, it's quite
# convenient.  Numerical Recipes in Fortran (etc) has source and discussion
# of various FFT situations.

Speaking of Numerical Recipes, you can pass the Pascal version,
available on the Web, through P2Ada which was improved for
that purpose.

-> http://www.mysunrise.ch/users/gdm/gsoft.htm#p2ada

HTH
______________________________________________________________
Gautier     --     http://www.mysunrise.ch/users/gdm/index.htm
Ada programming -- http://www.mysunrise.ch/users/gdm/gsoft.htm

NB: For a direct answer, e-mail address on the Web site!

Re: FFT

[Pascal Obry]

gautier_niouzes@hotmail.com (Gautier) writes:

> Speaking of Numerical Recipes, you can pass the Pascal version,
> available on the Web, through P2Ada which was improved for
> that purpose.

Yep, we have this possibility indeed.

Thanks,
Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|              http://www.obry.net
--| "The best way to travel is by means of imagination"
--|
--| gpg --keyserver wwwkeys.pgp.net --recv-key C1082595

Re: FFT

[Pascal Obry]

tmoran@acm.org writes:

> In addition to FFTW, there's also http://cr.yp.to/djbfft.html which
> doesn't appear to have any restrictions.  It appears to be for very fast
> computation of powers of two FFTs.  It's in very nasty C, though.  I have
> here a package fft_pack with Glassman's algorithm for arbitrary N, but I
> can't seem to track its provenance.  If speed isn't an issue, it's quite
> convenient.  Numerical Recipes in Fortran (etc) has source and discussion
> of various FFT situations.

I don't think speed is really an issue for now. Is it standalone ? I found one
on the net (don't have the name now) but it required some other packages...
Anyway, I'll be glad to have a look. Thanks.

Pascal.

-- 

--|------------------------------------------------------
--| Pascal Obry                           Team-Ada Member
--| 45, rue Gabriel Peri - 78114 Magny Les Hameaux FRANCE
--|------------------------------------------------------
--|              http://www.obry.net
--| "The best way to travel is by means of imagination"
--|
--| gpg --keyserver wwwkeys.pgp.net --recv-key C1082595