I'm looking for some fft code that has:
1. commercial-friendly license 2. seperates construction (which involves costly trig functions) from repeated use (which should use only multiply-add) An example of (2) is fftw, but that doesn't meet (1). I've seen plenty of examples that have (1) but not (2) - these use fft as a function, which has no state. fft should be written as a class, where in the constructor all the trig functions are determined. _______________________________________________ SciPy-User mailing list [hidden email] http://mail.scipy.org/mailman/listinfo/scipy-user |
And even FFTW has not a real 2 anymore with the 3.0 API. Although the construction is only really costly the first time you build a plan, you have to create them with the actual input and output array pointers! Matthieu 2013/4/17 Neal Becker <[hidden email]> I'm looking for some fft code that has: Information System Engineer, Ph.D. Blog: http://matt.eifelle.com LinkedIn: http://www.linkedin.com/in/matthieubrucher Music band: http://liliejay.com/ _______________________________________________ SciPy-User mailing list [hidden email] http://mail.scipy.org/mailman/listinfo/scipy-user |
In reply to this post by Neal Becker
On 04/17/2013 09:08 AM, Neal Becker wrote:
> I'm looking for some fft code that has: > > 1. commercial-friendly license > 2. seperates construction (which involves costly trig functions) from repeated > use (which should use only multiply-add) > > An example of (2) is fftw, but that doesn't meet (1). > > I've seen plenty of examples that have (1) but not (2) - these use fft as a > function, which has no state. fft should be written as a class, where in the > constructor all the trig functions are determined. > > _______________________________________________ > SciPy-User mailing list > [hidden email] > http://mail.scipy.org/mailman/listinfo/scipy-user doesn't meet your need the FFTW folks maintain an quite extensive list of FFT implementations, http://www.fftw.org/benchfft/ffts.html and http://www.fftw.org/benchfft/ffts.html. One of those may be what you are looking for. Also, FFTW can be licensed for commercial use for a fee, http://web.mit.edu/tlo/www/industry/fftw-1.html. - Jonathan Helmus _______________________________________________ SciPy-User mailing list [hidden email] http://mail.scipy.org/mailman/listinfo/scipy-user |
In reply to this post by Neal Becker
Hi Neal,
On Wed, Apr 17, 2013 at 9:08 AM, Neal Becker <[hidden email]> wrote: > I'm looking for some fft code that has: > > 1. commercial-friendly license > 2. seperates construction (which involves costly trig functions) from repeated > use (which should use only multiply-add) > > An example of (2) is fftw, but that doesn't meet (1). > > I've seen plenty of examples that have (1) but not (2) - these use fft as a > function, which has no state. fft should be written as a class, where in the > constructor all the trig functions are determined. I believe the code in the numpy.fft module sort of does this -- uses fftpack, and automatically calls the initialization routine (cfftfi) and caches the result for subsequent calls with the same array length. You don't actually need to make an explicit call to cfftfi(), as you would with C/Fortran, but this routine is only called once (per array length). See https://github.com/numpy/numpy/blob/master/numpy/fft/fftpack.py#L55 --Matt Newville <newville at cars.uchicago.edu> _______________________________________________ SciPy-User mailing list [hidden email] http://mail.scipy.org/mailman/listinfo/scipy-user |
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