Re: interesting FFT benchmarking!

[Geraint Paul Bevan]

address@hidden wrote:
>
> Anybody has any idea of what is going on here? Octave transforms complex
> signals as fast as Matlab transforms real signals, and transforms real
> signals as slow as matlab does with complex signals!! Why isn't the
> transform from real signals faster in octave?...
>

I may be wrong, but I think you'll find that Octave converts real data
into complex data before performing a Fourier transform.

If you look in liboctave/oct-fftw.h, you will notice that there is no
declaration for octave_fftw involving real matrices.

An additional clue is the fact that only the complex variants of fftpack
are present in libcruft/fftpack.

--
Geraint Bevan
Department of Mechanical Engineering
University of Glasgow
Tel: +44 (0)141 330 5917



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