[SciPy-dev] Single precision FFT

[David Cournapeau]

Anne Archibald wrote:
>
> Make sure they're adequately boring.
>   

Note that I did not say they were boring, but shamefully, my Japanese is
sill poor enough such as formal presentations mostly elude me :)

I fixed fft such as the complex transform handles complex numbers with 0
imaginary output - effectively making fft of float32 array work in
single precision. I also discovered at the same time that fftpack has
some cosine and sine transforms, which is great - I will be able to
implement some missing functions compared to the matlab signal toolbox
easily with this.

I discovered something weird - though unrelated: real fft (rfft) in
numpy and scipy are different in their output format (numpy puts only
one 'side' of the hermitian output - scipy put all the number in an
array of reals, which is a bit strange). I don't think the scipy format
makes much sense ? In C, I can see the advantage of having input/output
of the same type/size, but in python, I am not sure. Modifying this
would be a major breakage, though,

cheers,

David