[SciPy-user] Scipy vs Numpy rfft

[David Cournapeau]

Nick Fotopoulos wrote:
> Dear all,
>
> I was very surprised to find that on my machine (Intel Mac), a call to
> numpy.fft.rfft is many times faster (10-20x) than scipy.fftpack.rfft.
> I understand that their outputs require different unpacking, but I
> really only care about the speed here.  Is this a common problem?
> Scipy is linked against a universally built FFTW.  My input data
> length is a power of 2.
Does this happen for the first call only, or for many calls ? Could you 
give us a script which shows this behaviour ?

David