[SciPy-user] FFT speed ?

Samuel GARCIA sgarcia@olfac.univ-lyon1...
Wed Feb 7 09:05:18 CST 2007


Ok sorry.
I answered without trying !
Thank a lot.
I will solve that way.

Sam


Stefan van der Walt wrote:
> On Wed, Feb 07, 2007 at 03:18:19PM +0100, Samuel GARCIA wrote:
>   
>> yes I was thinking of doing something like that but
>> fft(a,pow(2,18)).shape is of course 262144 (2**18)
>> and when I use ifft after that The length of my signal have changed I have an
>> interpolated signal ... new problem for me ...
>>     
>
> An interpolated signal?
>
> In [19]: N.real(N.fft.ifft(N.fft.fft(N.arange(11),16)))
> Out[19]: 
> array([  0.,   1.,   2.,   3.,   4.,   5.,   6.,   7.,   8.,   9.,  10.,
>         -0.,   0.,   0.,   0.,   0.])
>
> Padding in the Fourier-domain, on the other hand:
>
> In [20]: N.real(N.fft.ifft(N.fft.fft(N.arange(11)),16))
> Out[20]: 
> array([ 0.        ,  2.10035464,  3.04455839,  1.35780382,  3.23688237,
>         3.12291155,  2.35790278,  4.12133152,  3.4375    ,  3.29213721,
>         5.00323313,  3.69035768,  4.32561763,  5.98165513,  3.3443057 ,
>         6.58344845])
>
>
> Cheers
> Stéfan
> _______________________________________________
> SciPy-user mailing list
> SciPy-user@scipy.org
> http://projects.scipy.org/mailman/listinfo/scipy-user
>   

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Samuel Garcia
Universite Claude Bernard LYON 1
CNRS - UMR5020, Laboratoire des Neurosciences et Systemes Sensoriels
50, avenue Tony Garnier
69366 LYON Cedex 07
FRANCE
Tél : 04 37 28 74 64
Fax : 04 37 28 76 01
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://projects.scipy.org/pipermail/scipy-user/attachments/20070207/4278b361/attachment.html 


More information about the SciPy-user mailing list