[SciPy-user] FFT speed ?

[Samuel GARCIA]

Hello list,

I have a problem with fft speed.
could someone try this :

from scipy import *
import time

a = rand((186888));t1=time.time();fft(a);t2=time.time();t2-t1

# for me about 0.67791390419006348 s. on centrino 1.6GHz

a = rand((186890));t1=time.time();fft(a);t2=time.time();t2-t1

# for me about 1.622053861618042 s. on centrino 1.6GHz

a = rand((186889));t1=time.time();fft(a);t2=time.time();t2-t1

# the computation is infinit !!!! (no time to wait)


Question : why is there a problem specialy for that size (186889) of fft ?
It is not the only size with that problem.


Thank

Sam


-- 
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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
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