[SciPy-user] Frequency content of a transient signal

Matthieu Brucher matthieu.brucher@gmail....
Tue Jul 22 07:37:01 CDT 2008


>  Hi Matthieu,
>
> I made some progress (See test_stft.py).
> But, how do I choose proper values for the parameter
> NFFT,noverlap ?
>
> Cheers,
>           Nils

Of course, if pylab has everything, it's better :D

This is what I think, I didn't try it much :
NFFT is the size of one slice, so if you want to compute the FFT over
25 ms, NFFT = 24. e-3 *400
noverlap depends on the size of the slice and the number of FFTs you
want per second. If you want 50 FFTs per second (50 colmuns per
second), that means one every actual 400/50 sample, noverlap is NFFT -
8

If someone knows better this, he can show himself ;)

Matthieu
-- 
French PhD student
Website : http://matthieu-brucher.developpez.com/
Blogs : http://matt.eifelle.com and http://blog.developpez.com/?blog=92
LinkedIn : http://www.linkedin.com/in/matthieubrucher


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