[Numpy-discussion] Normalization of ifft

Gideon Simpson simpson@math.toronto....
Thu Mar 26 21:02:26 CDT 2009

I thought it was the same as the MATLAB format:


On Mar 26, 2009, at 7:56 PM, Lutz Maibaum wrote:

> Hello,
> I just started to use python and numpy for some numerical analysis. I
> have a question about the definition of the inverse Fourier transform.
> The user gives the formula (p.180)
>  x[m] = Sum_k X[k] exp(j 2pi k m / n)
> where X[k] are the Fourier coefficients, and n is the length of the  
> arrays.
> The online documentation
> (http://docs.scipy.org/doc/numpy/reference/routines.fft.html), on the
> other hand, states that there is an additional factor of 1/n, which is
> required to make ifft() the inverse of fft(). Is this a misprint in
> the user guide?
>  Lutz
> _______________________________________________
> Numpy-discussion mailing list
> Numpy-discussion@scipy.org
> http://mail.scipy.org/mailman/listinfo/numpy-discussion


More information about the Numpy-discussion mailing list