[SciPy-User] Is the second half of np.fft.fft the negative frequencies?

[Robert Kern]

On Wed, Aug 31, 2016 at 8:11 AM, Matti Viljamaa <mviljamaa at kapsi.fi> wrote:
>
> I’m having the following problem
>
>
http://dsp.stackexchange.com/questions/33982/problem-with-windowing-method-result-seems-shifted
>
> My question is:
>
> in
>
> http://i.stack.imgur.com/fYFvx.png
>
> are samples [0, 512] the positive frequencies and [513, 1024] the
negative frequencies (in two-sided FFT).
> I.e. that to be correct the plot should actually look like [513, 1024] is
[-512, 0] and [0,512] is [0,512], but is this the np.fft.fft way to return
the negative frequencies (i.e in the latter half of the fft result)?

Yes, this is a standard convention used by many (most?) FFT implementations.

http://docs.scipy.org/doc/numpy/reference/routines.fft.html#implementation-details

--
Robert Kern
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