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Hanning window of MATLAB

  1. Feb 22, 2012 #1
    Hi all

    As far as I know Hanning window is defined as the following:
    .5+.5*cos(2*pi*n/N) and n is between [-(N-1)/2,(N-1)/2] here N is odd number.

    MATLAB functions "hanning" with symetric or periodic options or "hann" do not match with the results of the above formula. There is always a slight annoying difference !

    Do you know the problem?

    (Same thing for Hamming window)
  2. jcsd
  3. Feb 22, 2012 #2


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    Gold Member

  4. Feb 23, 2012 #3
    As I understand the book is wrong (Notes On Digital Signal Processing by C. Britton Rorabaugh). If I replace the N by (N-1) in the denumerator of the formulation which is 5+.5*cos(2*pi*n/(N-1)), the results coincide exactly with that of MATLAB.

    Thank you for the link.
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