MATLAB: Hanning window

MATLABwindow

Hello,
what is the difference between hanning and hann? They are both supposed to be returning hanning window sequences.
-obli

Best Answer

The Hann and Hanning window are both implemented in MATLAB by the same basic equation
w = 0.5 - 0.5*cos(2*pi*x);
There is a slight difference in the way they are calculated in hann.m and hanning.m based on the "x" vector that is evaluated in that equation.
For hann.m
hann(5) gives you
x = (0:2)'./4;
w = 0.5 - 0.5*cos(2*pi*x);
w = [w ; w(end-1:-1:1)]
whereas hanning(5) gives you
x = (1:3)'./6;
w = 0.5-0.5*cos(2*pi*x);
w = [w ; w(end-1:-1:1)];
Since the time vector in hann.m starts with 0, you get 0 as the first and last sample with hann.m, but not with hanning.m which starts with 1 as the first element of the time vector.
But they are the same equation and I think you can use which every implementation you want.
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