How to implement rectangular and welch window in MATLAB to plot fft respectively?
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Hello Everybody,
I just want to know that how to implement rectangular and welch window in MATLAB to plot fft? And i want to know that what will be the effect if i do not use these in our fft? I have written the following code so please suggest how to specify rectangular and welch window in this code.
I = load('data1.asc');
for i = 1:2048
x = I(:,2);
end
Fs = 40;
t = 0:1/Fs:(2e3*1/Fs)-1/Fs;
T = 1/Fs;
L = 2048;
NFFT = 2^nextpow2(L);
Y = abs(fft(x,NFFT))/L;
f = Fs/2*linspace(0,1,NFFT/2+1);
plot(f,2*abs(Y(1:NFFT/2+1)))
axis([0 50 0 40])
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Answers (2)
Honglei Chen
on 23 Jul 2013
Rectangular window is the same as no window. For Welch window, you can find it on file exchange at
(Disclaimer: I haven't personally used it so I cannot comment on its quality)
If you have a window, w, you just need to do the following in your code instead:
Y = abs(fft(x.*w,NFFT))/L;
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Deyan Dobromirov
on 7 Feb 2021
The implementation fails to create zeros at both ends. Here is my version:
function w = welchwin(n)
m = floor(n/2); k = (0:m-1)';
w = 1 - (2*k/n - 1).^2;
if(mod(n, 2) ~= 0), w = [w; 1]; end
w = [w; flipud(w(1:m, 1))];
end
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