powerspectrum.m

matlab source code very useful to science study

function [m]=PowerSpectrum()
%global x;
%Original Signal 
global y; 
%Noisy Signal
if (isempty(y)) 
m =[];
return;
end
f=1000*(0:256)/512;
y = fft(y,512);
Pyy=y.* conj(y)/512;
subplot(212)
plot(f,Pyy(1:257))
title('Frequency content of y')
xlabel('frequency (Hz)')
m=Pyy;