calculate the frequency where psd is maximun

hi i am new in matlab and i want to calculate

"the percent power content around the dominant frequency" that dominant frequency is

_"the frequency where the power spectral density (PSD) is maximum"_this process will work on ECG signal.

thank you very much

Answer 1

[Wayne King]

Hi, one thing you can do is to obtain a periodogram and then calculate the average power in an interval around the maximum frequency and then compare that to the average power from 0 to the Nyquist.

   Fs = 1e3;
   t = 0:1/Fs:1-(1/Fs);
   x = cos(2*pi*100*t)+randn(size(t));
   psdest = psd(spectrum.periodogram,x,'Fs',1e3,'NFFT',length(x));
   [mx,I] = max(psdest.Data);
    relperc = ...
    100*avgpower(psdest,[psdest.Frequencies(I-2) psdest.Frequencies(I+2)])/avgpower(psdest,[0 Fs/2])

Wayne