MATLAB: Median Frequency(Fmed)

Question

I need help finding the Median frequency of a power spectram. (Fmed), I am new to matlab so any helo will be really appreciated.

Answer 1

Hi Shenal, you can do the following:

   t = 0:0.001:1-0.001;
   x = cos(2*pi*50*t-pi/4)+0.5*sin(2*pi*100*t)+randn(size(t));
   psdest = psd(spectrum.periodogram,x,'Fs',1000,'NFFT',length(x)); 
   normcumsumpsd = cumsum(psdest.Data)./sum(psdest.Data);
   Ind = find(normcumsumpsd <=0.5,1,'last');
   fprintf('Median frequency is %2.3f Hz\n',psdest.Frequencies(Ind));