Power Spectrum Estimation (non-parameteric methods): per(x,n1,n2) - File Exchange

No BSD License

from Power Spectrum Estimation (non-parameteric methods) by payam masoumi
there is a simple demo for non parameteric spectral estimation methods

per(x,n1,n2)
function Px = per(x,n1,n2) x = x(:); if nargin == 1 n1 = 1; n2 = length(x); end; Px = abs(fft(x(n1:n2),1024)).^2/(n2-n1+1); Px(1) = Px(2);