function Px = ev(x,p,M)%EV	Frequency estimation using the eigenvector method%--%USAGE	Px = ev(x,p,M)%%	The input sequence x is assumed to consist of p complex%	exponentials in white noise.  The frequencies of the%	complex exponentials and the variance of the white noise%	are estimated using the eigenvector method.  %%	x : input sequence%	p : Number of complex exponential in x%	M : Size of the autocorrelation matrix to use in%	      estimating the complex exponential frequencies%%	The frequency estimates are found from the peaks of the%	pseudospectrum Px.%%  see also PHD, MUSIC, and MIN_NORM%%---------------------------------------------------------------% copyright 1996, by M.H. Hayes.  For use with the book % "Statistical Digital Signal Processing and Modeling"% (John Wiley & Sons, 1996).%---------------------------------------------------------------   x   = x(:);   if N<p+1, error('Specified size of R is too small'), end   R = covar(x,N);   [v,d]=eig(R);   [y,i]=sort(diag(d));   Px=0;   for j=1:N-p       Px=Px+abs(fft(v(:,i(j)),1024)).^2/abs(y(j));       end;   Px=-10*log10(Px);   end;