Finding the second peak

[Star1976]

Hi
I am facing a trouble in locating the second maximum peak in FFT spectrum. I used the following to find the maximum peak but was not able to find the second peak..

X = abs(fft(Ei));
X = fftshift(X);
Peak = find(X == max(X));

Any help is appreciated !!!

 

[SomptingGuy]

Assuming you aren't looking for local maxima (i.e. the second highest local maxima), just sort X:

[Xs,idx]=sort(X);

Peak1 = idx(1)
Peak2 = idx(2)