gusucode.com > 声音的处理有：LPC，FFT，共振峰，频谱源码程序 > siganlandsystemusingMatlab/SSUM/library/spec_centroid.m

    function sc_value = spec_centroid(signal,Fs)

	FFT = fft(signal);
	mag = abs(FFT);
	mag = mag(1:length(mag)/2);
	num = 0;
	den = 0;

	for i=1:length(mag),
		num = num + mag(i)*(i-1);
		den = den + mag(i);
	end

	Hz_per_bin = Fs/length(signal);
	sc_value = Hz_per_bin*num/den;