FFTCentroid Spectral centroid

FFTCentroid.kr(chain)

Given an FFT chain, this measures the spectral centroid, which is the magnitude-weighted mean frequency, or the "centre of mass" of the spectrum. (DC is excluded.)

This can be a useful indicator of the perceptual brightness of a signal.

Example

// Very artificial example - just filtering some noise.

s.boot;

b = Buffer.alloc(s,2048,1);

(

x = {

var in, chain, freq, rq, centroid;

//freq = LFPar.kr(0.3).exprange(100, 1000);

freq = MouseY.kr(1000, 100, 1);

rq = MouseX.kr(0.01, 10);

in = BPF.ar(WhiteNoise.ar, freq, rq);

chain = FFT(b.bufnum, in);

centroid = FFTCentroid.kr(chain);

Out.ar(0, in.dup * 0.1);

centroid.poll(10);

}.play(s);

)

x.free;