i Have the following code;
Fs = 500;t = 0:1/Fs:10-1/Fs; s = cos(2*pi*15*t - 30) + cos(2*pi*40*t +60); NFFT=length(s); ft =(1/NFFT)*fft(s); freq = Fs*(0:(NFFT/2))/NFFT; Am=abs(ft); tol = 1e-6; ft(abs(ft) < tol) = 0; Ph = angle(ft); Am = Am*2; Am = Am'; Am = Am(1:end/2,:); freq = freq'; freq = freq(1:end-1,:); Ph=Ph'; Ph = Ph(1:end/2,:); plot(freq,Ph*(180/pi));
How do i interpretend the phase of this signal? shouldnt the phase plot give me -30° at 15Hz and 60° at 40Hz? How does it come that the fft gives 81.13° and -162.3°?
Kind regards
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