numpy.fft() what is the return value amplitude + phase shift OR angle?
The magnitude, r, at a given frequency represents the amount of that frequency in the original signal. The complex argument represents the phase angle, theta.
x + i*y = r * exp(i*theta)
Where x and y are the numbers that that the numpy FFT returns.
The np.fft.fft() returns a complex array .... what is the meaning of the complex number ?
I suppose the real part is the amplitude !
The imaginary part is phase-shift ? phase-angle ? Or something else !
I figured out the position in the array represent the frequency.