the fft function in matlab gives a theoretical mathematical fft of the signal, and is not scaled to units and is real immaginary and not amplitude-frequency
I think in better terms, I want to plot the amplitude spectrum of the signal,, with the X axis being the frequencies of the input signal.
is there an alternative way of fft to do this ? and is the following link correct?
for example if this is my signal
using the code in the link I get
which its extremums do not meet the extremums of the time signal