What are the outputs of FFT?
These frequencies actually represent the frequencies of the two sine waves which generated the signal. The output of the Fourier transform is nothing more than a frequency domain view of the original time domain signal.
What does a FFT graph show?
Frequency-domain graphs– also called spectrum plots and Fast Fourier transform graphs (FFT graphs for short)- show which frequencies are present in a vibration during a certain period of time.
How to plot FFT output in MATLAB?
Y = fft(X); Compute the single-sided amplitude spectrum of the signal. f = Fs*(0:(L-1)/2)/L; P2 = abs(Y/L); P1 = P2(1:(L+1)/2); P1(2:end) = 2*P1(2:end); In the frequency domain, plot the single-sided spectrum.