Useful link about the implementation of FFT in Matlab.

http://www.ele.uri.edu/~hansenj/projects/ele436/fft.pdf

Also, here they talk about the amplitudes, very useful:

Useful link about the implementation of FFT in Matlab.

http://www.ele.uri.edu/~hansenj/projects/ele436/fft.pdf

Also, here they talk about the amplitudes, very useful: