Say you have a function like:
data=4/(1+0.2Cos[2 Pi t/NN])
I used the following command to plot a spectrum:
ListPlot[Abs[Fourier[data]], Plot Range->All,
The problem is that this does not give me a spectrum plotted on the frequency axis (Hz).
So, I was wondering how do I plot a spectrum graph with the horizontal axis being the frequency (Hz)