# Harmonic amplitude spectrum

I have simulated an electrical machine in mathematica in discrete calculus. One of the results is three phase currents. My plotted answer is like below:

Now I'm looking for harmonic amplitude spectrum of the current of any of phases, for instance phase A like following figure:

I should mention that as all my simulations are in discrete calculus the phase current answer is a vector like:

ia={0, 0., -0.548775, <<14995>>, 11.4906, 10.9900, 11.1094}