I am a high school physics teacher and was thinking of demonstrating to students how frequencies of complex waveforms such as notes of instruments can be identified using a Fourier transform.(adsbygoogle = window.adsbygoogle || []).push({});

I haven't done Fourier transforms for a while and was quickly re-reading about them earlier this evening.

Essentially what I was after is given some data (collected using a data logger and microphone etc) or as an example a series of points generated from t=0 to t=10 in steps of 0.1 of 2 Sin[x + 1] + 2 Sin[3 x] + 2 Sin[4.6 x + 3]. Plotting this in Mathematica gives me a nice looking waveform.

If I then do a Fourier transform on the data produced using Fourier[data], Mathematica produces a Table of complex numbers.

Can someone please help me take these complex numbers and transform them into frequency information?

I attempted to do something like ListLinePlot[Abs[Fourier[data]], PlotRange -> All] but it produced a strange looking Plot which was nothing like I was expecting.

Thanks

Aaron

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# Fourier Frequency Identification

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