The Fourier Series is then leveraged, adding spinning vectors for the harmonics to the tip of the last vector. The result of summing these harmonics produces the sine-based square wave ...

If you’re into mechanical devices or Fourier series (or both!), ... [The Engineer Guy] sets some sample points — a square wave — into the machine and it spits out the Fourier coefficients.

Given the data in Excel you can output a Fourier series and then graph it using the XY Scatter graph. Install the Excel Analysis ToolPak. Launch Excel and click on the "File" tab in the upper-left.

An audio waveform theoretically comprised of an infinite set of odd harmonic sine waves. It is often used in sound synthesis. See also: Fourier Theorem, Law of Superposition, Oscillator, Switch.