MATLAB code to demonstrate [Fourier series][1] representation of periodic signals (as a sum of sinusoidal functions).

The animation shows an approximation of a square wave signal using the first 4-terms of its Fourier series. (Change the parameters near the top of the code to manipulate the animations and explore other variations).

![animation1][6] ![animation2][7]

This was inspired by the following similar animations:

• [Fourier Series Animation using Circles][2]