Trigonometric Fourier Series

With the Christmas study period (apparently some people mistakenly call it a holiday) now fully underway, I've started working my way through Digital Signal Processing: Concepts and Applications. One of the first concepts covered is the trigonometric Fourier series - the fact that any periodic power signal can be decomposed into a series of sine and cosine waves.

To demonstrate this, and brush up on my JavaScript, I put together this example of the trigonometric Fourier series in practice.

Use the Add button to increase the number of coefficients, Update to update the chart with the new coefficient values, Randomise to assign random values to all coefficients (except A0, the DC bias which is reset to 0) and use the Square wave button to set the coefficients to compose a square wave (the more coefficients you add, the closer it gets to looking like a true square wave).

Fundamental frequency (Hz):

n	An	Bn
0
1
2

Add Update Randomise Square wave

Minimum: Maximum: