A periodic signal can be described by a Fourier decomposition as a Fourier series, i. e. as a sum of sinusoidal and cosinusoidal oscillations. By reversing this procedure a periodic signal can be generated by superimposing sinusoidal and cosinusoidal waves. The general function is:

The Fourier series of a square wave is

or

The Fourier series of a saw-toothed wave is

The approximation improves as more oscillations are added.

No Java, no applet! Sorry! But it would look like this:

This applet uses the sun.audio package. HotJava users should set Class access to Unrestricted.

The source code (version 96/07/15) is available according to the GNU Public License.

Tom Huber, huber@gac.edu has written an enhanced version.

1. , i. e. x(t) is absolutely integratable,
2. variations of x(t) are limited in every finite time interval T and
3. there is only a finite set of discontinuities in T.

Diese Seite auf Deutsch