http://weelookang.blogspot.sg/2013/12/ejss-wave-1d-superposition-model.html

One Dimensional Wave Superposition JS Model

The One-Dimensional Wave Function Superposition JavaScript Model shows how the superposition principle gives rise to wave phenomena such as standing waves and beats.  Users enter real-valued wave functions and observe both the time dependent functions and their superposition. This model uses the JavaScript mathematical function parser.

Credits:

The One Dimensional Wave Function Superposition JavaScript Model was developed by Wolfgang Christian and Francisco Esquembre using version 5 of the Easy Java Simulations (EJS 5) modeling tool.  Although EJS is a Java program, EJS 5 creates stand alone JavaScript programs that run in almost any PC or tablet browser.  Information about EJS is available at: <http://www.um.es/fem/Ejs/> and in the OSP ComPADRE collection <http://www.compadre.org/OSP/>.