Java Applet for Phase Plane

The PRINT option is currently disabled

Note: The parser recognizes all of the standard math functions defined in java.lang.Math. The symbols "E" and "PI" are recognized as java's Math.E and Math.PI.
The parser was written by Darius Bacon and is available at his web site. Please see his file on copying the software.

The java source for the rest of the applet lives in the three files:,, and Please do not use it as an example of good java code.

The package uses a 4th order Runge-Kutta solver with a constant width mesh of 400 points, 200 from t = 0 to t = tmax and 200 from t = 0 to t = tmin. With this rather crude method it is easy to generate equations for which the solver fails badly (try x' = x^3). (As an aside, I have noticed that it is very easy to convert the code in Numerical Recipies in C into java code. A much better solver would be easy to write.)

Copyright © 1997 by Scott A. Herod. All rights reserved.
Last updated by Scott Herod on January 27, 1997.
(Copied to Rutgers by permission.)

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