Pattern formation and KPP equation

Solve KPP equation by finite difference method to generate 2D patterns.

This 15-line matlab program solves the nonlinear reaction
diffusion equation, called Kolmogorov-Petrovskii-Piskunov
(KPP) equation to generate patterns (ribbons and rings).
The numerical method is simple and program is easy to
understand, and it can be extended to simulated
more complex systems. The snapshot was generated by pattern(400);