II.4  Program to Simulate Percolation.
(Value 1.5 quiz grades due Thursday November 3)

Write a program to simulate percolation similar to the program shown in the java applet (except you don't need to create the result display) http://www.physics.buffalo.edu/gonsalves/ComPhys_1998/Java/Percolation.html. Your program should allow you to vary the extent of reaction p, the density of site populated by reacting species r, and the system size N.  The program should test a set number of trials and return the percent of these trials where percolation occured.  You should test for percolation by considering if each point on a side leads to the other size (do both from the top down and from left to right so for a 10 x 10 matrix 20 tests must be made to check for percolation.)  Plot p_c, the percolation threshold for variable density of reacting species and system size.  Comment on your results.