

INSTRUCTIONS  for Random Walk Applet


To work with this applet, you will need to have a java compiler
on your computer.  If you have a Linux or Mac OS X system, you 
have this already.  If you have a Windows system, you can download
a free Java development system from Sun: http://java.sun.com/ .


If you are equipped with Java, you can run the program by carrying
out the following steps:

 1. Type   javac randomwalk.java  .  This will compile the program.
 2. Type   appletviewer randomwalk.html   or access randomwalk.html
          with your web browser. This will launch the program.
 3. When you launch the program and click the button "Walk", walkers
          will begin to walk in two dimensions.  At the end of the walk, 
          a histogram of the x positions (with bin size = 1) will be 
          displayed in the right-hand box.

Now you can modify the program.  I hope that it will be self-explanatory
  to modify  randomwalk.java.  DO NOT TOUCH randomwalkGUI.java.

randomwalk.java contains three subroutines used by the main program: 
 
    solve()  is the function actually called by the "Walk" button.
        Modify this to adjust the number of walkers and the number
         of steps in the walk.

    step() is the stepping algorithm.  The program is set up to 
        carry out random walks on a 2-d square lattice.  You can 
          modify this to answer the questions in Sethna's problem.

    plotfunction(x) is a function that will be plotted in the right-
       hand box along with the histogram.  Please note that the 
        function given is not quite the correct one.  Can you fix it? 
   