Program: Euler’s Method
By: Ben Axelrod


    This program will graph an initial value ordinary differential equation 
(ODE) using Euler’s method.  To use, just enter the right hand side of the 
DE that you have at the prompt.  Remember to enter the Y’s and T’s as they 
are.  Then, enter the initial value you have.  Next, enter the window range 
that you want to graph the function.  Keep in mind that the A value for the 
window range must be the same as the T value of your initial value.  

    Example: if your initial value is Y(1)=34, then you must enter 1 for 
the starting A value of the window.  You CAN NOT enter anything else as the 
A value.  The graph you get will be wrong.    

    Finally, enter the number of points the program should use to compute 
the graph.  The more points you enter, the more accurate your graph, but 
the slower the program will run.  Depending on the interval you chose, 50 
to 100 should be OK for a quick graph.  The graph of the function uses 
lists to store data points.  These lists cannot exceed 999 entries.  So DO 
NOT enter more than 999 points.  The other program included is a fix 
program that clears the lists and string created by this program.  That way 
you won’t run out of memory.

      Now the program will display “THINKING…”  It is thinking, be patient. 
The numbers you see in the upper left corner of the screen, is the percent 
done.  That way you can track its progress.  Finally, when it is done 
thinking, you can see the graph.  


Questions or comments, email me at:  bmaxelro@syr.edu