Pendula 1.0
                    Copyright (C) 1995 James E. Hetrick


Pendula simulates the coupled pendulum problem, with two equal length
and equal mass rods.

Pendula uses a 4th order Rung-Kutte algorithm to integrate the equations
of motion derived from the Lagrangian of the system. A PostScript
version of this computation should accompany the Pendula package
shortly (look for it where you downloaded this package).

It requires a mouse and EGA or better graphics.

To run Pendula, simply type 

	pendula

Command line options are: 

	pendula [timestep]
	pendula [theta_1] [theta_2]
	pendula [timestep] [theta_1] [theta_2]

where:	
	timestep,  determines the speed of the simulation. Typical
                   speeds are 0.0005 for a 60 Hz 486. The default (for
                   my laptop, where this was written, is 0.025, and is 
		   apt to be far too fast on most modern machines).

	theta_1,  is the angle (in degrees) of the inner rod from the 
		  horizontal, ie. theta_1 = 0 is pointing directly to
		  the right.

	theta_2,  is the the angle of the outer rod, measured from the
		  the inner rod. Thus theta_2 = 0 means the rod is
                  folded, while theta_2 = 180 is fully extended.

The menu bar contains:

File:  (does nothing yet, although the EXIT option works)

Display:
	Clear   -- clears the screen
	Trace 1 -- toggles Trace of the end point of the inner rod
		   Default is OFF
	Trace 2 -- toggles Trace of the end point of the outer rod
		   Default is ON

Configurations:
	Several starting configurations for the rods.

Run:  Run simulation.  *Hitting ANY KEY STOPS the simulation*


Note that moving the mouse during simulation can cause anomolous screen
writes. This is because the simulation part of the program isn't yet
a fully interactive object, which will be remedied soon.

Pendula was written in C++. It is very much in the developmental
phase and your comments are welcome. Please check again soon for a new
version.


J. E. Hetrick					Dec. 1995

  hetrick@physics.arizona.edu
  http://www.physics.arizona.edu/~hetrick

  Dept. of Physics and Astronomy
  University of Arizona
  Tucson, AZ 85721