To run the demo (assuming that your working directory is SCIDIR/demos/wheel2);
1: If necessary, compile the Fortran routines (this is done by the Makefile)
   in SCIDIR/demos/wheel2.
2: run the "ex" file ("exec(ex)") in Scilab (change the values in the first
   line of this file for changing initial conditions (uncomment)).
   exec(sci+'/demos/wheel2/ex')
3. Enter the command "show(x)" in Scilab for plotting the wheel.

Also you can use the macro wheel (file "wheel.sci") to compute x and
plot the results by the macro show (file "wheel_show.sci").

The fortran files (bigmat.f, constr.f, inigrd.f) are automatically
generated by Maple: Invoke Maple and input the command `read roue.ex`:
