Plots circular or elliptical orbits, or effect of "Solar Wind" on orbit.
Graph Database file SWIND.85D for the TI-85.




By proper choice of initial conditions and parameter
values, you can plot circular orbits, elliptical orbits,
or consider the effect of a "Solar wind" on an orbit.
Q1 is x, Q'1 is vel_x and also Q2.  Q'2 is acc_x.
Q3 is y, Q'3 is vel_y and also Q4.  Q'4 is acc_y.
On the home screen, set values of M, WINDX and WINDY:
5.98E24 -> M
0 -> WINDX
0 -> WINDY
These parameter values will give a circular orbit.
To show the effect of a solar wind, directed to the North,
try  .2 -> WINDY
To get an elliptical orbit, change initial condition
Q'2 to 8400.