[phkahler]

Another fun experiment is to write script to cover a disk with points, then do a full calculation of all N gravitational forces at a point along the radius. Calculate the acceleration of a mass at that point and back-calculate the velocity that would orbit with that inward force. Repeat this for many points along the radius and plot the rotation curve without doing any dynamic simulation. There can be some interesting numerical issues with this but a random set of points to "measure" the curve will still show it.