[TribulationStaff]

Most Graalians don't know about vectors, so I figured I would suggest the simplest answer.

For those of you who don't know, a vector is an arbitrary motion through a plane or through a field. Where it starts doesn't matter. all a vector tells you is where you are going. They are often written in the notation <dx,dy>

So the vector <1,3> could move something from (0,0) to (1,3), but it would be the same vector if it moved something from (8,2) to (9,5)

In Kai's solution, you need two vectors. The first moves the player around the circumference of the circle. The second moves the player towards the center of the circle.

[edit] After rereading Kai's post, I see that he is being clever and using a vector that is orthagonal to the first. That dependance upon the pull vector allows for the removal of trigonometry[/edit]