Converting Joystick voltage to movement.

Hello,

I'm working on a project that controls an Xbox controller from a micro-controller. I am wondering if any of you guys (game programmers) would know if there is some standard function (mathematical function) that they use to convert the potentiometer voltage of the joystick to some velocity in the game. I'm talking about a game like Halo. Converting the voltage to how fast he runs or specifically the angular velocity the gun pointer moves, the courser moves in a circle. I'm pretty sure its some kind of exponential function or logarithmic or some higher order polynomial. I can find out by plotting a tun of points and getting a function of the plot. But I thought maybe there is already a known function for it. I hope my question is clear.


Thanks,
Matt