Creating vehicle path from radius of curvature

Hi,

Has anyone got a reference or know of a function to help create X and y co-ordinates based on known instantaneous radius and traveled distance?

The data I have is the measured longitudinal travel distance along the path as well as the radius of the path of the vehicle at that point (calculated from known speed and lateral acceleration, v^2/a).

Appreciate if someone could help point me in the right direction.