Testing script/plugin I am writing, ATM it is a plugin, but controlled by a rollout(due to problems with using the plugin as it should be, using a rollout works a lot better)(the output is also a mesh, not a spline, Im using it as a plugin so that I can get results quicker)
Edit:
Changed to a rollout, aswell as changing it so you enter your own expressions for the position of each knot.