[Numpy-discussion] Fit 2D points to closed curve

Hi, I use a CAD package called Rhino which lets users write python scripts that run in the cad environment. I have a closed curve that is a design surface border and I have a sparse data set of 2D surveyed points taken around that border, so some error is included in the 2D data set. I would like to know what python function I could use to do a 2D best fit of the points to the curve. Plenty of examples of fitting curves to points but not of best fitting points to a closed curve of which I do not know the formula. Any help or advice greatly appreciated.