If so, it is not possible to perform an exact conversion between the two formats. It is, however, possible to convert the curve descriptions to the degree of accuracy required. That is, you can reduce any error in the translation to an arbitrarily small tolerance. The paragraphs that follow sketch out a method for converting between these two formats. Subdivide each curve at its inflection points.
Inflection point are locations at which the curvature changes direction.
Parabolic curves cannot have inflection points, hence curves with inflection points cannot be successfully approximated using quadratic splines. This is not a problem, however, as such curves can be subdivided at their inflection points. Fit to a selected tolerance. The method for accomplishing this is to approximate the curve with a single parabola, measure the error, compare that error with the tolerance. If the error is within the tolerance, the fitting is successful.