Interpolation of points
PROBLEM: Interpolation of points, which are later differentiated to study the curvature
USED COMMANDS/METHODS: I've tried using \MFOURI, \VITRP, and \MOPER commands which generate interpreted data, however, the generated points when differentiated and plotted yield wavy/noisy behaviour (not desired) as the blue curve in the picture. This is because these commands apply different techniques of interpolation.
QUESTION: Are there any commands which use piecewise cubic interpolation with the not-a-knot method?
Any suggestions are heartily appreciated, thanks in advance!