MATLAB: Polynomial function 3D

polyfit

Hello,
I would like to put a second order polynomial function through 9 points. The points are given in the form P(x,y,z).
Goal:
(1) Calculate polynomial function
(2) Calculate the mean curvature (= second derivative) of the function
Is there something similar to "p = polyfit(x,y,z,n)"?
Remark:
I can put a circle through three points in space and calculate the corresponding curvature of the circle. For this I use "circlefit3d(p1,p2,p3)". But I don't want to use only 3 of the 9 points for the curvature calculation.
I would be very pleased about a feedback.

Best Answer

You have the file exchange contribution polyfitn that should do what you want.
HTH