Statistical - Cubic Regression (Cubic Spline Fit) ?

[Wes Loewer]

(06-06-2022 01:03 PM)Albert Chan Wrote:  XCAS> T,X,Y := range(5), [0,2,3,4,5], [1,0,3,5,4]
XCAS> tx := spline(T,X) :;
XCAS> ty := spline(T,Y) :;

I think this is how I would have handled it as well. GeoGebra adds a twist by having T be based on the distance between the points instead of the point number. The result is a more intuitive curve when two points are close together.

(06-06-2022 01:03 PM)Albert Chan Wrote:  We could also use complex numbers, combined 2 splines into 1

Very interesting. I'm always fascinated by the use of complex numbers (or even quaternions) in applications that are originally intended for real numbers.