Spline Command

Spline( <List of Points> ): Creates a cubic spline through all points.
Spline( <List of Points>, <Order ≥ 3> ): Creates a spline with given order through all points.
Spline( <List of Points>, <Order ≥ 3>, <Weight Function> ): Creates a spline with given order through all points. The weight function says what should be the difference of t values for point P_i and P_i+1 given their difference P_i+1 - P_i = (x, y). To get the spline you expect from "function" algorithm you should use abs(x)+0*y, to get the GeoGebra’s default spline you can use sqrt(x^2+y^2).

The choice of default makes the result behave nicely when transformed, making sure that Rotate(Spline(list), a) gives the same as Spline(Rotate(list, a)).