order

order: number

order of polynomial

The order is the number of basis functions that are in effect at any knot value.
The order is the number of points that affect the curve at any knot value, i.e. the size of the "local support" set
order=2 is lines (degree 1)
order=3 is quadratic (degree 2)
order=4 is cubic (degree 3)
The number of knots follows the convention "poles+order= knots".
In this convention (for example), a clamped cubic with knots [0,0,0,0, 1,2,3,4,4,4,4] has:
- 4 (order) copies of the start and end knot (0 and 4) and
- 3 interior knots
Hence expect 7 poles.

Last Updated: 20 June, 2023