compute_basisfuncs

compas.geometry.compute_basisfuncs(degree, knotvector, i, u)

Compute the nonzero basis functions for a given parameter value.

Parameters:

degreeint

Degree of the curve.

knotvectorlist

Knot vector of the curve.

iint

Knot span index.

ufloat

Parameter value.

Returns:

list[float]

Basis functions.

See also

construct_knotvector

knotvector_to_knots_and_mults

knots_and_mults_to_knotvector

find_span

compute_basisfuncsderivs

Notes

In any given knot span, \(\[u_{j}, u_{j+1}\)\) at most degree + 1 of the \(N_{i,degree}\) basis functions are nonzero, namely the functions \(N_{j-degree,degree}, \dots, N_{j,degree}\).

References

The NURBS Book. Chapter 2. Page 56. The NURBS Book. Chapter 2. Page 70. Algorithm A2.2.