derivativeSpline
The derivative B-spline of degree p - 1, with control points p·(Pᵢ₊₁ - Pᵢ) / (uᵢ₊ₚ₊₁ - uᵢ₊₁) and the inner knots; null for degree 1, whose derivative is piecewise constant.
The derivative B-spline of degree p - 1, with control points p·(Pᵢ₊₁ - Pᵢ) / (uᵢ₊ₚ₊₁ - uᵢ₊₁) and the inner knots; null for degree 1, whose derivative is piecewise constant.