B3

class splinebox.basis_functions.B3

Basis spline of degree 3.

\[\begin{split}f(x) = \begin{cases} \frac{2}{3} - \lvert x \rvert^2 + \frac{\lvert x \rvert^3}{2} & \text{for } 0 \leq \lvert x \rvert < 1 \\ \frac{1}{6}(2 - \lvert x \rvert)^3 & \text{for } 1 \leq \lvert x \rvert \leq 2 \\ 0 & \text{otherwise}\end{cases}\end{split}\]

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