interpax.CubicSpline.derivative

CubicSpline.derivative(nu: int = 1) → PPolySource

Construct a new piecewise polynomial representing the derivative.

Parameters:

nu (int, optional) – Order of derivative to evaluate. Default is 1, i.e., compute the first derivative. If negative, the antiderivative is returned.

Returns:

pp (PPoly) – Piecewise polynomial of order k2 = k - n representing the derivative of this polynomial.

Notes

Derivatives are evaluated piecewise for each polynomial segment, even if the polynomial is not differentiable at the breakpoints. The polynomial intervals are considered half-open, [a, b), except for the last interval which is closed [a, b].