scipy.interpolate.PchipInterpolator.derivatives

PchipInterpolator.derivatives(x, der=None)

Evaluate many derivatives of the polynomial at the point x

Produce an array of all derivative values at the point x.

Parameters :

x : array-like

Point or points at which to evaluate the derivatives

der : None or integer

How many derivatives to extract; None for all potentially nonzero derivatives (that is a number equal to the number of points). This number includes the function value as 0th derivative.

Returns :

d : ndarray

Array with derivatives; d[j] contains the j-th derivative. Shape of d[j] is determined by replacing the interpolation axis in the original array with the shape of x.

Examples

>>> KroghInterpolator([0,0,0],[1,2,3]).derivatives(0)
array([1.0,2.0,3.0])
>>> KroghInterpolator([0,0,0],[1,2,3]).derivatives([0,0])
array([[1.0,1.0],
       [2.0,2.0],
       [3.0,3.0]])