KroghInterpolator.derivative(x, der=1)[source]

Evaluate one derivative of the polynomial at the point x


x : array_like

Point or points at which to evaluate the derivatives

der : integer, optional

Which derivative to extract. This number includes the function value as 0th derivative.


d : ndarray

Derivative interpolated at the x-points. Shape of d is determined by replacing the interpolation axis in the original array with the shape of x.


This is computed by evaluating all derivatives up to the desired one (using self.derivatives()) and then discarding the rest.