SciPy

scipy.interpolate.pchip_interpolate

scipy.interpolate.pchip_interpolate(xi, yi, x, der=0, axis=0)[source]

Convenience function for pchip interpolation. xi and yi are arrays of values used to approximate some function f, with yi = f(xi). The interpolant uses monotonic cubic splines to find the value of new points x and the derivatives there.

See PchipInterpolator for details.

Parameters:
xi : array_like

A sorted list of x-coordinates, of length N.

yi : array_like

A 1-D array of real values. yi’s length along the interpolation axis must be equal to the length of xi. If N-D array, use axis parameter to select correct axis.

x : scalar or array_like

Of length M.

der : int or list, optional

Derivatives to extract. The 0-th derivative can be included to return the function value.

axis : int, optional

Axis in the yi array corresponding to the x-coordinate values.

Returns:
y : scalar or array_like

The result, of length R or length M or M by R,