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bundles / scipy 1.17.1 / scipy / interpolate / _fitpack_py / splev

function

scipy.interpolate._fitpack_py:splev

source: /scipy/interpolate/_fitpack_py.py :311

Signature

def   splev ( x tck der = 0 ext = 0 )

Summary

Evaluate a B-spline or its derivatives.

Extended Summary

Given the knots and coefficients of a B-spline representation, evaluate the value of the smoothing polynomial and its derivatives. This is a wrapper around the FORTRAN routines splev and splder of FITPACK.

Parameters

x : array_like

An array of points at which to return the value of the smoothed spline or its derivatives. If tck was returned from splprep, then the parameter values, u should be given.

tck : BSpline instance or tuple

If a tuple, then it should be a sequence of length 3 returned by splrep or splprep containing the knots, coefficients, and degree of the spline. (Also see Notes.)

der : int, optional

The order of derivative of the spline to compute (must be less than or equal to k, the degree of the spline).

ext : int, optional

Controls the value returned for elements of x not in the interval defined by the knot sequence.

  • if ext=0, return the extrapolated value.

  • if ext=1, return 0

  • if ext=2, raise a ValueError

  • if ext=3, return the boundary value.

The default value is 0.

Returns

y : ndarray or list of ndarrays

An array of values representing the spline function evaluated at the points in x. If tck was returned from splprep, then this is a list of arrays representing the curve in an N-D space.

Notes

Manipulating the tck-tuples directly is not recommended. In new code, prefer using BSpline objects.

Array API Standard Support

splev is not in-scope for support of Python Array API Standard compatible backends other than NumPy.

See dev-arrayapi for more information.

Examples

Examples are given :ref:`in the tutorial <tutorial-interpolate_splXXX>`. A comparison between `splev`, `splder` and `spalde` to compute the derivatives of a B-spline can be found in the `spalde` examples section.

See also

BSpline
bisplev
bisplrep
spalde
splint
splprep
splrep
sproot

Aliases

  • scipy.interpolate.splev

Referenced by

This package