Module « scipy.interpolate »

Fonction splev - module scipy.interpolate

Signature de la fonction splev

def splev(x, tck, der=0, ext=0) 

Description

splev.__doc__

    Evaluate a B-spline or its derivatives.

    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 : 3-tuple or a BSpline object
        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.

    See Also
    --------
    splprep, splrep, sproot, spalde, splint
    bisplrep, bisplev
    BSpline

    References
    ----------
    .. [1] C. de Boor, "On calculating with b-splines", J. Approximation
        Theory, 6, p.50-62, 1972.
    .. [2] M. G. Cox, "The numerical evaluation of b-splines", J. Inst. Maths
        Applics, 10, p.134-149, 1972.
    .. [3] P. Dierckx, "Curve and surface fitting with splines", Monographs
        on Numerical Analysis, Oxford University Press, 1993.

    Examples
    --------
    Examples are given :ref:`in the tutorial <tutorial-interpolate_splXXX>`.