Module « scipy.signal »

Fonction gauss_spline - module scipy.signal

Signature de la fonction gauss_spline

def gauss_spline(x, n) 

Description

gauss_spline.__doc__

Gaussian approximation to B-spline basis function of order n.

    Parameters
    ----------
    x : array_like
        a knot vector
    n : int
        The order of the spline. Must be non-negative, i.e., n >= 0

    Returns
    -------
    res : ndarray
        B-spline basis function values approximated by a zero-mean Gaussian
        function.

    Notes
    -----
    The B-spline basis function can be approximated well by a zero-mean
    Gaussian function with standard-deviation equal to :math:`\sigma=(n+1)/12`
    for large `n` :

    .. math::  \frac{1}{\sqrt {2\pi\sigma^2}}exp(-\frac{x^2}{2\sigma})

    References
    ----------
    .. [1] Bouma H., Vilanova A., Bescos J.O., ter Haar Romeny B.M., Gerritsen
       F.A. (2007) Fast and Accurate Gaussian Derivatives Based on B-Splines. In:
       Sgallari F., Murli A., Paragios N. (eds) Scale Space and Variational
       Methods in Computer Vision. SSVM 2007. Lecture Notes in Computer
       Science, vol 4485. Springer, Berlin, Heidelberg
    .. [2] http://folk.uio.no/inf3330/scripting/doc/python/SciPy/tutorial/old/node24.html

    Examples
    --------
    We can calculate B-Spline basis functions approximated by a gaussian
    distribution:

    >>> from scipy.signal import gauss_spline, bspline
    >>> knots = np.array([-1.0, 0.0, -1.0])
    >>> gauss_spline(knots, 3)
    array([0.15418033, 0.6909883, 0.15418033])  # may vary

    >>> bspline(knots, 3)
    array([0.16666667, 0.66666667, 0.16666667])  # may vary