Vous êtes un professionnel et vous avez besoin d'une formation ? Programmation Python
Les compléments Voir le programme détaillé

Module « scipy.special »

Fonction gammainc - module scipy.special

Signature de la fonction gammainc

def gammainc(*args, **kwargs) 

Description

help(scipy.special.gammainc)

gammainc(x1, x2, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature])


    gammainc(a, x, out=None)

    Regularized lower incomplete gamma function.

    It is defined as

    .. math::

        P(a, x) = \frac{1}{\Gamma(a)} \int_0^x t^{a - 1}e^{-t} dt

    for :math:`a > 0` and :math:`x \geq 0`. See [dlmf]_ for details.

    Parameters
    ----------
    a : array_like
        Positive parameter
    x : array_like
        Nonnegative argument
    out : ndarray, optional
        Optional output array for the function values

    Returns
    -------
    scalar or ndarray
        Values of the lower incomplete gamma function

    See Also
    --------
    gammaincc : regularized upper incomplete gamma function
    gammaincinv : inverse of the regularized lower incomplete gamma function
    gammainccinv : inverse of the regularized upper incomplete gamma function

    Notes
    -----
    The function satisfies the relation ``gammainc(a, x) +
    gammaincc(a, x) = 1`` where `gammaincc` is the regularized upper
    incomplete gamma function.

    The implementation largely follows that of [boost]_.

    References
    ----------
    .. [dlmf] NIST Digital Library of Mathematical functions
              https://dlmf.nist.gov/8.2#E4
    .. [boost] Maddock et. al., "Incomplete Gamma Functions",
       https://www.boost.org/doc/libs/1_61_0/libs/math/doc/html/math_toolkit/sf_gamma/igamma.html

    Examples
    --------
    >>> import scipy.special as sc

    It is the CDF of the gamma distribution, so it starts at 0 and
    monotonically increases to 1.

    >>> sc.gammainc(0.5, [0, 1, 10, 100])
    array([0.        , 0.84270079, 0.99999226, 1.        ])

    It is equal to one minus the upper incomplete gamma function.

    >>> a, x = 0.5, 0.4
    >>> sc.gammainc(a, x)
    0.6289066304773024
    >>> 1 - sc.gammaincc(a, x)
    0.6289066304773024
    

Vous êtes un professionnel et vous avez besoin d'une formation ? Programmation Python
Les compléments Voir le programme détaillé