Module « scipy.special »

Fonction rgamma - module scipy.special

Signature de la fonction rgamma

Description

rgamma.__doc__

rgamma(x, /, out=None, *, where=True, casting='same_kind', order='K', dtype=None, subok=True[, signature, extobj])

rgamma(z, out=None)

Reciprocal of the gamma function.

Defined as :math:`1 / \Gamma(z)`, where :math:`\Gamma` is the
gamma function. For more on the gamma function see `gamma`.

Parameters
----------
z : array_like
    Real or complex valued input
out : ndarray, optional
    Optional output array for the function results

Returns
-------
scalar or ndarray
    Function results

Notes
-----
The gamma function has no zeros and has simple poles at
nonpositive integers, so `rgamma` is an entire function with zeros
at the nonpositive integers. See the discussion in [dlmf]_ for
more details.

See Also
--------
gamma, gammaln, loggamma

References
----------
.. [dlmf] Nist, Digital Library of Mathematical functions,
    https://dlmf.nist.gov/5.2#i

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

It is the reciprocal of the gamma function.

>>> sc.rgamma([1, 2, 3, 4])
array([1.        , 1.        , 0.5       , 0.16666667])
>>> 1 / sc.gamma([1, 2, 3, 4])
array([1.        , 1.        , 0.5       , 0.16666667])

It is zero at nonpositive integers.

>>> sc.rgamma([0, -1, -2, -3])
array([0., 0., 0., 0.])

It rapidly underflows to zero along the positive real axis.

>>> sc.rgamma([10, 100, 179])
array([2.75573192e-006, 1.07151029e-156, 0.00000000e+000])