mars.tensor.special.gammaln#

mars.tensor.special.gammaln(x, out=None, where=None, **kwargs)[source]#

Logarithm of the absolute value of the Gamma function.

Parameters

  • x (array-like) – Values on the real line at which to compute gammaln

  • out (Tensor, None, or tuple of Tensor and None, optional) – A location into which the result is stored. If provided, it must have a shape that the inputs broadcast to. If not provided or None, a freshly-allocated tensor is returned. A tuple (possible only as a keyword argument) must have length equal to the number of outputs.

  • where (array_like, optional) – Values of True indicate to calculate the ufunc at that position, values of False indicate to leave the value in the output alone.

  • **kwargs –

Returns

gammaln – Values of gammaln at x.

Return type

Tensor

See also

gammasgn

sign of the gamma function

loggamma

principal branch of the logarithm of the gamma function

Notes

When used in conjunction with gammasgn, this function is useful for working in logspace on the real axis without having to deal with complex numbers, via the relation exp(gammaln(x)) = gammasgn(x)*gamma(x).

For complex-valued log-gamma, use loggamma instead of gammaln.