mars.tensor.special.gammainc#
- mars.tensor.special.gammainc(a, b, **kwargs)[源代码]#
Regularized lower incomplete gamma function.
It is defined as
\[P(a, x) = \frac{1}{\Gamma(a)} \int_0^x t^{a - 1}e^{-t} dt\]for \(a > 0\) and \(x \geq 0\). See [dlmf] for details.
- 参数
a (array_like) – Positive parameter
x (array_like) – Nonnegative argument
- 返回
Values of the lower incomplete gamma function
- 返回类型
scalar or ndarray
提示
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].
参见
gammaincc
regularized upper incomplete gamma function
gammaincinv
inverse of the regularized lower incomplete gamma function with respect to x
gammainccinv
inverse of the regularized upper incomplete gamma function with respect to x
引用
- 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