scipy.special.gammainc¶
-
scipy.special.
gammainc
(a, x) = <ufunc 'gammainc'>¶ Regularized lower incomplete gamma function.
Defined as
\[\frac{1}{\Gamma(a)} \int_0^x t^{a - 1}e^{-t} dt\]for \(a > 0\) and \(x \geq 0\). The function satisfies the relation
gammainc(a, x) + gammaincc(a, x) = 1
wheregammaincc
is the regularized upper incomplete gamma function.See also
gammaincc
regularized upper incomplete gamma function
gammaincinv
inverse to
gammainc
versusx
gammainccinv
inverse to
gammaincc
versusx
Notes
The implementation largely follows that of [1].
References
- 1(1,2)
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