jax.scipy.special.gammainc

jax.scipy.special.gammainc(a, x)[source]

Regularized lower incomplete gamma function.

LAX-backend implementation of gammainc().

Original docstring below.

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.

Parameters
  • a (array_like) – Positive parameter

  • x (array_like) – Nonnegative argument

Returns

Values of the lower incomplete gamma function

Return type

scalar or ndarray

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