/TensorFlow 1.15

# tf.math.igamma

Compute the lower regularized incomplete Gamma function P(a, x).

The lower regularized incomplete Gamma function is defined as:

$$P(a, x) = gamma(a, x) / Gamma(a) = 1 - Q(a, x)$$

where

$$gamma(a, x) = \\int_{0}^{x} t^{a-1} exp(-t) dt$$

is the lower incomplete Gamma function.

Note, above Q(a, x) (Igammac) is the upper regularized complete Gamma function.

Args
a A Tensor. Must be one of the following types: float32, float64.
x A Tensor. Must have the same type as a.
name A name for the operation (optional).
Returns
A Tensor. Has the same type as a.