tf.igamma()

tf.igamma(a, x, name=None)

Compute the lower regularized incomplete Gamma function Q(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.