mindspore.ops.igamma

mindspore.ops.igamma(input, other)

Calculates lower regularized incomplete Gamma function.

If we define input as a and other as 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.

Above \(Q(a, x)\) is the upper regularized complete Gamma function.

Warning

This is an experimental API that is subject to change or deletion.

Parameters

• input (Tensor) – The first input tensor. With type of float32 or float64.

• other (Tensor) – The second input tensor. With float32 or float64 type. other should have the same dtype with input.

Returns

Tensor, has the same dtype as input and other.

Raises

• TypeError – If input or other is not a Tensor.

• TypeError – If dtype of input other and a is not float32 nor float64.

• TypeError – If other has different dtype with input.

• ValueError – If input could not be broadcast to a tensor with shape of other.

Supported Platforms:

Ascend GPU CPU

Examples

>>> import numpy as np
>>> from mindspore import Tensor, ops
>>> a = Tensor(np.array([2.0, 4.0, 6.0, 8.0]).astype(np.float32))
>>> x = Tensor(np.array([2.0, 3.0, 4.0, 5.0]).astype(np.float32))
>>> output = ops.igamma(a, x)
>>> print(output)
[0.593994 0.35276785 0.21486944 0.13337152]