# Gamma Function (Incomplete Gamma Function) (G Dataflow)

Version:

Evaluates the regularized incomplete gamma function.

## x

The real input of the incomplete gamma function. x must be nonnegative.

Default: 0

## a

The upper limit of the regularized incomplete gamma function.

Default: Positive infinity

## error in

Error conditions that occur before this node runs. The node responds to this input according to standard error behavior.

Default: No error

## g(x, a)

The result of the regularized incomplete gamma function for the given values of x and a.

## error out

Error information. The node produces this output according to standard error behavior.

## Algorithm for Evaluating the Regularized Incomplete Gamma Function

The following equation defines the regularized incomplete gamma function.

$\mathrm{\Gamma }\left(x,a\right)=\frac{1}{\mathrm{\Gamma }\left(x\right)}{\int }_{0}^{a}{t}^{x-1}{e}^{-t}dt$

The following intervals for the input values define the function.

$a\in \left(0,\infty \right),\text{\hspace{0.17em}}x\in \left[0,\infty \right)$

The following illustration shows the regularized incomplete gamma functions with a = 1, 2, 3, and 4 from top to bottom.

Where This Node Can Run:

Desktop OS: Windows

FPGA: Not supported