# Beta

Advanced Analysis Library Only

double Beta (double x, double y, double *a);

## Purpose

Computes the beta or incomplete beta function. The beta function is defined as follows:

The beta function relates to the gamma function through the following formula:

The incomplete beta function is defined as follows:

## Parameters

Input
Name | Type | Description
x | double-precision | The input argument of the beta or incomplete beta function. Refer to the definition formula of the beta function for more information about x and y.
y | double-precision | The input argument of the beta or incomplete beta function. Refer to the definition formula of the beta function for more information about x and y.
a | double-precision pointer | The upper limit of the incomplete beta integral. If a is NULL, this function computes the complete beta function.

## Return Value

Name | Type | Description
result | double-precision | The evaluated beta function value.