# XX_Dist

Advanced Analysis Library Only

AnalysisLibErrType XX_Dist (double xx, int degreesOfFreedom, double *probabilityXX);

## Purpose

Approximates the one-sided probability:

p = prob(X xx)

where X is a random variable from the 2-distribution with the specified degrees of freedom

### Example

double x, p;
int n;
x = -123.456;
n = 6;
XX_Dist (x, n, &p);
/* Now p = 0 because chi-square distributed variables are non-negative. */

## Parameters

Input
Name | Type | Description
xx | double-precision | The point from which the probability is computed. Range: –∞ < x < 1420;
degreesOfFreedom | integer | Degrees of freedom for the chi-squared distribution.
Output
Name | Type | Description
probabilityXX | double-precision | Calculated probability (0 p < 1).

## Return Value

Name | Type | Description
status | AnalysisLibErrType | A value that specifies the type of error that occurred. Refer to analysis.h for definitions of these constants.