gaminv

1 Description
2 Syntax
3 Parameters
4 Return
5 Examples
6 Remark
7 See Also
8 header to Include
9 Reference

Description

Inverse gamma cumulative distribution function

Syntax

double gaminv( const double dP, double a, double b, int * nFail = NULL )

Parameters

dP: [input] double, the probability from the required Gamma distribution. $0 \leq p \leq 1$ .
a: [input] double, the shape parameter a of the gamma distribution, must be positive(a>0).
b: [input] double, the scale parameter b of the gamma distribution , must be positive(b>0).
nFail: [output] on successful exit, it returns the NAG error code NE_NOERROR; if an error or warning has been detected, then it returns the specific error or warning code.

Return

Returns inverse gamma cumulative distribution function for probability, dP

Examples

EX1

void gaminv_ex1()
{
        double x[]= {0.25, 0.5, 0.75};
        double df1 = 3, df2 = 2;
        for(int ii = 0; ii<3; ii++)
                printf("%f     %f      %f:     %f\n", x[ii], df1, df2, gaminv(x[ii], df1, df2));
}