fcdf

 

Description

computes F cumulative distribution function at dF, with parameters df1 and df2. The parameters of df1 and df2 must all be positive, and the values in dF must lie on the interval [0,1]. It can be the upper tailed or lower tailed.

Syntax

double fcdf( const double dF, double df1, double df2, int iTail = TAILED_TEST_LOWER, int * nFail = NULL )

Parameters

dF
[input] value of the F variate, f. .
df1
[input] degrees of freedom of the numerator variance, , must be positive (df1>0 ).
df2
[input] degrees of freedom of the denominator variance, , must be positive(df2>0).
iTail
[input] upper tailed, or lower tailed test.
1 = TAILED_TEST_UPPER,
2 = TAILED_TEST_LOWER.
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 F-distribution cumulative distribution function

Examples

EX1

void fcdf_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, fcdf(x[ii], df1, df2));
}

Remark

See Also

finv

header to Include

origin.h

Reference