FPR

This function evaluates the F probability density function.

Function Return Value

FPR — Function value, the value of the probability density function. (Output)

Required Arguments

F — Argument for which the F probability density function is to be evaluated. (Input)

DFN — Numerator degrees of freedom. (Input)
DFN must be positive.

DFD — Denominator degrees of freedom. (Input)
DFD must be positive.

FORTRAN 90 Interface

Generic: FPR (F, DFN, DFD)

Specific: The specific interface names are S_FPR and D_FPR

FORTRAN 77 Interface

Single: FPR (F, DFN, DFD)

Double: The double precision name is DFPR.

Description

The function FPR evaluates the F probability density function, defined as

 

The parameters and , correspond to the arguments DFN and DFD.

Example

In this example, we evaluate the probability function at F = 2.0, DFN = 10.0, DFD = 1.0.

 

USE UMACH_INT

USE FPR_INT

IMPLICIT NONE

INTEGER NOUT

REAL F, DFN, DFD, PR

CALL UMACH(2, NOUT)

F = 2.0

DFN = 10.0

DFD = 1.0

PR = FPR(F, DFN, DFD)

WRITE (NOUT, 99999) F, DFN, DFD, PR

99999 FORMAT (' FPR(', F6.2, ', ', F6.2, ', ', F6.2, ') = ', F6.4)

END

Output

 

FPR( 2.00, 10.00, 1.00) = 0.1052