The F_CVF function computes the cutoff value *V* in an F distribution with degrees of freedom in the numerator and degrees of freedom in the denominator such that the probability that a random variable *X* is greater than *V* is equal to a user-supplied probability *P*.

This routine is written in the IDL language. Its source code can be found in the file f_cvf.pro in the lib subdirectory of the IDL distribution.

## Examples

Use the following command to compute the cutoff value in an F distribution with ten degrees of freedom in the numerator and six degrees of freedom in the denominator such that the probability that a random variable X is greater than the cutoff value is 0.01. The result should be 7.87413:

PRINT, F_CVF(0.01, 10, 6)

## Syntax

*Result* = F_CVF(*P*,* Dfn*,* Dfd*)

## Return Value

Returns the cutoff value *V*, given a distribution *F*, with specified degrees of freedom in the numerator and denominator.

## Arguments

### P

A non-negative single- or double-precision floating-point scalar, in the interval [0.0, 1.0], that specifies the probability of occurrence or success.

### Dfn

A positive integer, single- or double-precision floating-point scalar that specifies the number of degrees of freedom of the F distribution numerator.

### Dfd

A positive integer, single- or double-precision floating-point scalar that specifies the number of degrees of freedom of the F distribution denominator.

## Keywords

None.

## Version History

4.0 |
Introduced |

## See Also

CHISQR_CVF, F_PDF, GAUSS_CVF, T_CVF