7.8 F distribution

R script for F distribution

Df

## function (f, nu1, nu2) 
## {
##     if (nu1 <= 0 | nu2 <= 0) {
##         warning("bad nu1, nu2 for an F distribution")
##         return(NULL)
##     }
##     if (f <= 0) {
##         warning("bad f for an F distribution")
##         return(NULL)
##     }
##     return(exp((0.5 * nu1 - 1) * log(f) - 0.5 * (nu1 + nu2) * 
##         log(nu2 + nu1 * f) + 0.5 * (nu1 * log(nu1) + nu2 * log(nu2)) + 
##         gammln(0.5 * (nu1 + nu2)) - gammln(0.5 * nu1) - gammln(0.5 * 
##         nu2)))
## }
## <bytecode: 0x000001e2a5d020e8>
## <environment: namespace:math>

Pf

## function (f, nu1, nu2) 
## {
##     if (nu1 <= 0 | nu2 <= 0) {
##         warning("bad nu1, nu2 for an F distribution")
##         return(NULL)
##     }
##     if (f <= 0) {
##         warning("bad f for an F distribution")
##         return(NULL)
##     }
##     return(betai(0.5 * nu1, 0.5 * nu2, nu1 * f/(nu2 + nu1 * f)))
## }
## <bytecode: 0x000001e2ac6e95b8>
## <environment: namespace:math>

Qf

## function (p, nu1, nu2) 
## {
##     if (nu1 <= 0 | nu2 <= 0) {
##         warning("bad nu1,nu2 for an F distribution")
##         return(NULL)
##     }
##     if (p <= 0 || p >= 1) {
##         warning("bad p for an F distribution")
##         return(NULL)
##     }
##     x = invbetai(p, 0.5 * nu1, 0.5 * nu2)
##     return(nu2 * x/(nu1 * (1 - x)))
## }
## <bytecode: 0x000001e2ac7c07e8>
## <environment: namespace:math>