reliability.R

# Fractile estimation from samples – prediction method with t-student distribution, if you dont know parent pop sd
tp <- function(x,n){
	result <- qt(x,n-1) * sqrt(1+(1/n))
	return(result)
 }
 
# Fractile estimation from samples – prediction method with normal distribution, if you do know parent pop sd
 up <- function(x,n){
	result <- qnorm(x) * sqrt(1+(1/n))
	return(result)
 }
 
# Two functions above use prediciton ethod, think I need to use the 'coverage method' that takes in account confidence.
# Not sure how!
kappa <-function(gamma,x,n,skew){
# some funciton I dont know :(
return (0)
}

# Using prediciton moethods functions, with x=0.05 
# This does not give values in AS/NZS table B1
 kt <- function(n,x,COV){
	k = c(tp(x,n), up(x,n))
	result <- 1/(1 + k*COV)
	return(result)
 }