R/qci.R

In musto101/wilcox_R: What the package does (short line)

qci <-
function(x,q=.5,alpha=.05,op=3){
#
# Compute a confidence interval for qth quantile
#  using an  estimate of standard error based on
#  adaptive kernel density estimator.
# The qth quantile is estimated with a single order statistic.
#
# For argument op, see the function qse.
#
if(sum(duplicated(x)>0))stop("Duplicate values detected; use hdpb")
n<-length(x)
xsort<-sort(x)
iq <- floor(q * n + 0.5)
qest<-xsort[iq]
se<-qse(x,q,op=op)
crit<-qnorm(1-alpha/2)
ci.low<-qest-crit*se
ci.up<-qest+crit*se
list(ci.low=ci.low,ci.up=ci.up,q.est=qest)
}