R/Dqdif.R

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

Dqdif <-
function(x,y=NULL,q=.25,nboot=1000,plotit=TRUE,xlab="Group 1 - Group 2",SEED=TRUE,alpha=.05){
#
#  Compare two dependent groups by comparing the
#  q and 1-q quantiles of the difference scores
#
# q should be < .5
# if the groups do not differ, then the difference scores should be symmetric
# about zero.
# In particular, the sum of q and 1-q quantiles should be zero.
#
# q indicates the quantiles to be compared. By default, the .25 and .75 quantiles are used.
#
if(SEED)set.seed(2)
if(q>=.5)stop("q should be less than .5")
if(!is.null(y)){
xy=elimna(cbind(x,y))
dif=xy[,1]-xy[,2]
}
if(is.null(y))dif=elimna(x)
n=length(dif)
if(plotit)akerd(dif,xlab=xlab)
bvec=NA
data<-matrix(sample(n,size=n*nboot,replace=TRUE),nrow=nboot)
for(ib in 1:nboot){
bvec[ib]<-hd(dif[data[ib,]],q=q)+hd(dif[data[ib,]],q=1-q)
}
est1=hd(dif,q=q)
est2=hd(dif,q=1-q)
pv=mean(bvec<0)+.5*mean(bvec==0)
p=2*min(c(pv,1-pv))
low<-round((alpha/2)*nboot)+1
up<-nboot-low
sbvec=sort(bvec)
ci=sbvec[low]
ci[2]=sbvec[up]
list(est.q=est1,est.1.minus.q=est2,conf.interval=ci,p.value=p)
}