R/med2g.R

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

med2g <-
function(x,y,alpha=.05,nboot=1000,SEED=TRUE,...){
#
#   Compare medians of two independent groups using percentile bootstrap
#
#   Missing values are allowed.
#
x<-elimna(x)
y<-elimna(y)
mvec<-NA
mvec[1]<-median(x)
mvec[2]<-median(y)
bvec<-NA
if(SEED)set.seed(2) # set seed of random number generator so that
#             results can be duplicated.
datax<-matrix(sample(x,size=length(x)*nboot,replace=TRUE),nrow=nboot)
datay<-matrix(sample(y,size=length(x)*nboot,replace=TRUE),nrow=nboot)
bvec1<-apply(datax,1,median) # Bootstrapped values for jth group
bvec2<-apply(datay,1,median) # Bootstrapped values for jth group
test<-sum((bvec1>bvec2))/nboot
tv<-sum(bvec1==bvec2)/nboot
test<-test+.5*tv
if(test> .5)test<-1-test
test<-2*test
dvec<-sort(bvec1-bvec2)
icl<-round(alpha*nboot/2)+1
icu<-nboot-icl-1
cilow<-dvec[icl]
ciup<-dvec[icu]
list(p.value=test,est.1=mvec[1],est.2=mvec[2],est.dif=mvec[1]-mvec[2],ci.low=cilow,ci.up=ciup)
}