siegel.tukey <- function(x,y,id.col=FALSE,adjust.median=F,rnd=-1,alternative="two.sided",mu=0,paired=FALSE,exact=FALSE,correct=TRUE,conf.int=FALSE,conf.level=0.95)
{
	 if(id.col==FALSE){
	   data=data.frame(c(x,y),rep(c(1,2),c(length(x),length(y))))
	   } else {
		data=data.frame(x,y)
	   }
	 names(data)=c("x","y")
	 data=data[order(data$x),]
	 if(rnd>-1){data$x=round(data$x,rnd)}

	 if(adjust.median==T){
		data$x[data$y==1]=data$x[data$y==1]-(median(data$x[data$y==1])-median(data$x[data$y==2]))/2
		data$x[data$y==2]=data$x[data$y==2]-(median(data$x[data$y==2])-median(data$x[data$y==1]))/2
	 }
	 cat("Median of group 1 = ",median(data$x[data$y==1]),"\n")
	 cat("Median of group 2 = ",median(data$x[data$y==2]),"\n","\n")
	 cat("Test of median differences","\n")
	 print(wilcox.test(data$x[data$y==1],data$x[data$y==2]))

	 a=rep(seq(ceiling(length(data$x)/4)),each=2)
	 b=rep(c(0,1),ceiling(length(data$x)/4))
	 rk.up=c(1,(a*4+b))[1:ceiling(length(data$x)/2)]
	 rk.down=rev(c(a*4+b-2)[1:floor(length(data$x)/2)])

	 cat("Performing Siegel-Tukey rank transformation...","\n","\n")

	 rks=c(rk.up,rk.down)
	 unqs=unique(sort(data$x))
	 corr.rks=tapply(rks,data$x,mean)
	 cbind(unqs,corr.rks)
	 rks.data=data.frame(unqs,corr.rks)
	 names(rks.data)=c("unique values of x","tie-adjusted Siegel-Tukey rank")
	 print(rks.data,row.names=F)
	 names(rks.data)=c("unqs","corr.rks")
	 data=merge(data,rks.data,by.x="x",by.y="unqs")

	 rk1=data$corr.rks[data$y==1]
	 rk2=data$corr.rks[data$y==2]
	 cat("\n","Tie-adjusted Siegel-Tukey ranks of group 1","\n")
	 group1=data.frame(data$x[data$y==1],rk1)
	 names(group1)=c("x","rank")
	 print(group1,row.names=F)
	 cat("\n","Tie-adjusted Siegel-Tukey ranks of group 2","\n")
	 group2=data.frame(data$x[data$y==2],rk2)
	 names(group2)=c("x","rank")
	 print(group2,row.names=F)
	 cat("\n")

	 cat("Siegel-Tukey test","\n")
	 cat("Siegel-Tukey rank transformation performed.","Tie adjusted ranks computed.","\n")
	 if(adjust.median==T) {cat("Medians adjusted to equality.","\n")} else {cat("Medians not adjusted.","\n")}
	 cat("Rank sum of group 1 =", sum(rk1),"    Rank sum of group 2 =",sum(rk2),"\n")


	 res<-wilcox.test(rk1,rk2,alternative=alternative,mu=mu,paired=paired,exact=exact,correct=correct,conf.int=conf.int,conf.level=conf.level)
	 res
}