#######################################################################
### This code cleans the right censored data: remove the tie and 
### generates the weight (duplicate index). It do not treat a tied 
### censored obs. and an uncensored obs. as tie.
### In the future it should improve to take the input wt.(instead of all 1)
#######################################################################
"dataclean"<-function(z, d, wt = rep(1, length(z)) ) {
    z0 <- sort(z[d==0])
    if(length(z0) > 1) {
    z0.int<-match(z0,unique(z0))
    z0ends<-c(diff(z0.int) !=0, T)
    wz0 <- diff(c(0,seq(along = z0)[z0ends]))
    newz0<-z0[z0ends]
    } else { newz0 <- z0; wz0 <- wt[d==0] }

    z1 <- sort(z[d==1])
    if(length(z1) > 1) { 
    z1.int<-match(z1,unique(z1))
    z1ends<-c(diff(z1.int) !=0, T)
    wz1 <- diff(c(0,seq(along = z1)[z1ends]))
    newz1<-z1[z1ends]
    } else { newz1 <- z1; wz1 <- wt[d==1] }

    newz <- c(newz0, newz1)
    newd <- c(rep(0, length(newz0) ),rep(1, length(newz1)))
    neww <- c(wz0, wz1)

##    neworder <- order(newz, -newd)   ##do I really need to order them?
##    newz <- newz[neworder]           ##may be not.
##    newd <- newd[neworder]
##    neww <- neww[neworder]
    list(z = newz, d = newd, w = neww)
}