Wdataclean2 <- function (z, d, wt = rep(1,length(z)) )
{
#  version 1, 2001-11. Mai Zhou
#  does this work for doubly censored data too? YES!
#  d=1---uncensor; d=0---right censor; d=2---left censor.
   niceorder<-order(z,-d)
   sortedz<-z[niceorder]
   sortedd<-d[niceorder]
   sortedw<-wt[niceorder]

   n <- length(sortedd)
   y1 <- sortedz[-1] != sortedz[-n]
   y2 <- sortedd[-1] != sortedd[-n]
   y <- y1 | y2
   
   ind <- c(which(y | is.na(y)), n)

   csumw <- cumsum(sortedw) 

   list( value = sortedz[ind], dd = sortedd[ind],
         weight = diff(c(0, csumw[ind])) )
}


DnR <- function(x, d, w) 
{
# data input should be from Wdataclean2()
# should be used only for right censored data. 
posi <- d == 1

uncenx <- x[posi]
uncenw <- w[posi]

allrisk <- rev(cumsum(rev(w)))

uncenR <- allrisk[posi]

list( time = uncenx, n.risk = uncenR, n.event = uncenw )
}