Wdataclean2 <- function (z, d, wt = rep(1,length(z)) ) 
{  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])) )
}
##############################################################
# this function sorts the data, and collaps them
# if there are true tie. and number of tie counted in weight
##############################################################