duplicated_random.R

duplicated.random = function(x, incomparables = FALSE, ...)
{
  if ( is.vector(x) )
  {
    permutation = sample(length(x))
    x.perm      = x[permutation]
    result.perm = duplicated(x.perm, incomparables, ...)
    result      = result.perm[order(permutation)]
    return(result)
  }
  else if ( is.matrix(x) )
  {
    permutation = sample(nrow(x))
    x.perm      = x[permutation,]
    result.perm = duplicated(x.perm, incomparables, ...)
    result      = result.perm[order(permutation)]
    return(result)
  }
  else
  {
    stop(paste("duplicated.random() only supports vectors",
               "matrices for now."))
  }
}