On Mar 26, 2011, at 2:03 PM, Quan Zhou wrote: > Hi > How can I return the index of sort, when I use R function sort? > or any other sorting functions in R > For example, I sorted a vector, but R just return the sorted value > without > giving me the original index of these data. You seem to be looking for: ?order -- David Winsemius, MD West Hartford, CT