hi there I have a big dataframe with columns such as: ID, time, OS, IP Each row of that dataframe corresponds to one entry. Within that dataframe for some IDs serveral entries (rows) exist. I would like to get rid of those multiple rows (obviously the other attributes will differ for the same ID). Or put different: I only want one single entry (row) for each ID. Could anyone be so kind and help me out on this one? When I use unique, on the ID column, I only recieve the levels (or each unique ID), but I want to keep the other attributes as well... I have tried to use apply(x,2,unique(data$ID)), but this does not work either... Any help is highly appreciated!