I wish to count the number of unique values by grouping of a second variable, and then add the count to the existing data.frame as a new ... ... <看更多>

... <看更多>

1.1 Aggrgate Groups only Unique Group and Count · r unique occurrence of numeric groups · How to add count of unique values by group to R data. ... <看更多>

OK 3) I just found out by pure chance: I have to use the R language ... each group into a new object of itself and then calling unique() on ... ... <看更多>