[R] Subsetting to unique values

Emslie, Paul [Ctr] emsliep at atac.mil
Fri Jun 6 15:35:42 CEST 2008


I want to take the first row of each unique ID value from a data frame.
For instance
> ddTable <-
data.frame(Id=c(1,1,2,2),name=c("Paul","Joe","Bob","Larry"))

I want a dataset that is 
Id	Name
1	Paul
2	Bob

> unique(ddTable)
Will give me all 4 rows, and
> unique(ddTable$Id) 
Will give me c(1,2), but not accompanied by the name column.



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