Re: [R] Subsetting to unique values

From: Adrian Dusa <dusa.adrian_at_gmail.com>
Date: Fri, 06 Jun 2008 14:38:50 +0000 (UTC)

Emslie, Paul [Ctr] <emsliep <at> atac.mil> writes:

>
> 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.

ddTable[-which(duplicated(ddTable$Id)), ]

HTH,
Adrian



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