[R] Identifying duplicate rows?

[jim holtman]

try this:

dfA$dups<-duplicated(dfA$Value) | duplicated(dfA$Value, fromLast = TRUE)

On Mon, Sep 10, 2012 at 2:23 PM, kborgmann <borgmann at email.arizona.edu> wrote:
> Hi,
> I am trying to identify duplicate values in a column in a date frame.  The
> duplicated function identifies the duplicate rows in the data frame but it
> only does this for the second record, not both records. Is there a way to
> mark both rows in the data frame as TRUE?
> dfA$dups<-duplicated(dfA$Value)
> dfA
> Site    State Value dups
> 929     VA      73 FALSE
> 929     VA      73  TRUE
> 930     VA      76 FALSE
> 930     VA      76 TRUE
> 931     VA      74 FALSE
> 932     VA      75 FALSE
>
> But I would like this
> Site    State Value dups
> 929     VA      73 TRUE
> 929     VA      73  TRUE
> 930     VA      76 TRUE
> 930     VA      76 TRUE
> 931     VA      74 FALSE
> 932     VA      75 FALSE
>
> Thank you for your replies!
> Still on the learning curve,
> Kathi
>
>
>
> --
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-- 
Jim Holtman
Data Munger Guru

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Tell me what you want to do, not how you want to do it.