RE: [R] extract rows in dataframe with duplicated column values

From: Liaw, Andy <andy_liaw_at_merck.com>
Date: Fri 18 Mar 2005 - 14:14:32 EST


Does this work for you?

> x[table(x[,1]) > 1,]
  a b
2 2 10
3 2 10
5 3 10
6 3 10

Andy

> From: Tiago R Magalhaes
>
> Hi
>
> I want to extract all the rows in a data frame that have duplicates
> for a given column.
> I would expect this question to come up pretty often but I have
> researched the archives and surprisingly couldn't find anything.
> The best I can come up with is:
>
> x <- data.frame(a=c(1,2,2,3,3,3), b=10)
> xdup1 <- duplicated(x[,1])
> xdup2 <- duplicated(x[,1][nrow(x):1])[nrow(x):1]
> xAllDups <- x[(xdup1+xdup2)!=0,]
>
> This seems to work, but it's so convoluted that I'm sure there's a
> better method.
> Thanks for any help and enlightenment
> [[alternative HTML version deleted]]
>
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https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html Received on Fri Mar 18 14:19:27 2005

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