[R] Removing rows in dataframe w'o duplicated values

[Dimitris Rizopoulos]

one approach is the following:

dat <- data.frame(id = c(1,1,1,2,3,3), value = c(5,6,7,4,5,4),
     value2 = c(1,4,3,3,4,3))

ind <- ave(dat$id, dat$id, FUN = length) > 1
dat[ind, ]


I hope it helps.

Best,
Dimitris


On 11/22/2011 6:43 PM, AC Del Re wrote:
> Hi,
>
> Is there an easy way to remove dataframe rows without duplicated values of
> a specified column ('id')?  e.g.,
>
> dat<- data.frame(id = c(1,1,1,2,3,3), value = c(5,6,7,4,5,4), value2 =
> c(1,4,3,3,4,3))
> dat
>
>    id value value2
> 1  1     5      1
> 2  1     6      4
> 3  1     7      3
> 4  2     4      3
> 5  3     5      4
> 6  3     4      3
>
>
> This is sample data and the real data has hundreds of rows. In this
> case, only row 4 does not have a duplicated id and I would like to
> remove it without using:
>
>
> dat$id[4]<- NULL
>
>
> Any help is appreciated!
>
>
> AC
>
> 	[[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.
>

-- 
Dimitris Rizopoulos
Assistant Professor
Department of Biostatistics
Erasmus University Medical Center

Address: PO Box 2040, 3000 CA Rotterdam, the Netherlands
Tel: +31/(0)10/7043478
Fax: +31/(0)10/7043014
Web: http://www.erasmusmc.nl/biostatistiek/