Try this:

DF[!duplicated(DF[,c("lat","lon")]),]


On Mon, Jun 29, 2009 at 6:55 PM, Mark Na <mtb954@gmail.com> wrote:

> Dear R-helpers,
>
> I know how to use unique to select unique rows, e.g.
>
> unique.rows<-unique(dataframe)
>
> but I would like to select those rows that are unique only only TWO of my
> dataframe's columns (so, two rows with the same value on these two columns
> would not be kept, even if they had different values in other columns).
>
> For example, I have a dataframe with 10 columns, two of which are LATITUDE
> and LONGITUDE. I wish to keep only one row per unique combination of these
> two columns, so I've tried:
>
>
> unique.latlong<-extracted[unique(paste(extracted$latitude,extracted$longitude)),]
>
> but this is returning a dataframe of missing values (NAs).
>
> Could anyone point me in the right direction?
>
> Thanks! Mark Na
>
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>
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> PLEASE do read the posting guide
> http://www.R-project.org/posting-guide.html<http://www.r-project.org/posting-guide.html>
> and provide commented, minimal, self-contained, reproducible code.
>



-- 
Henrique Dallazuanna
Curitiba-Paraná-Brasil
25° 25' 40" S 49° 16' 22" O

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