Thanks for the reply, however, when I do the following command, I receive the message: 'data frame with 0 columns and 0 rows'. I've checked again though, and there should be several thousand rows where the Latitude and Longitude pairs are the same.
> common <- intersect(data_frame_x[c("Latitude", "Longitude")], > data_frame_y[c("Latitude","Longitude")]) > common data frame with 0 columns and 0 rows Is there an obvious solution to this? Should I be using 'unique' instead, and if so, how would I get the above to correspond to this command? Thanks, Steve ________________________________ > Date: Tue, 28 Apr 2009 13:36:51 +0530 > Subject: Re: [R] Finding rows common to two datasets > From: umesh.sriniva...@gmail.com > To: smurray...@hotmail.com > CC: r-help@r-project.org > > Dear Steve, > > Try > > ? intersect > > and see if that might help. > > Cheers, > Umesh > > On Tue, Apr 28, 2009 at 1:29 PM, Steve Murray> wrote: > > > > Dear all, > > > > I have 2 data frames, both with 14 columns of data and differing numbers of > rows. The first two columns are 'Latitude' and 'Longitude'. I want to find > the pairs of Latitude and Longitude coordinates which are common to both > datasets, and output a new data frame which is composed of these coincident > rows. I tried using the 'unique' command, but had difficulties interpreting > the help file. > > > > > Many thanks for any help offered, > > > > Steve > > > > ______________________________________________ > > R-help@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. > > ______________________________________________ R-help@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.