I'm not sure what you want, but take a look at ?merge and %in%
ppaarrkk wrote: > > I want to compare two matrices or data frames and select or get an index > for those rows which are the same in both. I have tried the following : > > > > > > > a = matrix ( 1:10, ncol = 2 ) > a > > b = matrix ( c ( 2,3,4,7,8,9 ), ncol = 2 ) > b > > a[a==b] > > > > > > > a = as.data.frame ( matrix ( 1:10, ncol = 2 ) ) > a > > b = as.data.frame ( matrix ( c ( 2,3,4,7,8,9 ), ncol = 2 ) ) > b > > a[a==b] > > > > > > > > > Any ideas please. > > > Thanks. > > > Simon Parker > Imperial College > > -- View this message in context: http://www.nabble.com/Selecting-rows-that-are-the-same-in-separate-data-frames-tp20916243p20916727.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ [email protected] 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.
