Try this: x2 <- merge(x, cbind(unique(x), Site=sprintf("S%d", seq_len(nrow(unique(x))))), by=c("X", "Y")) x2[order(x2$site)]
On 11/02/2008, Weidong Gu <[EMAIL PROTECTED]> wrote: > HI, > > > > I am working on a data set with multiple collections of mosquitoes at > sampling sites. Each row represents a collection of individual samples > with coordinates for each collection. > > ... X, Y,... > > 1 36.435 30.118 > > 2 36.435 30.118 > > 3 36.435 30.118 > > 4 35.329 29.657 > > 5 35.329 29.657 > > 6 36.431 30.111 > > 7 36.431 30.111 > > 8 35.421 29.797 > > 9 35.421 29.797 > > 10 35.421 29.797 > > > > Unfortunately, there is no 'site' entry. I would like to add a column of > 'site' based on the coordinates of samples so that samples from the same > sites have the same site ID like S1, S2,.... > > > > How to do this in R way? Thanks. > > > > > > Weidong Gu, > > Department of Medicine > University of Alabama, Birmingham > 1900 University Blvd., Birmingham, Alabama 35294 > Email: [EMAIL PROTECTED] > PH: (205)-975-9053 > > > > > [[alternative HTML version deleted]] > > ______________________________________________ > 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. > -- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O ______________________________________________ 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.