Hi, I guess you are not talking about the melt() method. dat1<-read.table(text=" Year Route Point Sp1 Sp2 Sp3 2004 123 123-1 0 1 0 2004 123 123-2 0 1 1 2004 123 123-10 1 1 0 ",header=TRUE,sep="",stringsAsFactors=FALSE)
#If all the Sp columns are located next to another as shown in your example dataset, then you can also try this: name1<-unlist(strsplit(paste(colnames(dat1)[4:6],collapse=" ")," ")) reshape(dat1,varying=4:6,v.name="Sp-value",times=name1,timevar="Sp-name",idvar=c("Year","Route","Point"),direction="long") A.K. ----- Original Message ----- From: Rui Barradas <ruipbarra...@sapo.pt> To: agoijman <agoij...@cnia.inta.gov.ar> Cc: r-help@r-project.org Sent: Sunday, October 7, 2012 2:32 PM Subject: Re: [R] Presence/ absence data from matrix to single column Hello, I haven't been following this thread but apparently the answer to your worries is no. You can use a combination of names() and grep() to sort it out. something like #nms <- names(adat) nms <- c("Year", "Route", "Point", paste0("Sp", 1:250)) pattern <- "^Sp[[:digit:]]+$" whichCols <- grep(pattern, nms) whichNames <- nms[whichCols] reshape(..., varying = whichCols, times = whichNames, ...) Hope this helps, Rui Barradas Em 07-10-2012 15:35, agoijman escreveu: > The problem with that, is that I just wrote an example of my database, but I > have around 250 species and more than 500 sites. In the approach you show > me, it looks like I have to enter every species name and sites individually, > right? > > > > -- > View this message in context: > http://r.789695.n4.nabble.com/Presence-absence-data-from-matrix-to-single-column-tp4645271p4645331.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > 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. ______________________________________________ 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.