Dear Michael, Is this what you are looking for?
ex.dat$rn=as.numeric(rownames(ex.dat)) ex.dat # Are new3 and ex.dat equals? all.equal(new3,ex.dat) [1] TRUE HTH, Jorge On Tue, Jul 8, 2008 at 10:58 PM, Michael Rennie <[EMAIL PROTECTED]> wrote: > Hi there, > > I'm sure there's an easy answer to this, and I can't wait to see it. > > The question: is there an easy way to sort a data frame by it's row names? > > My dilemma: > > I've had to pull apart a data frame, run it through a loop to do some > calculations and generate new variables, and then re-construct the chunks > back into a data frame at the end. > > Doing this preserves the row names from the original data frame (which are > informative), so i thought this would make it easy to bring it back to it's > original order. > > However, to do this, I've had to include the row names as a column, and > then > sort by that at the end, which seems terribly redundant and makes me think > there's an easier way to do this. > > See some example code below: > > ########################### > #build a dataframe > > set.seed(12345) > a<-sample(1:50, 15) > b<-15:1 > c<-rep(1:3, 5) > > ex.dat<-data.frame(a,b,c) > > #pull it apart; in my case, each chunk is going through a loop and being > spit out in a list > > sub3<-subset(ex.dat, c=="3") > sub2<-subset(ex.dat, c=="2") > sub1<-subset(ex.dat, c=="1") > > #put it back together; in my case, pull out the parts of the list generated > by the loop that hold the data > > newdat<-rbind(sub3, sub2, sub1) > > #rebuild it such that it can be re-organized into it's original order > > rn<-as.numeric(row.names(newdat)) > > new2<-data.frame(newdat, rn) > > new3 = new2[do.call(order, new2["rn"]), ] > > ###################### > > It's those last three lines of code that I'm sure are unnecessary; why > include a column of information for something that's already there? > However, > most of the posted solutions to sorting of data frames have to do with > sorting by particular variables, not by the row names (which are just > typically 1:n, and is rarely informative). So, this is the solution I came > up with based on what I can find out there currently. > > Looking forward to any thoughts or suggestions. > > -- > Michael D. Rennie > Ph.D. Candidate > University of Toronto at Mississauga > 3359 Missisagua Rd. N. > Mississauga, ON L5L 1C6 > Ph: 905-828-5452 Fax: 905-828-3792 > www.utm.utoronto.ca/~w3rennie <http://www.utm.utoronto.ca/%7Ew3rennie> > > [[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. > [[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.
