Nice Rui. Here's a version in base R with no apply(). unique(data.frame(V1=pmin(x$Source,x$Target), V2=pmax(x$Source,x$Target)))
On Fri, Aug 20, 2021 at 6:43 PM Rui Barradas <ruipbarra...@sapo.pt> wrote: > Hello, > > This seems elegant to me but it's also the slowest, courtesy sort. > > apply(x, 1, sort) |> t() |> unique() > > > (My tests show that for small inputs Greg's base apply is fastest, with > nrow(x) > 700, Eric's dplyr is fastest) > > > Hope this helps, > > Rui Barradas > > Às 15:13 de 20/08/21, Greg Minshall escreveu: > > Eric, > > > >> x %>% transmute( a=pmin(Source,Target), b=pmax(Source,Target)) %>% > >> unique() %>% rename(Source=a, Target=b) > > > > ah, very nice. i have trouble remembering, e.g., unique(). > > > > fwiw, (hopefully) here's a baser version. > > ---- > > x = data.frame(Source=rep(1:3,4), > Target=c(rep(1,3),rep(2,3),rep(3,3),rep(4,3))) > > > > y <- apply(x, 1, function(y) return (c(A=min(y), B=max(y)))) > > unique(t(y)) > > ---- > > > > cheers, Greg > > > > ______________________________________________ > > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > > 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 -- To UNSUBSCRIBE and more, see 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.
