Hi r-help-boun...@r-project.org napsal dne 10.02.2009 13:57:44:
> G'day David, > > On Tue, 10 Feb 2009 13:23:50 +0100 > David Croll <david.cr...@gmx.ch> wrote: > > > Well, I knew that attach() only creates a copy of the variables in > > the search path. > > > > What I wanted to ask was how to *retrieve* that copy... > > > > > mat > > id age > > 1 NA NA > > 2 NA NA > > 3 NA NA > > 4 NA NA > > 5 NA NA > > > > > attach(mat) > > > > > id <<- sample(100,5) > > > age <<- rnorm(5,mean=30) > > > > How can I make a new data frame out of the id and age that were > > changed above? > > R> new.df <- data.frame(id,age) > > Or, perhaps more automatic: > > R> new.df <- do.call(data.frame, sapply(ls(pos=2), as.name)) > > Is this what you are after? The question is why he wants to do this? I do not see the point of attaching data frame, changing something in attached frame and then keeping a new copy. Why not mat new.mat <- mat new.mat[,n1] <- some change new.mat[,n2] <- some other change without tricky use of attach if he wants to keep the changed copy. Regards Petr > > Cheers, > > Berwin > > =========================== Full address ============================= > Berwin A Turlach Tel.: +65 6516 4416 (secr) > Dept of Statistics and Applied Probability +65 6516 6650 (self) > Faculty of Science FAX : +65 6872 3919 > National University of Singapore > 6 Science Drive 2, Blk S16, Level 7 e-mail: sta...@nus.edu.sg > Singapore 117546 http://www.stat.nus.edu.sg/~statba > > ______________________________________________ > 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.
