Hi Ista, When you write a package, you have to anticipate what users will throw at the code. I can insist that users only input matriices where none of the column names are empty, but that's not what I wish to impose on the users. I can add the name if it's empty, but as a user I don't want a function to do that, either. That's why I need to look for a workaround.
Using which() seems rather clumsy for the purpose, as I need to combine those with the non-empty ones, and preserving ordering would be a mess. Andy > -----Original Message----- > From: r-help-boun...@r-project.org > [mailto:r-help-boun...@r-project.org] On Behalf Of Ista Zahn > Sent: Wednesday, February 01, 2012 5:45 AM > To: r-help@r-project.org > Subject: Re: [R] indexing by empty string (was RE: Error in > predict.randomForest ... subscript out of bounds with NULL name in X) > > Hi Andy, > > On Tuesday, January 31, 2012 08:44:13 AM Liaw, Andy wrote: > > I'm not exactly sure if this is a problem with indexing by > name; i.e., is > > the following behavior by design? The problem is that > names or dimnames > > that are empty seem to be treated differently, and one > can't index by them: > > > > R> junk = 1:3 > > R> names(junk) = c("a", "b", "") > > R> junk > > a b > > 1 2 3 > > R> junk[""] > > <NA> > > NA > > R> junk = matrix(1:4, 2, 2) > > R> colnames(junk) = c("a", "") > > R> junk[, ""] > > Error: subscript out of bounds > > You can index them by number, e.g., > junk[, 2] > > and you can use which() to find the numbers where the colname > is empty. > > junk[, which(colnames(junk) == "")] > > > > > > I may need to find workaround... > > Going back to the original issue with predict, I don't think > you need a > workaround. I think you need give your matrix some colnames. > > Best, > Ista > > > > > > -----Original Message----- > > > From: r-help-boun...@r-project.org > > > [mailto:r-help-boun...@r-project.org] On Behalf Of > Czerminski, Ryszard > > > Sent: Wednesday, January 25, 2012 10:39 AM > > > To: r-help@r-project.org > > > Subject: [R] Error in predict.randomForest ... subscript out > > > of bounds with NULL name in X > > > > > > RF trains fine with X, but fails on prediction > > > > > > > library(randomForest) > > > > chirps <- > > > > > > > c(20,16.0,19.8,18.4,17.1,15.5,14.7,17.1,15.4,16.2,15,17.2,16,17,14.1) > > > > > > > temp <- > > > > > > c(88.6,71.6,93.3,84.3,80.6,75.2,69.7,82,69.4,83.3,78.6,82.6,80 > > > .6,83.5,76 > > > .3) > > > > > > > X <- cbind(1,chirps) > > > > rf <- randomForest(X, temp) > > > > yp <- predict(rf, X) > > > > > > Error in predict.randomForest(rf, X) : subscript out of bounds > > > > > > BTW: Just find out that apparently predict() does not like > > > NULL name in > > > > > > X, because this works fine: > > > > one <- rep(1, length(chirps)) > > > > X <- cbind(one,chirps) > > > > rf <- randomForest(X, temp) > > > > yp <- predict(rf, X) > > > > > > Ryszard Czerminski > > > AstraZeneca Pharmaceuticals LP > > > 35 Gatehouse Drive > > > Waltham, MA 02451 > > > USA > > > 781-839-4304 > > > ryszard.czermin...@astrazeneca.com > > > > > > > > > -------------------------------------------------------------- > > > ------------ > > > Confidentiality Notice: This message is private and may > > > ...{{dropped:11}} > > > > > > ______________________________________________ > > > 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. > > > > Notice: This e-mail message, together with any > attachme...{{dropped:11}} > > > > ______________________________________________ > > 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. > Notice: This e-mail message, together with any attachme...{{dropped:11}} ______________________________________________ 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.