I'm confusing myself :-) randomForest cannot handle character vectors as predictors. (Which is why I, to my surprise, found out that a categorical variable could not be used in the function). It can handle categorical variables as predictors IF they are put in as a factor.
Obviously they handle categorical variables as a response variable. I hope I'm not going to add up more mistakes, it's been enough for the day... Cheers Joris On Thu, May 27, 2010 at 2:08 PM, <steve_fried...@nps.gov> wrote: > Joris, > > I've been following this thread for a few days as I am beginning to use > randomForest in my work. I am confused by your last email. > > What do you mean that randomForest does not handle categorical variables ? > > It can be used in either regression or classification analysis. Do you > mean that categorical predictors are not suitable? Certainly they are as > the response. > Would you be so kind, and clarify what you were suggesting. > > Thanks, > > Steve Friedman Ph. D. > Spatial Statistical Analyst > Everglades and Dry Tortugas National Park > 950 N Krome Ave (3rd Floor) > Homestead, Florida 33034 > > steve_fried...@nps.gov > Office (305) 224 - 4282 > Fax (305) 224 - 4147 > > > > Joris Meys > <jorism...@gmail. > com> To > Sent by: abanero <gdevi...@xtel.it> > r-help-boun...@r- cc > project.org r-help@r-project.org > Subject > Re: [R] cluster analysis and > 05/27/2010 07:56 supervised classification: an > AM alternative to knn1? > > > > > > > > > > > Hi Abanero, > > first, I have to correct myself. Knn1 is a supervised learning algorithm, > so > my comment wasn't completely correct. In any case, if you want to do a > clustering prior to a supervised classification, the function daisy() can > handle any kind of variable. The resulting distance matrix can be used with > a number of different methods. > > And you're right, randomForest doesn't handle categorical variables either. > So I haven't been of great help here... > Cheers > Joris > > On Thu, May 27, 2010 at 1:25 PM, abanero <gdevi...@xtel.it> wrote: > > > > > Hi, > > > > thank you Joris and Ulrich for you answers. > > > > Joris Meys wrote: > > > > >see the library randomForest for example > > > > > > I'm trying to find some example in randomForest with categorical > variables > > but I haven't found anything. Do you know any example with both > categorical > > and numerical variables? Anyway I don't have any class labels yet. How > > could > > I find clusters with randomForest? > > > > > > Ulrich wrote: > > > > >Probably the simplest way is Affinity Propagation[...] All you need is a > > way of measuring the similarity of >samples which is straightforward both > > for numerical and categorical variables. > > > > I had a look at the documentation of the package apcluster. That's > > interesting but do you have any example using it with both categorical > and > > numerical variables? I'd like to test it with a large dataset.. > > > > Thanks a lot! > > Cheers > > > > Giuseppe > > > > -- > > View this message in context: > > > > http://r.789695.n4.nabble.com/cluster-analysis-and-supervised-classification-an-alternative-to-knn1-tp2231656p2232950.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. > > > > > > -- > Joris Meys > Statistical Consultant > > Ghent University > Faculty of Bioscience Engineering > Department of Applied mathematics, biometrics and process control > > Coupure Links 653 > B-9000 Gent > > tel : +32 9 264 59 87 > joris.m...@ugent.be > ------------------------------- > Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php > > [[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. > > > -- Joris Meys Statistical Consultant Ghent University Faculty of Bioscience Engineering Department of Applied mathematics, biometrics and process control Coupure Links 653 B-9000 Gent tel : +32 9 264 59 87 joris.m...@ugent.be ------------------------------- Disclaimer : http://helpdesk.ugent.be/e-maildisclaimer.php [[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.
