Alternatively, if you can arrive at a sensible ordering of the levels you can declare them ordered factors and make the computation feasible once again.
Bill Venables. -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Torsten Hothorn Sent: Monday, 5 April 2004 4:27 PM To: David L. Van Brunt, Ph.D. Cc: R-Help Subject: Re: [R] Can't seem to finish a randomForest.... Just goes and goes! On Sun, 4 Apr 2004, David L. Van Brunt, Ph.D. wrote: > Playing with randomForest, samples run fine. But on real data, no go. > > Here's the setup: OS X, same behavior whether I'm using R-Aqua 1.8.1 > or the Fink compile-of-my-own with X-11, R version 1.8.1. > > This is on OS X 10.3 (aka "Panther"), G4 800Mhz with 512M physical > RAM. > > I have not altered the Startup options of R. > > Data set is read in from a text file with "read.table", and has 46 > variables and 1,855 cases. Trying the following: > > The DV is categorical, 0 or 1. Most of the IV's are either continuous, > or correctly read in as factors. The largest factor has 30 levels.... > Only the ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ This means: there are 2^(30-1) = 536.870.912 possible splits to be evaluated everytime this variable is picked up (minus something due to empty levels). At least the last time I looked at the code, randomForest used an exhaustive search over all possible splits. Try reducing the number of levels to something reasonable (or for a first shot: remove this variable from the learning sample). Best, Torsten > DV seems to need identifying as a factor to force class trees over > regresssion: > > >Mydata$V46<-as.factor(Mydata$V46) > >Myforest.rf<-randomForest(V46~.,data=Mydata,ntrees=100,mtry=7,proximi > >ties=FALSE > , importance=FALSE) > > 5 hours later, R.bin was still taking up 75% of my processor. When > I've tried this with larger data, I get errors referring to the buffer > (sorry, not in front of me right now). > > Any ideas on this? The data don't seem horrifically large. Seems like > there are a few options for setting memory size, but I'm not sure > which of them to try tweaking, or if that's even the issue. > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! > http://www.R-project.org/posting-guide.html > > ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
