Re: [R] memory problems when combining randomForests

2006-08-01 Thread Ramon Diaz-Uriarte
Dear Eleni, > > But if every time you remove a variable you pass some test data (ie data > not used to train the model) and base the performance of the new, reduced > model on the error rate on the confusion matrix for the test data, then > this "overfitting" should not be an issue, right? (unles

Re: [R] memory problems when combining randomForests

2006-07-31 Thread Weiwei Shi
Found it from another paper: importance sample learning ensemble (ISLE) which originates from Friedman and Popescu (2003). On 7/31/06, Weiwei Shi <[EMAIL PROTECTED]> wrote: > > Hi, Andy: > > What's the Jerry Friedman's ISLE? I googled it and did not find the paper > on it. Could you give me a lin

Re: [R] memory problems when combining randomForests [Broadcast]

2006-07-31 Thread Liaw, Andy
ndy; r-help@stat.math.ethz.ch Subject: Re: [R] memory problems when combining randomForests [Broadcast] Hi, Andy: What's the Jerry Friedman's ISLE? I googled it and did not find the paper on it. Could you give me a link, please? Thanks, Weiwei On 7/31/06, Eleni Rapsomaniki <[EMAIL P

Re: [R] memory problems when combining randomForests

2006-07-31 Thread Eleni Rapsomaniki
Hi Andy, > > I get different order of importance for my variables depending on their order in the training data. Perhaps answering my own question, the change in importance rankings could be attributed to the fact that before passing my data to randomForest I impute the missing values randomly (u

Re: [R] memory problems when combining randomForests

2006-07-31 Thread Weiwei Shi
Hi, Andy: What's the Jerry Friedman's ISLE? I googled it and did not find the paper on it. Could you give me a link, please? Thanks, Weiwei On 7/31/06, Eleni Rapsomaniki <[EMAIL PROTECTED]> wrote: > > Hello > > I've just realised attachments are not allowed, so the data for the > example in > m

Re: [R] memory problems when combining randomForests

2006-07-31 Thread Eleni Rapsomaniki
Hello I've just realised attachments are not allowed, so the data for the example in my previous message is: pos.df=read.table("http://www.savefile.com/projects3.php?fid=6240314&pid=847249&key=119090";, header=T) neg.df=read.table("http://fs07.savefile.com/download.php?pid=847249&fid=9829834&key

Re: [R] memory problems when combining randomForests

2006-07-29 Thread Eleni Rapsomaniki
Hello again, The reason why I thought the order at which rows are passed to randomForest affect the error rate is because I get different results for different ways of splitting my positive/negative data. First get the data (attached with this email) pos.df=read.table("C:/Program Files/R/rw2011/

Re: [R] memory problems when combining randomForests

2006-07-28 Thread Liaw, Andy
From: Eleni Rapsomaniki > > Hi Andy, > > > > I'm using R (windows) version 2.1.1, randomForest version 4.15. > >^ > > Never seen such a version... > Ooops! I meant 4.5-15 > > > > I then save each tree to a file so I can combine

Re: [R] memory problems when combining randomForests

2006-07-28 Thread Eleni Rapsomaniki
Hi Andy, > > I'm using R (windows) version 2.1.1, randomForest version 4.15. >^ > Never seen such a version... Ooops! I meant 4.5-15 > > I then save each tree to a file so I can combine them all > > afterwards. There are no memo

Re: [R] memory problems when combining randomForests

2006-07-27 Thread Liaw, Andy
From: Eleni Rapsomaniki > > I'm using R (windows) version 2.1.1, randomForest version 4.15. ^ Never seen such a version... > I call randomForest like this: > > my.rf=randomForest(x=train.df[,-response_index], > y=train.df[,respons

Re: [R] memory problems when combining randomForests [Broadcast]

2006-07-27 Thread Eleni Rapsomaniki
I'm using R (windows) version 2.1.1, randomForest version 4.15. I call randomForest like this: my.rf=randomForest(x=train.df[,-response_index], y=train.df[,response_index], xtest=test.df[,-response_index], ytest=test.df[,response_index], importance=TRUE,proximity=FALSE, keep.forest=TRUE) (whe

Re: [R] memory problems when combining randomForests [Broadcast]

2006-07-26 Thread Liaw, Andy
You need to give us more details, like how you call randomForest, versions of the package and R itself, etc. Also, see if this helps you: http://finzi.psych.upenn.edu/R/Rhelp02a/archive/32918.html Andy From: Eleni Rapsomaniki > > Dear all, > > I am trying to train a randomForest using all my

[R] memory problems when combining randomForests

2006-07-26 Thread Eleni Rapsomaniki
Dear all, I am trying to train a randomForest using all my control data (12,000 cases, ~ 20 explanatory variables, 2 classes). Because of memory constraints, I have split my data into 7 subsets and trained a randomForest for each, hoping that using combine() afterwards would solve the memory issue