Re: [R] rpart and randomforest results

2014-04-08 Thread John Maindonald
un...@r-project.org> [mailto:r-help-boun...@r-project.org] On Behalf Of Schillo, Sonja Sent: Thursday, April 03, 2014 3:58 PM To: Mitchell Maltenfort Cc: r-help@r-project.org<mailto:r-help@r-project.org> Subject: Re: [R] rpart and randomforest results Hi, the random forest should do that,

Re: [R] rpart and randomforest results

2014-04-07 Thread Liaw, Andy
Sent: Thursday, April 03, 2014 3:58 PM To: Mitchell Maltenfort Cc: r-help@r-project.org Subject: Re: [R] rpart and randomforest results Hi, the random forest should do that, you're totally right. As far as I know it does so by randomly selecting the variables considered for a split (but here w

Re: [R] rpart and randomforest results

2014-04-03 Thread Schillo, Sonja
" from the randomforest away. Is that plausible and does anyone have another idea? Thanks Sonja Von: Mitchell Maltenfort [mailto:mmal...@gmail.com] Gesendet: Dienstag, 1. April 2014 13:32 An: Schillo, Sonja Cc: r-help@r-project.org Betreff: Re: [R] rpart and randomforest results Is it possible

Re: [R] rpart and randomforest results

2014-04-01 Thread Mitchell Maltenfort
Is it possible that the random forest is somehow adjusting for optimism or overfitting? On Apr 1, 2014 7:27 AM, "Schillo, Sonja" wrote: > Hi all, > > I have a question on rpart and randomforest results: > > We calculated a single regression tree using rpart and got a pseudo-r2 of > roundabout 10%

[R] rpart and randomforest results

2014-04-01 Thread Schillo, Sonja
Hi all, I have a question on rpart and randomforest results: We calculated a single regression tree using rpart and got a pseudo-r2 of roundabout 10% (which is not too bad compared to a linear regression on this data). Encouraged by this we grew a whole regression forest on the same data set u