[R] randomForest

[Liaw, Andy]

Uwe had been right all along.  I don't understand what you don't
understand from the documentation.

You can use sampsize=c(300, 300) and replace=FALSE to make sure that all
300 class 1 rows are used, but be warned that that leaves no rows for
OOB estimate.

Andy 

From: Anirudh Kondaveeti
> 
> To be more clear,
> 
> My data set contains two classes.. Class 1 and Class 2
> Class 1 has original data with 300 rows
> Class 2 is randomly generated data with 1500 rows.
> 
> I want to sample a new data set with
> Class 1 - all the rows
> Class 2 - only 300 rows out of 1500 rows
> 
> and then use it in random forest with 500 trees.
> 
> Also the Class 2 should have different 300 rows for different 
> trees in the
> forest. Thanks!
> 
> Anirudh Kondaveeti
> ----------------------------
> 
> 
> On Fri, Mar 20, 2009 at 1:45 PM, Anirudh Kondaveeti <
> anirudh.kondaveeti at gmail.com> wrote:
> 
> > sampsize uses the same sample for all the trees in the 
> random Forest.
> >
> > But I want to use different sample for each tree of the 500 
> trees in the
> > random Forest. Thanks!
> >
> >
> > Anirudh Kondaveeti
> > ----------------------------
> >
> >
> > 2009/3/20 Uwe Ligges <ligges at statistik.tu-dortmund.de>
> >
> >
> >>
> >> Anirudh Kondaveeti wrote:
> >>
> >>> Hi!
> >>>
> >>> I am dealing with random forest using R.
> >>>
> >>> Is there a way to sample a fixed no.of rows from a 
> dataset for use with
> >>> different trees in random Forest.
> >>> To be more clear, my data set contains 1500 rows, and I 
> am growing 500
> >>> trees
> >>> in Random Forest
> >>> Is it possible to sample only 500 rows of data from the 
> data set and use
> >>> it
> >>> for different trees in the forest. I mean each tree of 
> the forest should
> >>> use
> >>> a different 500 rows from the data set.
> >>>
> >>
> >>
> >> See ?randomForest and the argument sampsize.
> >>
> >> Uwe Ligges
> >>
> >>
> >>
> >>
> >>> Thanks in advance!
> >>>
> >>> Anirudh Kondaveeti
> >>> ----------------------------
> >>>
> >>>        [[alternative HTML version deleted]]
> >>>
> >>> ______________________________________________
> >>> R-help at 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.
> >>>
> >>
> >
> 
> 	[[alternative HTML version deleted]]
> 
> ______________________________________________
> R-help at 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:12}}