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 < > [email protected]> 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 <[email protected]> > > > > > >> > >> 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]] > >>> > >>> ______________________________________________ > >>> [email protected] 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]] > > ______________________________________________ > [email protected] 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}} ______________________________________________ [email protected] 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.
