[R] help with the usage of "randomForest"

[Hui Han]

Thanks for Matt and Torsten for very helpful suggestions!
As Matt pointed out, the problem is that na.action has the default value of na.fail, that
deleted one class samples. I changed all NAs to real values, and the error msg.
dissappeared. 

However my real dataset contains many NAs. I wonder if anybody can point me any documentations on
how to define na.action not be na.fail?

Best regards,
Hui

On Wed, Mar 31, 2004 at 06:26:36PM +0200, Torsten Hothorn wrote:
> On Wed, 31 Mar 2004, Hui Han wrote:
> 
> > Dear all,
> >
> > Can anybody give me some hint on the following error msg I got with using
> > randomForest?
> >
> > I have two-class classification problem. The data file "sample" is:
> > ----------------------------------------------------------
> >  udomain.edu udomain.hcs hpclass
> > 1 1.0000 1 not
> > 2 NA 2 not
> > 3 NA 0.8 not
> > 4 NA 0.2 hp
> > 5 NA 0.9 hp
> > ------------------------------------------------------------
> > The steps I called the function are:
> > (1) Read data
> > hp <- read.table("sample")
> 
> most probably a problem here. say
> 
> R> summary(hp)
> 
> and check if the factor `hpclass' has two levels.
> 
> Torsten
> 
> > (2) Call randomForest
> > hp.rf <- randomForest(hpclass ~., yy, data=hp, importance=TRUE,
> > proximity=TRUE)
> >
> > But the error msg I got is:
> > Error in randomForest.default(m, y, ...) :
> >         Need at least two classes to do classification.
> >
> >
> > I learned the usage of randomForest from:
> > http://www.maths.lth.se/help/R/.R/library/randomForest/html/randomForest.html
> >
> > Thanks a lot for any of your comments in advance!
> >
> >
> > Hui Han
> > Department of Computer Science and Engineering,
> > The Pennsylvania State University
> > University Park, PA,16802
> > email: hhan at cse.psu.edu
> > homepage: http://www.cse.psu.edu/~hhan
> >
> > ______________________________________________
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> > https://www.stat.math.ethz.ch/mailman/listinfo/r-help
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> >
> >


Hui Han
Department of Computer Science and Engineering,
The Pennsylvania State University 
University Park, PA,16802
email: hhan at cse.psu.edu
homepage: http://www.cse.psu.edu/~hhan