[R] help with the usage of "randomForest"

[Torsten Hothorn]

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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