On Wed, 2 Apr 2003, Liaw, Andy wrote:

> Yves,
>
> I will add checks for NAs in predict.randomForest().
>
> In the next version of randomForest (currently called 3.9-x), there will be
> facilities for handling NAs in the training set.  However, there's no way to
> handle NAs in the test set yet.  I believe Leo is still working on that.
>
> In Leo's v.4 of the Fortran code, he uses proximity from random forest to
> iteratively impute NAs, starting with column median or mode (depending on
> variable types).  I've implemented this scheme at the R level, so that it
> works for both regression and classification.
>
> There are a couple of things in Leo's new code that I have not added to the
> package, and that's why the version is 3.9 rather than 4.0.  If you would
> like to test the new code, please let me know.

yes, sure!

best,

Torsten

>
> Cheers,
> Andy
>
> > -----Original Message-----
> > From: Yves Brostaux [mailto:[EMAIL PROTECTED]
> > Sent: Wednesday, April 02, 2003 8:34 AM
> > To: [EMAIL PROTECTED]
> > Cc: Liaw, Andy; Torsten Hothorn
> > Subject: RE: [R] randomForests predict problem
> >
> >
> > I use randomForest version 3.4-4, but yes, now I correctly
> > omitted NA's it
> > works. I should have made a mistake while removing them first time.
> >
> > I was surprised that this method doesn't have another way to
> > deal with NA's
> > than omitting them. As Torsten Hothorn suggested, the
> > associated predict
> > function should then check for NA's in newdata, shouldn't it ?
> >
> > Thank you both for your answers !
> >
> > At 15:12 02/04/03, Liaw, Andy wrote:
> > >Yves,
> > >
> > >Which version of the package are you using?  I get:
> > >
> > > > soy <- na.omit(Soybean)
> > > > ts <- sample(nrow(soy), 150, replace=FALSE)
> > > > sb.rf <- randomForest(Class ~ ., data=soy[-ts,])
> > > > table(predict(sb.rf, soy[ts,], type="class"))
> > >
> > >                2-4-d-injury         alternarialeaf-spot
> > >                           0                          37
> > >                 anthracnose            bacterial-blight
> > >                          10                           3
> > >           bacterial-pustule                  brown-spot
> > >                           2                          29
> > >              brown-stem-rot                charcoal-rot
> > >                          11                           7
> > >               cyst-nematode diaporthe-pod-&-stem-blight
> > >                           0                           0
> > >       diaporthe-stem-canker                downy-mildew
> > >                           4                           8
> > >          frog-eye-leaf-spot            herbicide-injury
> > >                          17                           0
> > >      phyllosticta-leaf-spot            phytophthora-rot
> > >                           3                           5
> > >              powdery-mildew           purple-seed-stain
> > >                           4                           5
> > >        rhizoctonia-root-rot
> > >                           5
> > >
> > >Cheers,
> > >Andy
> > >
> > > > -----Original Message-----
> > > > From: Yves Brostaux [mailto:[EMAIL PROTECTED]
> > > > Sent: Wednesday, April 02, 2003 4:46 AM
> > > > To: [EMAIL PROTECTED]
> > > > Subject: [R] randomForests predict problem
> > > >
> > > >
> > > > Hello everybody,
> > > >
> > > > I'm testing the randomForest package in order to do some
> > > > simulations and I
> > > > get some trouble with the prediction of new values. The
> > random forest
> > > > computation is fine but each time I try to predict values
> > > > with the newly
> > > > created object, I get an error message. I thought I was
> > > > because NA values
> > > > in the dataframe, but I cleaned them and still got the same
> > > > error. What am
> > > > I doing wrong ?
> > > >
> > > >  > library(mlbench)
> > > >  > library(randomForest)
> > > >  > data(Soybean)
> > > >  > test <- sample(1:683, 150, replace=F)
> > > >  > sb.rf <- randomForest(Class~., data=Soybean[-test,])
> > > >  > sb.rf.pred <- predict(sb.rf, Soybean[test,])
> > > > Error in matrix(t1$countts, nr = nclass, nc = ntest) :
> > > >          No data to replace in matrix(...)
> > > >
> > > > I did it the same way with rpart and all worked fine :
> > > >  > library(rpart)
> > > >  > sb.rp <- rpart(Class~., data=Soybean[-test,])
> > > >  > sb.rp.pred <- predict(sb.rp, Soybean[test,], type="class")
> > > >
> > > > Thank you all for any advice you can give to me.
> > > >
> > > > --
> > > > Ir. Yves Brostaux - Statistics and Computer Science Dpt.
> > > > Gembloux Agricultural University
> > > > 8, avenue de la Facult� B-5030 Gembloux (Belgium)
> > > > T�l : +32 (0)81 62 24 69
> > > > E-mail : [EMAIL PROTECTED]
> > > > Web : http://www.fsagx.ac.be/si/
> > > >
> > > > ______________________________________________
> > > > [EMAIL PROTECTED] mailing list
> > > > https://www.stat.math.ethz.ch/mailman/listinfo/r-help
> > > >
> > >
> > >-------------------------------------------------------------
> > -----------------
> > >Notice: This e-mail message, together with any attachments, contains
> > >information of Merck & Co., Inc. (Whitehouse Station, New
> > Jersey, USA)
> > >that may be confidential, proprietary copyrighted and/or legally
> > >privileged, and is intended solely for the use of the
> > individual or entity
> > >named on this message.  If you are not the intended
> > recipient, and have
> > >received this message in error, please immediately return
> > this by e-mail
> > >and then delete it.
> > >
> > >=============================================================
> > =================
> >
> >
>
>
> ------------------------------------------------------------------------------
> Notice: This e-mail message, together with any attachments, contains information of 
> Merck & Co., Inc. (Whitehouse Station, New Jersey, USA) that may be confidential, 
> proprietary copyrighted and/or legally privileged, and is intended solely for the 
> use of the individual or entity named on this message. If you are not the intended 
> recipient, and have received this message in error, please immediately return this 
> by e-mail and then delete it.
>
> ==============================================================================
>
>

______________________________________________
[EMAIL PROTECTED] mailing list
https://www.stat.math.ethz.ch/mailman/listinfo/r-help

Reply via email to