Thank you very much. I'll jump in to the data and verify the consistency between the training and testing variables and their levels.
On Fri, Mar 7, 2008 at 5:14 PM, <[EMAIL PROTECTED]> wrote: > The error message is pretty clear, really. To spell it out a bit more, > what you have done is as follows. > > Your training set has factor variables in it. Suppose one of them is > "f". In the training set it has 5 levels, say. > > Your test set also has a factor "f", as it must, but it appears that in > the test set it has 6 levels, or more, or levels that do not agree with > those for "f" in the training set. > > This mismatch measn that the predict method for randomForest cannot use > this test set. > > What you have to do is make sure that the factor levels agree for every > factor in both test and training set. One way to do this is to put the > test and training set together with rbind(...) say, and then separate > them again. But even this will still have a problem for you. Because > you training set will have some factor levels empty, which are not empty > in the test set. The error will most likely be more subtle, though. > > You really need to sort this out yourself. It is not particularly an R > problem, but a confusion over data. To be useful, your training set > need to cover the field for all levels of every factor. Think about it. > > > > -----Original Message----- > From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] > On Behalf Of Nagu > Sent: Saturday, 8 March 2008 5:37 AM > To: r-help@r-project.org; [EMAIL PROTECTED] > Subject: [R] error in random forest > > Hi, > > I get the following error when I try to predict the probabilities of a > test sample: > > Error in predict.randomForest(fit.EBA.OM.rf.50, x.OM, type = "prob") : > New factor levels not present in the training data > > I have about 630 predictor variables in the dataset x.OM (25 factor > variables and the remaining are continuous variables). Any ideas on > how to trace it? > > Thank you, > Nagu > > ______________________________________________ > R-help@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. > > > ______________________________________________ R-help@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.
