I am trying to run a partialPlot with Random Forest (as I have done many times before).
First I run my forest... Cell is a 6 level factor that is the dependent variable - all other variables are predictors, most of these are factors as well. predCell<-randomForest(x=tempdata[-match("Cell",names(tempdata))],y=tempdata$Cell,importance=T) Then I try my partial plot to look at the effect of a specific predictor. partialPlot(x=predCell,pred.data=tempdata[-match("Cell",names(tempdata))],x.var="P7_6") I get this error: Error in predict.randomForest(x, x.data, type = "prob") : Type of predictors in new data do not match that of the training data. In examining randomForest:::predict.randomForest I see the following code that produces this error message. cat.new <- sapply(x, function(x) if (is.factor(x) && !is.ordered(x)) length(levels(x)) else 1) if (!all(object$forest$ncat == cat.new)) stop("Type of predictors in new data do not match that of the training data.") } The odd thing is that if I run this code outside of the function: > all(predCell$forest$ncat== + sapply(tempdata[-match("Cell",names(tempdata))], function(x) if (is.factor(x) && + !is.ordered(x)) + length(levels(x)) + else 1)) [1] TRUE Which should avoid the "stop" function. Here is the session info. R version 2.8.1 (2008-12-22) i386-pc-mingw32 locale: LC_COLLATE=English_United States.1252;LC_CTYPE=English_United States.1252;LC_MONETARY=English_United States.1252;LC_NUMERIC=C;LC_TIME=English_United States.1252 attached base packages: [1] stats graphics grDevices utils datasets methods base other attached packages: [1] randomForest_4.5-30 > Any ideas would be greatly appreciated. W. Michael Conklin Chief Methodologist MarketTools, Inc. | www.markettools.com<http://www.markettools.com> 6465 Wayzata Blvd | Suite 170 | St. Louis Park, MN 55426. PHONE: 952.417.4719 | CELL: 612.201.8978 This email and attachment(s) may contain confidential and/or proprietary information and is intended only for the intended addressee(s) or its authorized agent(s). Any disclosure, printing, copying or use of such information is strictly prohibited. If this email and/or attachment(s) were received in error, please immediately notify the sender and delete all copies [[alternative HTML version deleted]] ______________________________________________ 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.