For the sake of anyone else asking this question....as Andy Liaw explained to me, yes, this is expected because predict() uses all the trees in the forest, including the ones based on any particular item in the input data frame.
Rodney -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Rodney Barnett Sent: Wednesday, October 01, 2008 10:01 AM To: r-help@r-project.org Subject: [R] Surprising randomForest Results Is it expected that predict.randomForest() produces the response vector when given the same data frame as provided to randomForest()? See below. Thanks. Rodney > rf <- randomForest (Species ~ ., iris) > pc <- predict (rf, iris) > confusion (pc, iris$Species) true object setosa versicolor virginica setosa 50 0 0 versicolor 0 50 0 virginica 0 0 50 attr(,"error") [1] 0 > confusion (rf$predicted, iris$Species) true object setosa versicolor virginica setosa 50 0 0 versicolor 0 47 3 virginica 0 3 47 attr(,"error") [1] 0.04 > rf$confusion setosa versicolor virginica class.error setosa 50 0 0 0.00 versicolor 0 47 3 0.06 virginica 0 3 47 0.06 > ______________________________________________ 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.
