o ha wang wrote: > Hi all, > > Can anyone who is familar with CART tell me what I missed in my tree code? > > library (MASS) > myfit <- tree (y ~ x1 + x2 + x3 + x4 )
There is not function tree() in MASS. I guess you have loaded package "tree"? Note that the author and maintainer of the tree package suggests to use package rpart instead. > # tree.screens () # useless > plot(myfit); text (myfit, all= TRUE, cex=0.5, pretty=0) > # tile.tree (myfit, fgl$type) # useless > # close.screen (all= TRUE) # useless > > > My current tree plot resulted from above code shows as: > 1. overlapped #s caused by unsuitable length of branch. > 2. no misclassification rates: 'misclass.tree' only brings up the error of > ' misclassification error rate is appropriate for factor responses only', but > my response y is 0/1 data. If you data is 0/1, you should make it a factor otherwise the cose will assume you want a regression rather than a classification tree. > 3. Unsuitable location of notations: there are not two notation of > splitting criteria on the two branches when a node is split, instead only one > notation of splitting criteria is on the node location. It indicates which items go into the left branch. Uwe Ligges > > thanks, > xiao yue > > > --------------------------------- > > [[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. ______________________________________________ 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.
