Have a look at the function arguments. I think the function may not split a set of fewer than 20 objects, which is a default setting that can be changed. In addition to rpart, you might want to look at tree. regards, Farrar
Wensui Liu <[EMAIL PROTECTED]> wrote: with seeing more code and output, i guess your tree fails to grow. On 2/28/07, Claudia Romero wrote: > Hello, > This is my first time addressing such a big audience so apologies in > advance in case I fail to formulate this question. > > I am working with 13 species of trees, and the data I have are: > 1 continuous (phenolic concentration in xylem and in phloem) and 2 > categorical variables: lineage (3 subclades) and habitat (fire and non > fire). > > I am trying to see how species can be splitted 'objectively' based on > these variables. I tried to do a regression tree using the rpart > library, but repeatedly got the following answer, even when I tried to > run it using ONLY the categorical variables: > > > plot(fit, compress=TRUE) > Error in plot.rpart(fit, compress = TRUE) : > fit is not a tree, just a root > > Can anyone please help me think about this? > > Many thanks, > claudia romero > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > -- WenSui Liu A lousy statistician who happens to know a little programming (http://spaces.msn.com/statcompute/blog) ______________________________________________ R-help@stat.math.ethz.ch 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. [[alternative HTML version deleted]] ______________________________________________ R-help@stat.math.ethz.ch 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.