Take a look at the levels of 'owner'. On Mon, 11 Feb 2008, Amnon Melzer wrote:
> Hi > > > > Hoping someone can help me (a newbie). > > > > I am trying to construct a tree using tree() in package tree. One of the > fields is a factor field (owner), with many levels. In the resulting tree, I > see many NA's (see below), yet in the actual data there are none. You are misinterpreting this: those are level names. Using a tree with a factor with many levels is a very bad idea: it takes a long time to compute (unless the response is binary) and almost surely overfits. > > >> rr200.tr <- tree(backprof ~ ., rr200) > >> rr200.tr > > 1) root 200 1826.00 -0.2332 > > ... > > [snip] > > ... > > 5) owner: Cliveden Stud,NA,NA,NA,NA,NA,NA,NA,NA 10 14.25 1.5870 * > > 3) owner: B E T Partnership,Flaming Sambuca > Syndicate,NA,NA,NA,NA,NA,NA,NA,NA 11 384.40 10.5900 > > 6) decodds < 12 5 74.80 6.3000 * > > 7) decodds > 12 6 140.80 14.1700 * > > > > Can anyone tell me why this happens and what I can do about it? Well, you could follow the request at the footer of this and every R-help message. > > > Regards > > > > Amnon > > > > > [[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. > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ 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.
