[R] Surrogate splits for decision trees
Prof Brian Ripley
ripley at stats.ox.ac.uk
Wed May 23 08:03:00 CEST 2001
On Tue, 22 May 2001, Thomas Lumley wrote:
> On Tue, 22 May 2001, Clayton Springer wrote:
> > Dear R,
> > Short verse of the question:
> > Is there R code which will calculate surrogate splits
> > and/or delta impurity for decision trees at each node?
> package rpart
> > Long Version:
> > I have local, legacy code which I use to calculate my decision trees.
> > I would like to switch to R, but as I understand it surrogate splits
> > are not implemented.
> > Surrogate splits and feature ranking are described in Breiman et al
> > "CART" 1984. Curiously, they don't seem to appear anywhere else
> > in the literature.
> The rpart package contains tree code that does implement surrogate splits.
> It is not particularly extensible now, but the next version is planned to
> be very extensible.
And I am porting a pre-release of that version to R right now.
Brian D. Ripley, ripley at stats.ox.ac.uk
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 272860 (secr)
Oxford OX1 3TG, UK Fax: +44 1865 272595
r-help mailing list -- Read http://www.ci.tuwien.ac.at/~hornik/R/R-FAQ.html
Send "info", "help", or "[un]subscribe"
(in the "body", not the subject !) To: r-help-request at stat.math.ethz.ch
More information about the R-help