Hello, I want to try oblique decision tree. I have found the mvpart package. In the help file, there is an example of the mvpart function using the spider data set. However, when trying the example I do not obtain an oblique decision tree with separating rules such as p1+p2<5, but rather simple rules of the form p1>3. Is it normal? Thanks for your replies. Sandro. -- View this message in context: http://www.nabble.com/Oblique-decision-tree-using-mvpart-tp19285410p19285410.html Sent from the R help mailing list archive at Nabble.com.
On Wed, 3 Sep 2008, Clusty wrote:> I want to try oblique decision tree. I have found the mvpart package. In theWhat gave you the idea that mvpart was an implementation of oblique decision trees? It does not say so anywhere.> help file, there is an example of the mvpart function using the spider data > set. However, when trying the example I do not obtain an oblique decision > tree with separating rules such as p1+p2<5, but rather simple rules of the > form p1>3. Is it normal?Yes. As the task view that I pointed you previously explains An adaptation of rpart for multivariate responses is available in package mvpart. Thus, this is for multivariate *responses*, not for multivariate splits. Z> Thanks for your replies. > Sandro. > -- > View this message in context: http://www.nabble.com/Oblique-decision-tree-using-mvpart-tp19285410p19285410.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help at 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. > >
First, thanks for your answer. I find the description of mvpart package quite short: "Wrapper function for fitting and plotting rpart models " Then, I thought that mvpart was the package which seems closest to what I would like to do (i.e. oblique decision tree also named multivariate decision tree). However, as you pointed out, it is the answer which is multivariate in the mvpart package.> Thus, this is for multivariate *responses*, not for multivariate splits.So, to your knowledge, there is no R package for multivariate splits (i.e. oblique decision trees)? Thanks. Sandro.> ______________________________________________ > R-help at 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 at 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. -- View this message in context: http://www.nabble.com/Oblique-decision-tree-using-mvpart-tp19285410p19287202.html Sent from the R help mailing list archive at Nabble.com.
On Wed, 3 Sep 2008, Clusty wrote:> > > First, thanks for your answer. > I find the description of mvpart package quite short: > > "Wrapper function for fitting and plotting rpart models " > > Then, I thought that mvpart was the package which seems closest to what I > would like to do (i.e. oblique decision tree also named multivariate > decision tree). However, as you pointed out, it is the answer which is > multivariate in the mvpart package. > >> Thus, this is for multivariate *responses*, not for multivariate splits. > > So, to your knowledge, there is no R package for multivariate splits (i.e. > oblique decision trees)?I know of such packages, but no public ones. -- 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 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595
On Wed, 3 Sep 2008, Clusty wrote:> First, thanks for your answer. > I find the description of mvpart package quite short: > > "Wrapper function for fitting and plotting rpart models "I agree that this could be improved.> Then, I thought that mvpart was the package which seems closest to what I > would like to do (i.e. oblique decision tree also named multivariate > decision tree). However, as you pointed out, it is the answer which is > multivariate in the mvpart package.Terminology for different flavors of decision trees and recursive partitioning varies a lot between different communities (machine learning, artificial intelligence, statistical learning, ...) and even within communities.>> Thus, this is for multivariate *responses*, not for multivariate splits. > > So, to your knowledge, there is no R package for multivariate splits (i.e. > oblique decision trees)?No, to the best of my knowledge, the list in the Machine Learning task view is up to date. Also, I think that "oblique decision trees" is specific to the algorithm underlying the OC1 implementation. http://www.cs.jhu.edu/~salzberg/announce-oc1.html The term trees with "functional splits" or "multiway splits" is more common, I guess. Binaries for the original implementation of the CRUISE algorithm are available at http://www.stat.wisc.edu/~loh/cruise.html We played around with interfacing the latter in R, but unfortunately that is not really finished, yet. hth, Z