Hi, I think most, if not all, your questions can be answered by:
1) ?rpart 2) Some search through the r-help mailing list 3) Read the chapter on tree-based models in MASS 4 (Modern Applied Statistics with S) by Venables and Ripley Kevin ----- Original Message ----- From: <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Friday, June 04, 2004 9:59 PM Subject: [R] rpart > Hello everyone, > > I'm a newbie to R and to CART so I hope my questions don't seem too stupid. > > 1.) > My first question concerns the rpart() method. Which method does rpart use in > order to get the best split - entropy impurity, Bayes error (min. error) or Gini > index? Is there a way to make it use the entropy impurity? > > The second and third question concern the output of the printcp() function. > 2.) > What exactly are the cps in that sense here? I assumed them to be the treshold > complexity parameters as in Breiman et al., 1998, Section 3.3? Are they the same > as the treshold niveaus of alpha? I have read somewhere that the cps here are > the treshold alphas divided by the root node error. Is that true? > > 3.) > How is rel error computed? > I am supposed to evaluate the goodness of classification of of the CART method. > Do you think rel error is a good measure for that? > > I'd be very thankful if anyone could give me hand on that. This is a project for > uni and I desperately need a good mark. > > Thank you very much in advance, > > Mareike > > ______________________________________________ > [EMAIL PROTECTED] mailing list > https://www.stat.math.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > ______________________________________________ [EMAIL PROTECTED] mailing list https://www.stat.math.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html