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
