[R] Rpart - best split selection for class method and Gini splitting index

[Paolo Radaelli]

Dear R-users,
I'm working with the Rpart package and trying to understand how the 
procedure select the best split in the case the method "class" and the 
splitting index "Gini" are used. In particular I'd like to have look to the 
source code that works out the best split for un unordered predictor.
Does anyone can suggest me which functions in the sources I should consider 
?
Any input would be highly appreciated.

Thank you
Paolo

Paolo Radaelli
Dipartimento di Metodi Quantitativi per le Scienze Economiche ed Aziendali
Facoltà di Economia
Università degli Studi di Milano-Bicocca
Via Bicocca degli Arcimboldi, 8
20126 Milano
Italy
e-mail paolo.radaelli at unimib.it
Tel +39 02 6448 3163
Fax +39 02 6448 3105