Short answer: Not really. Slightly longer answer: from what I remember of partitioning methods, a given split is made at either a single observation or between two consecutive observations. In your case, I estimate rpart would have split on that particular point... except that there are 6 of them now. So the choice of which 6 to split is arbitrary. (Someone with more knowledge of rpart's guts feel free to correct me). -------------------------------------- Jonathan P. Daily Technician - USGS Leetown Science Center 11649 Leetown Road Kearneysville WV, 25430 (304) 724-4480 "Is the room still a room when its empty? Does the room, the thing itself have purpose? Or do we, what's the word... imbue it." - Jubal Early, Firefly
r-help-boun...@r-project.org wrote on 12/02/2010 05:34:23 AM: > [image removed] > > [R] rpart results - problem after oversampling > > Mederos, Vicente (Santander) > > to: > > r-help@r-project.org > > 12/02/2010 05:36 AM > > Sent by: > > r-help-boun...@r-project.org > > Hi all, > > I am trying to predict a target variable that takes values 0 or 1 > using the rpart command. In my initial dataset I have few positive > observations of the target variable; therefore I have oversampled > the rare event by a multiple of 6 (i.e. from 762 to 4572). > > However, in my results, I end up with a number of positives in one > of the terminal nodes that is not divisible by 6. As I have the same > observation repeated 6 times, shouldn't all of them follow the same > branch of the tree and go to the same terminal node? > > Thanks for your help, > > Vicente > Emails aren't always secure, and they may be intercepted or changed > after they've been sent. Santander doesn't accept liability if this > happens. If you think someone may have interfered with this email, > please get in touch with the sender another way. This message doesn't > create or change any contract. Santander doesn't accept responsibility > for damage caused by any viruses contained in this email or its > attachments. Emails may be monitored. If you've received this email by > mistake, please let the sender know at once that it's gone to the wrong > person and then destroy it without copying, using, or telling anyone > about its contents. Santander UK plc (SAN UK) Reg. No. 2294747 and Abbey > National Treasury Services plc (ANTS) Reg. No. 2338548 are registered in > England and have their Registered Offices at 2 Triton Square, Regent's > Place, London, NW1 3AN. www.santander.co.uk SAN UK and ANTS are > authorised and regulated by the Financial Services Authority (Reg. No. > 106054 and 146003 respectively). SAN UK advises on mortgages, a limited > range of life assurance, pension and collective investment scheme > products and acts as an insurance intermediary for general insurance. > Santander and the flame logo are registered trademarks. > Ref:[PDB#1-4] > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@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@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.