Thank you very much for this clarification, Sincerely, Fabon Dzogang.
2010/11/15 Uwe Ligges <lig...@statistik.tu-dortmund.de>: > > > On 03.11.2010 16:26, Fabon Dzogang wrote: >> >> Hi, >> >> I run R 2.10.1 under ubuntu 10.04 LTS (Lucid Lynx) and klaR version 0.6-4. >> >> I compute a model over a 2 classes dataset (composed of 700 examples). >> To that aim, I use the function NaiveBayes provided in the package >> klaR. >> When I then use the prediction function : predict(my_model, new_data). >> I get the following warning : >> >> "In FUN(1:747[[747L]], ...) : Numerical 0 probability with observation >> 458" >> >> As I did not find any documentation or any discussion concerning this >> warning message, I looked in the klaR source code and found the >> following line in predict.NaiveBayes.R : >> >> "warning("Numerical 0 probability with observation ", i)" > > > Within Naive Bayes in order to calculate the posteriori probabilities of > the classes it is necessary to calculate the probabilities of the > observations given the classes. The function NaiveBayes prints a warning > if all these probabilities are numerical 0, i.e. that the observation > has a numerical probability of 0 for *all* classes. Usually this is only > the case when the obs. is an extreme outlier. > > I will change the warning to say "all classes" in further releases of klaR. > > Best wishes, > Uwe Ligges > > > >> Unfortunately, it is hard to get a clear picture of the whole process >> reading the code. I wonder if someone could help me with the meaning >> of this warning message. >> >> Sorry I did not provide an example, but I could not simulate the same >> message over a small toy example. >> >> Thank you, >> >> Fabon Dzogang. >> >> ______________________________________________ >> 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. > -- Fabon Dzogang ______________________________________________ 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.