> Finally figured it out. You have to extract it from the attributes. > Tricky. Thanks anyway.
> attr(pred, "prob")[1:10,] Correct. Just for the records, the rationale behind this `tricky' design: In addition to probabilites, predict.svm() (more precisely: libsvm) can also compute the decision values. Common ways to handle `polymorph' prediction types are, e.g, using a `type' argument in the predict() function, or to return all variants in one list object. With a `type' argument, you need several calls to predict() if you need, say, hard predictions _and_ the probabilities. On the other hand, the probability and decision values features were added to libsvm only when svm() in e1071 had already been around for a while, so returning a list instead of a vector would have broken a lot of code. So I decided to keep the `standard' predict behavior and to `hide' special predictions in an attribute. If the latter had been available from the beginning, I probably would have used the `type' approach. Cheers, David On 2/16/06, roger bos <[EMAIL PROTECTED]> wrote: > > I am using SVM to classify categorical data and I would like the > probabilities instead of the classification. ?predict.svm says that its > only enabled when you train the model with it enabled, so I did that, but it > didn't work. I can't even get it to work with iris. The help file shows > that probability = TRUE when training the model, but doesn't show an > example. Then I try to predict with probabilities, I still only get > classifications back. Anyone get this to work and can help me out? -- Dr. David Meyer Department of Information Systems and Operations Vienna University of Economics and Business Administration Augasse 2-6, A-1090 Wien, Austria, Europe Fax: +43-1-313 36x746 Tel: +43-1-313 36x4393 HP: http://wi.wu-wien.ac.at/~meyer/ ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
