[R] Strange error with ROCR

Hello, I've come across a strange error... Here is what happens: model - svm(traindata,trainlabels, type=C-classification, kernel=radial, cost=10, class.weights=c(win=3,lose=1), scale=FALSE, probability = TRUE) predictions - predict(model, traindata) pred - prediction(predictions,

Re: [R] Strange error with ROCR

Hi, you need the score value , have a look at ?svm.predict and in the ROCR example. traindata - as.data.frame(matrix(runif(1000),ncol=10)) trainlabels - as.factor(sample(c(win,lose),nrow(data),replace=T,prob=c(0.5,0.5))) model - svm(traindata,trainlabels, type=C-classification,

Re: [R] Strange error with ROCR

Good point. I'm not sure how I missed that. This does lead to an additional question: Is the probability of the true label the best prediction to feed to the ROCR package, or is it better to use the decision.value Anybody have any experience on this one? Thanks! -N On 8/4/09 3:28 AM,

Re: [R] Strange error with ROCR

Is the probability of the true label the best prediction to feed to the ROCR package, or is it better to use the decision.value Since AFAIK they are related by a monotonous transformation, both approaches should lead to the same ROC curve, shouldn't they? (not tested) On Tue, Aug 4, 2009 at

Re: [R] Strange error with ROCR

I hadn't thought of that. I'll run some tests... -N On 8/4/09 11:49 AM, Tobias Sing wrote: Is the probability of the true label the best prediction to feed to the ROCR package, or is it better to use the decision.value Since AFAIK they are related by a monotonous transformation, both