Hello all, I have two problems with the ROCR package.
First Problem: the add=TRUE option does not work for plotting performance objects The following code is taken from the reference manual (example for ROCR.hiv, page2) data(ROCR.hiv) attach(ROCR.hiv) pred.svm <- prediction(hiv.svm$predictions, hiv.svm$labels) perf.svm <- performance(pred.svm, 'tpr', 'fpr') pred.nn <- prediction(hiv.nn$predictions, hiv.svm$labels) perf.nn <- performance(pred.nn, 'tpr', 'fpr') plot(perf.svm, lty=3, col="red",main="SVMs and NNs for prediction of HIV-1 coreceptor usage") now I see some dotted red ROC curves. Now after the next command: plot(perf.nn, lty=3, col="blue",add=TRUE) there happens exactly the same as if i would call: plot(perf.nn, lty=3, col="blue") I now see only some dotted blue ROC curves, the red ones and the main caption of the plot are gone. Second problem: the averaging of multiple performance curves does not work correctly (using the same example code, skipping some comands) data(ROCR.hiv) attach(ROCR.hiv) pred.svm <- prediction(hiv.svm$predictions, hiv.svm$labels) perf.svm <- performance(pred.svm, 'tpr', 'fpr') pred.nn <- prediction(hiv.nn$predictions, hiv.svm$labels) perf.nn <- performance(pred.nn, 'tpr', 'fpr') plot(perf.svm, avg="vertical", lwd=3, col="red", spread.estimate="stderror",plotCI.lwd=2) this does not give me an average curve, but multiple ones: see screenshot: http://www-stud.uni-due.de/~sfhestra/Bildschirmfoto.png I already tried reinstalling R and ROCR thanks for your help Heiko ______________________________________________ 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.