Hi There, I don't understand how to order the label in ROCR package in order to get the correct result. I am wondering whether you can help me.
library(ROCR) data(ROCR.simple) pred <- prediction(ROCR.simple$predictions,ROCR.simple$labels) svm.auc <- performance(pred, 'tpr', 'fpr') plot(svm.auc) #####label ROCR.simple$labels[ROCR.simple$labels=="0"]="tumor" ROCR.simple$labels[ROCR.simple$labels==1]="normal" pred <- prediction(ROCR.simple$predictions,ROCR.simple$labels) svm.auc <- performance(pred, 'tpr', 'fpr') plot(svm.auc) The ROC curve is fliped. How do we know which order of labels we should choose? Is this a bug of ROC? thank you very much. Mike ______________________________________________ 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.
