ROC (Receiver Operating Characteristics) Curve in R

There are 2 packages to calculate different measures and draw different graphs of ROC cureve.

1. ROCR (http://rocr.bioinf.mpi-sb.mpg.de/)
2. pROC (http://cran.r-project.org/web/packages/pROC/pROC.pdf)

Code to generate ROC curve and AUC (Area under the curve) value

Using ROCR:

 # generate ROC curve  
 pred <- prediction(scores, labels)  
 perf <- performance(pred, "tpr", "fpr")  
 plot(perf)  

 #calculate AUC value  
 aucPerf <- performance( pred, 'auc')  
 auc <- slot(aucPerf, "y.values")  

Using pROC:

 roc.obj <- roc(response=labels, predictor=scores)  
 plot(roc.obj)  
 auc(roc.obj)