# How to compute a weighted AUC?

Say that I have a set of training examples with binary 0-1 labels, and corresponding regression labels ranging from 0 to 1. Normally, to compute AUC I've used the ROCR package in R, which also allows me to compute the optimal cutoff point. In addition to these labels and predictions, I also have a weight column which ranges from 0 to 1 and signifies the importance of each example. I was wondering how I could compute the AUC and optimal cutoff point of these examples, taking these weights into account.