Hi,
I am quite new to R and I have two questions regarding ROCR.

1. I have tried to understand how to extract area-under-curve value by looking at the ROCR document and googling. Still I am not sure if I am doing the right thing. Here is my code, is "auc1" the auc value?
"
pred1 <- prediction(resp1,label1)

perf1 <- performance(pred1,"tpr","fpr")
plot( perf1, type="l",col=1 )

auc1 <- performance(pred1,"auc")
auc1 <- auc1@y.values[[2]]
"

2. I have to compare two models that have very close ROCs. I'd like to have a more distinguishable plot of the ROCs. So is it possible to have a logarithm FP axis which might probably separate them well? Or zoom in the part close to the leftup corner of ROC plot? Or any other ways to make the ROCs more separate?

Thanks and regards!

--Tim



      
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