[R] obtaining a ROC curve

[Frank E Harrell Jr]

Anjali Karve wrote:
> Hello,
>   
>   I have a classification tree. I want to obtain a ROC curve for this test. What is the easiest way to obtain one?
>   
>   -Anjali

ROC curves have a number of problems, chief among them leading to the 
temptation of dichotomizing test results.  ROC areas are useful 
statistics though.  In the Hmisc package see somers2 and rcorr.cens for 
getting the ROC area nonparametrically.

Frank

-- 
Frank E Harrell Jr   Professor and Chair           School of Medicine
                      Department of Biostatistics   Vanderbilt University