Hi, I've used the ROC function from the Epi package to plot an ROC curve and generate descriptive statistics (i.e. sensitivity, specificity, PPV, NPV) for what ROC considers the best predictor score - this is done automatically by ROC on the graph. What I want to do, is get these same descriptives for other predictor scores.
Here is the code I've used: ROC(stat=diseaseStatus, test=screenScore, cuts=c(3,4,6), PV=T) This prints out the ROC curve. From prior exploration I know that ROC identifies screenScore=5 as the "best" predictor score (sens=91.7%, spec=88.9%, PPV=0.2%, NPV = 82.5%, I have a very low base rate disease). When I use the "cuts" option, ROC adds those values to the graph (3.00, 4.00, 6.00) but does not print the descriptives for those predictor values. I don't necessarily want them on the graph, I'm happy to just have the descriptives for '5' on there, but I want to have access to the descriptives for other values to build a typical table that presents the quantitative comparison of values. I haven't been able to figure out how to get access to those values. Also, I have seen there are several packages capable of computing ROC stats, but I haven't found what I want from any of them. I'm happy to use another one if that is what you are familiar with. Thanks -- View this message in context: http://r.789695.n4.nabble.com/Extracting-information-from-ROC-tp4689693.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.
