Hi everybody, Pascal, your script works again but I want to calculate the LR otherwise. I know the likelihood ratio is linked at the roc curve and so there are different ways to calculate the LR. The slope of an ROC curve can be defined in three ways: (1) as the tangent at a particular point on the ROC curve corresponding to a test value x (2) as the slope between the origin 0 and the point on the ROC curve corresponding to a test value x (3) as the slope between two points on the ROC curve corresponding to the test values x and y
http://r.789695.n4.nabble.com/file/n4478233/LR.png But in my case, I want calculated the LR with the third way. So, LR (x,y) =(sensitivity (x)-sensitivity (y))/(specificity (y)-specificity (x)) = (TPR(x)-TPR (y))/(FPR (x)-FPR (y)) It is possible ?! All the best, Camille ----- -- Camille Leclerc, Master student Lab ESE, UMR CNRS 8079 Univ Paris-Sud Bat 362 F-91405 Orsay Cedex FRANCE -- View this message in context: http://r.789695.n4.nabble.com/ROC-Analysis-tp4469203p4478233.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.