roc function

roc

Internal use only. Adapted from Ferrier, Pearce and Watson's code, by J.Elith , see: Hanley, J.A. & McNeil, B.J. (1982) The meaning and use of the area under a Receiver Operating Characteristic (ROC) curve. Radiology, 143, 29-36. Also Pearce, J. & Ferrier, S. (2000) Evaluating the predictive performance of habitat models developed using logistic regression. Ecological Modelling, 133, 225-245. This is the non-parametric calculation for area under the ROC curve, using the fact that a MannWhitney U statistic is closely related to the area. In dismo, this is used in the gbm routines, but not elsewhere (see evaluate).

roc(obsdat, preddat)

Arguments

• obsdat: Observed data.
• preddat: Predicted data.

Returns

roc & calibration stats internally within gbm runs e.g. in gbm.auto.

Examples

roc(obsdat = rbinom(100,size = 1, prob = 0.5), preddat = runif(100))

Author(s)

Simon Dedman, simondedman@gmail.com