auc: Calculate AUC
In BioStaCs/BSCgas: Greedy AUC stepwise

Description Usage Arguments Details Value Author(s) References Examples

Calculate AUC with or without missing

1	auc(pred, lable, draw = F, option = "all")

`pred`	prediction results (real value)
`lable`	target value (binary)
`draw`	If TRUE, then draw a ROC curve
`option`	Missing Value handling

This function is a wrapper of ROCR

return value is area under curve.

Yifan Yang

ROCR

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function (pred, lable, draw = F, option = "all") 
{
    if (option == "all") {
        pred.roc <- prediction(pred, lable)
        perf <- performance(pred.roc, "tpr", "fpr")
        if (draw) 
            plot(perf, col = 2, main = "GLM")
        perf.auc <- performance(pred.roc, "auc")
        perf.auc.areas <- slot(perf.auc, "y.values")
        curve.area <- mean(unlist(perf.auc.areas))
    }
    else {
        nomissing <- !is.na(lable)
        pred <- pred[nomissing]
        lable <- lable[nomissing]
        pred.roc <- prediction(pred, lable)
        perf <- performance(pred.roc, "tpr", "fpr")
        if (draw) 
            plot(perf, col = 2, main = "GLM")
        perf.auc <- performance(pred.roc, "auc")
        perf.auc.areas <- slot(perf.auc, "y.values")
        curve.area <- mean(unlist(perf.auc.areas))
    }
    return(curve.area)
  }