pub fn roc_auc(scores: &[f64], labels: &[bool]) -> Option<f64>Expand description
ROC AUC via the Mann–Whitney rank statistic:
AUC = (R₊ − n₊(n₊+1)/2) / (n₊·n₋), where R₊ is the sum of the (tie-averaged)
ranks of the positive-class scores. Reuses the statistics ranker. None if the
inputs mismatch or a class is empty.