Table 2 Formulas used to calculate Model Validation metrics

tpr (true positive rate)

$tpr=\frac{TP}{POS}$

fpr (false positive rate)

$fpr=\frac{FP}{NEG}$

rfp (relative frequency of positives)

$rfp=\frac{POS}{\left(POS+NEG\right)}$

C (class ratio or skew ratio)

$c=\frac{NEG}{POS}$

sk_acc (accuracy)

$sk\_acc=tpr+c\frac{\left(\text{1}-fpr\right)}{\text{1}}+c$

sk_prec (precision)

$sk\_prec=\frac{tpr}{tpr+c\cdot fpr}$