It is common in the literature to define various combinations the above numbers. The most commonly used are
The \( TPR \) defines how many correct positive results occur among all positive samples available during the test
with the fall-out false positive rate
$$ {\displaystyle \mathrm {FPR} ={\frac {\mathrm {FP} }{\mathrm {N} }}={\frac {\mathrm {FP} }{\mathrm {FP} +\mathrm {TN} }}=1-\mathrm {TNR} } $$The \( FPR \) defines how many incorrect positive results occur among all negative samples available during the test.