Name	Expression	Description
True Positive Rate	$T P R = \frac{T P}{F N + T P}$	Also called sensitivity or recall: is the proportion of actual positives that are correctly identified as a positive class.
True Negative Rate	$T N R = \frac{T N}{T N + F P}$	Also called specificity: is the proportion of actual negatives that are correctly identified as a negative class.
Accuracy	$A = \frac{T P + T N}{T N + F P + F N + T P}$	Is the proportion of correct predictions in the total observations.
Precision	$P = \frac{T P}{F P + T P}$	is the proportion of predicted positives that are actually a positive class.
F1 score	$F 1 = 2 \frac{P \times T P R}{P + T P R}$	Is the harmonic means of the precision and recall (TPR) and can be used as a single measure of the test performance for the positive class.