The column ratios are TRUE Positive Rate ( TPR , aka Sensitivity or recall ) ( TP / ( TP + FN ) ) , with complement the FALSE Negative Rate ( FNR ) ( FN / ( TP + FN ) ) ; and TRUE Negative Rate ( TNR , aka Specificity , SPC ) ( TN / ( TN + FP ) ) , with complement FALSE Positive Rate ( FPR ) ( FP / ( TN + FP ) ) .