# 不均衡样本时的评价

在二分类问题中，当测试集的正例和负例数量不均衡时，以下评价方案哪个是相对不合理的（A）

（假设 precision=TP/(TP+FP),recall=TP/(TP+FN)。）

* A. Accuracy:(TP+TN)/all
* B.F-value:2*recall*precision/(recall+precision)
* C.G-mean:sqrt(precision\*recall)
* D.AUC:曲线下面积

<https://www.nowcoder.com/questionTerminal/4010d9eba4574364a130af401c1c31ea?orderByHotValue=0&pos=2&mutiTagIds=630>


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