如何计算两个嵌套数组的精度和召回率

时间:2018-04-24 09:11:14

标签: python machine-learning scikit-learn precision precision-recall

我有两个数组:

correct = [['*','*'],['*','PER','*','GPE','ORG'],['GPE','*','*','*','ORG']]
predicted = [['PER','*'],['*','ORG','*','GPE','ORG'],['PER','*','*','*','MISC']]

正确和预测的长度相同(10K +)两个阵列中每个位置元素的长度也具有相同的长度。 我想用python计算这两个数组的精度,召回率和f1分数。 我有以下6个班级:   ' PER'' ORG'' MISC'' LOC'' *',' GPE'

想要计算5个班级的精确度和召回率(除了' *')也要找到f1得分。 什么是使用python执行此操作的有效方法?

1 个答案:

答案 0 :(得分:1)

您必须按照here展示您的列表,然后使用scikit-learn中的classification_report

correct = [['*','*'],['*','PER','*','GPE','ORG'],['GPE','*','*','*','ORG']]
predicted = [['PER','*'],['*','ORG','*','GPE','ORG'],['PER','*','*','*','MISC']]
target_names = ['PER','ORG','MISC','LOC','GPE'] # leave out '*'

correct_flat = [item for sublist in correct for item in sublist]
predicted_flat = [item for sublist in predicted for item in sublist]

from sklearn.metrics import classification_report
print(classification_report(correct_flat, predicted_flat, target_names=target_names))

结果:

             precision    recall  f1-score   support

        PER       1.00      0.86      0.92         7
        ORG       1.00      0.50      0.67         2
       MISC       0.00      0.00      0.00         0
        LOC       0.50      0.50      0.50         2
        GPE       0.00      0.00      0.00         1

avg / total       0.83      0.67      0.73        12

在此特定示例中,您还会收到警告:

UndefinedMetricWarning: Recall and F-score are ill-defined and being set to 0.0 in labels with no true samples.

这是由于'MISC'不存在于此处的真实标签中(correct),但可以说这不应该发生在您的真实数据中。