在随机森林中,predict() 和predict_proba() 都给出了不同的roc_auc_score。
据我所知,predict_proba() 给出了概率,例如在二元分类的情况下,它将给出对应于两个类的两个概率。Predict() 给出了它预测的类。
#Using predict_proba()
rf = RandomForestClassifier(n_estimators=200, random_state=39)
rf.fit(X_train[['Cabin_mapped', 'Sex']], y_train)
#make predictions on train and test set
pred_train = rf.predict_proba(X_train[['Cabin_mapped', 'Sex']])
pred_test = rf.predict_proba(X_test[['Cabin_mapped', 'Sex']].fillna(0))
print('Train set')
print('Random Forests using predict roc-auc: {}'.format(roc_auc_score (y_train, pred_train)))
print('Test set')
print('Random Forests using predict roc-auc: {}'.format(roc_auc_score(y_test, pred_test)))
#using predict()
pred_train = rf.predict(X_train[['Cabin_reduced', 'Sex']])
pred_test = rf.predict(X_test[['Cabin_reduced', 'Sex']])
print('Train set')
print('Random Forests using predict roc-auc: {}'.format(roc_auc_score(y_train, pred_train)))
print('Test set')
print('Random Forests using predict roc-auc: {}'.format(roc_auc_score(y_test, pred_test)))
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使用 Predict_proba roc-auc …