metrics._scorer.
时间: 2024-04-28 16:23:49 浏览: 36
`metrics._scorer.` 是一个 scikit-learn 库中的命名空间(namespace),用于包含各种性能指标的函数。命名空间是一种将函数和变量组织在一起的方式,可以避免名称冲突,并使代码更易于维护。在这个命名空间下,包含了很多常用的分类、回归、聚类等机器学习模型的性能指标函数,比如准确率(accuracy)、精确率(precision)、召回率(recall)、F1 分数(F1 score)等。通过调用这些函数,可以方便地评估机器学习模型的性能。
相关问题
Traceback (most recent call last): File "D:\python\lib\site-packages\sklearn\metrics\_scorer.py", line 430, in get_scorer scorer = copy.deepcopy(_SCORERS[scoring]) KeyError: 'mean_squared_error' During handling of the above exception, another exception occurred: Traceback (most recent call last): File "D:\tokamaka\实验集\Python\python利用支持向量机SVM进行时间序列预测(数据+源码)\demo.py", line 101, in <module> grid_search.fit(X_train,y_train) File "D:\python\lib\site-packages\sklearn\model_selection\_search.py", line 776, in fit scorers = check_scoring(self.estimator, self.scoring) File "D:\python\lib\site-packages\sklearn\metrics\_scorer.py", line 479, in check_scoring return get_scorer(scoring) File "D:\python\lib\site-packages\sklearn\metrics\_scorer.py", line 432, in get_scorer raise ValueError( ValueError: 'mean_squared_error' is not a valid scoring value. Use sklearn.metrics.get_scorer_names() to get valid options.
这个错误提示是因为`mean_squared_error`不是一个可用的评分指标,可以使用`sklearn.metrics.get_scorer_names()`函数获取可用的评分指标列表。如果您想使用`mean_squared_error`作为评分指标,可以使用`make_scorer`函数进行自定义。
示例代码如下:
```python
from sklearn.metrics import make_scorer, mean_squared_error
mse_scorer = make_scorer(mean_squared_error)
```
然后在`GridSearchCV`中将`scoring`参数设置为`mse_scorer`即可。
```python
grid_search = GridSearchCV(svm_reg, param_grid, cv=5, scoring=mse_scorer)
```
Traceback (most recent call last): File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\model_selection\_validation.py", line 761, in _score scores = scorer(estimator, X_test, y_test) File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\metrics\_scorer.py", line 103, in __call__ score = scorer._score(cached_call, estimator, *args, **kwargs) File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\metrics\_scorer.py", line 264, in _score return self._sign * self._score_func(y_true, y_pred, **self._kwargs) File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\metrics\_classification.py", line 1123, in f1_score return fbeta_score( File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\metrics\_classification.py", line 1261, in fbeta_score _, _, f, _ = precision_recall_fscore_support( File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\metrics\_classification.py", line 1544, in precision_recall_fscore_support labels = _check_set_wise_labels(y_true, y_pred, average, labels, pos_label) File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\metrics\_classification.py", line 1348, in _check_set_wise_labels y_type, y_true, y_pred = _check_targets(y_true, y_pred) File "D:\Program Files (x86)\Anaconda3-5.3.1\lib\site-packages\sklearn\metrics\_classification.py", line 93, in _check_targets raise ValueError( ValueError: Classification metrics can't handle a mix of multiclass and continuous targets
这个错误通常意味着你正在使用一个分类模型来预测连续型目标变量,或者你的目标变量是一个混合了多个类别和连续型值的数据集。
建议你检查一下你的目标变量的数据类型是否正确,并且确保你正在使用正确的模型来处理你的数据集。如果你的数据集中有连续型的目标变量,你可以考虑使用回归模型来预测它们。如果你的数据集中有多个类别的目标变量,你可以使用分类模型来预测它们,但要注意分类模型的输出格式。
阅读全文