sklearn validation_curve 中的默认评分函数是什么?

What's the default score function in validation_curve in sklearn?

我是运行下面这行代码:

validation_curve(PolynomialRegression(),X,y,
                 param_name='polynomialfeatures__degree',
                 param_range=degree,cv=7)

而且,当我画 validation_curve 时,我得到的更高学位的分数非常低。当我检查 documentation 时,它显示

scoring:str or callable, default=None A str (see model evaluation documentation) or a scorer callable object / function with signature scorer(estimator, X, y).

我只是想知道 sklearn validation_curve 中的默认评分函数是什么?如果是 None,那么他们如何计算分数?

它默认为估计器的 score 方法,而后者通常是准确性(分类)或 R2(回归)。

source for validation_curve, it calls check_scorer, which in part contains中:

    elif scoring is None:
        if hasattr(estimator, 'score'):
            return _passthrough_scorer

其中 _passthrough_scorer just wraps 估算器的 score:

def _passthrough_scorer(estimator, *args, **kwargs):
    """Function that wraps estimator.score"""
    return estimator.score(*args, **kwargs)