sklearn决策树算法参数详解
1. 决策树分类器DecisionTreeClassifier
from sklearn.tree import DecisionTreeClassifier
# 创建ID3决策树
clf = DecisionTreeClassifier(criterion='entropy')
# 创建CART分类决策树
clf = DecisionTreeClassifier(criterion='gini')
DecisionTreeClassifier()的参数如下:
DecisionTreeClassifier(class_weight=None, criterion='entropy', max_depth=None,
max_features=None, max_leaf_nodes=None,
min_impurity_decrease=0.0, min_impurity_split=None,
min_samples_leaf=1, min_samples_split=2,
min_weight_fraction_leaf=0.0, presort=False, random_state=None,
splitter='best')
- class_weight:类别权重,默认为None。
可选值还有:dict,balanced;
dict:指定样本各类别的权重,权重大的类别在决策树构造的时候会进行偏倚;balanced:算法自己计算