使用 Graphviz 绘制决策树时出现“特征名称长度与特征数量不匹配”错误

Question

我正在尝试使用 graphviz 可视化决策树，并在尝试绘制决策树时出现以下错误：

~\AppData\Local\Continuum\anaconda3\lib\site-packages\sklearn\tree\export.py in export_graphviz(decision_tree, out_file, max_depth, feature_names, class_names, label, filled, leaves_parallel, impurity, node_ids, proportion, rotate, rounded, special_characters, precision)
    427                                  "does not match number of features, %d"
    428                                  % (len(feature_names),
--> 429                                     decision_tree.n_features_))
    430 
    431         # The depth of each node for plotting with 'leaf' option

ValueError: Length of feature_names, 225 does not match number of features,

208

我的代码

dt=DecisionTreeClassifier(class_weight="balanced", min_samples_leaf=30)
fit_decision=dt.fit(X_train_res,y_train_res)
from graphviz import Source
from sklearn import tree
Source( tree.export_graphviz(fit_decision, out_file=None, feature_names=data.columns))

你能告诉我哪里出了问题吗？

Answer 1

您的 data.columns 包含所有特征的名称+标签，因为它不分为 X_train_res 和 y_train_res。您需要在 X_train_res 而不是 data.columns 中传递特征名称以获得确切的特征，否则它也会包含标签。在这种情况下，我假设 X_train 和 y_train 来自 data。

使用 Graphviz 绘制决策树时出现“特征名称长度与特征数量不匹配”错误

'Length of feature names doesn't match with number of features' error while plotting decision tree using Graphviz

graphviz

pandas

scikit-learn