Python 如何处理多类决策树?

Python 如何处理多类决策树?,python,machine-learning,decision-tree,sklearn-pandas,gridsearchcv,Python,Machine Learning,Decision Tree,Sklearn Pandas,Gridsearchcv,我对python&ML不熟悉,但我正在尝试使用sklearn构建决策树。我有很多分类特征,我把它们转换成了数值变量。然而,我的目标功能是一个多类,我遇到了一个错误。我应该如何处理多类目标 ValueError:目标为多类,但average='binary'。请选择另一个平均值设置,即[无、'微'、'宏'、'加权']中的一个 from sklearn.model_selection import train_test_split #SPLIT DATA INTO TRAIN AND TEST S

我对python&ML不熟悉,但我正在尝试使用sklearn构建决策树。我有很多分类特征,我把它们转换成了数值变量。然而,我的目标功能是一个多类,我遇到了一个错误。我应该如何处理多类目标

ValueError:目标为多类,但average='binary'。请选择另一个平均值设置,即[无、'微'、'宏'、'加权']中的一个

from sklearn.model_selection import train_test_split

#SPLIT DATA INTO TRAIN AND TEST SET
X_train, X_test, y_train, y_test = train_test_split(X, y, 
                                                    test_size =0.30, #by default is 75%-25%
                                                    #shuffle is set True by default,
                                                    stratify=y, #preserve target propotions 
                                                    random_state= 123) #fix random seed for replicability

print(X_train.shape, X_test.shape)


from sklearn.tree import DecisionTreeClassifier
model = DecisionTreeClassifier(criterion='gini', max_depth=3, min_samples_split=4, min_samples_leaf=2)

model.fit(X_train, y_train)
y_pred = model.predict(X_test)

# criterion : "gini", "entropy"
# max_depth : The maximum depth of the tree.
# min_samples_split : The minimum number of samples required to split an internal node:
# min_samples_leaf : The minimum number of samples required to be at a leaf node. 

#DEFINE YOUR CLASSIFIER and THE PARAMETERS GRID
from sklearn.tree import DecisionTreeClassifier
import numpy as np

classifier = DecisionTreeClassifier()
parameters = {'criterion': ['entropy','gini'], 
              'max_depth': [3,4,5],
              'min_samples_split': [5,10],
              'min_samples_leaf': [2]}

from sklearn.model_selection import GridSearchCV
gs = GridSearchCV(classifier, parameters, cv=3, scoring = 'f1', verbose=50, n_jobs=-1, refit=True)

您应该手动指定分数函数:

from sklearn.metrics import f1_score, make_scorer

f1 = make_scorer(f1_score, average='weighted')

....

gs = GridSearchCV(classifier, parameters, cv=3, scoring=f1, verbose=50, n_jobs=-1, refit=True)

非常感谢你的帮助。我想出来了。实际上是在gs线上。在得分方面,我需要调整你提到的内容。所以我修改了评分=f1\U宏

gs = GridSearchCV(classifier, parameters, cv=3, scoring=f1_macro, verbose=50, n_jobs=-1, refit=True)

谢谢你的建议,我刚刚尝试了一下,也遇到了同样的错误。我刚刚调整了我的代码示例。你能试试吗?不客气!如果能把答案作为解决办法,我将不胜感激。