我使用带有BaggingClassifier的决策桩对某些数据进行分类:
def fit_ensemble(attributes,class_val,n_estimators):
# max depth is 1
decisionStump = DecisionTreeClassifier(criterion = 'entropy', max_depth = 1)
ensemble = BaggingClassifier(base_estimator = decisionStump, n_estimators = n_estimators, verbose = 3)
return ensemble.fit(attributes,class_val)
def predict_all(fitted_classifier, instances):
for i, instance in enumerate(instances):
instances[i] = fitted_classifier.predict([instances[i]])
return list(itertools.chain(*instances))
def main(filename, n_estimators):
df_ = read_csv(filename)
col_names = df_.columns.values.tolist()
attributes = col_names[0:-1] ## 0..n-1
class_val = col_names[-1] ## n
fitted = fit_ensemble(df_[attributes].values, df_[class_val].values, n_estimators)
fitted_classifiers = fitted.estimators_ # get the three decision stumps.
compared_ = DataFrame(index = range(0,len(df_.index)), columns = range(0,n_estimators + 1))
compared_ = compared_.fillna(0)
compared_.ix[:,n_estimators] = df_[class_val].values
for i, fitted_classifier in enumerate(fitted_classifiers):
compared_.ix[:,i] = predict_all(fitted_classifier,df_[attributes].values)我想检查用于训练每个决策树桩的随机子集。我看过集成类和决策树类的文档,但没有找到任何属性或方法来生成训练子集。这是一个徒劳无功的任务吗?或者,在树进行训练时,是否有某种方式输出训练子集?
我对熊猫很陌生,但来自R的背景。我的代码绝对不是优化的,尽管我可以保证数据集对于我的任务非常小。谢谢你的帮助。
发布于 2015-05-15 17:35:29
看来我已经回答了我自己的问题。estimators_samples_属性DecisionTreeClassifier是我想要的。
https://stackoverflow.com/questions/30265285
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