将随机森林、SVM、逻辑回归、Bagging、XG-Boost五种分类器分别进行随机搜索优化后再分别jinxing两两、三三、四四、五五排列组合用作集成分类(二分类)的python代码 同时输出对应组合的分类器具体是那几个分类器
时间: 2023-12-02 17:03:01 浏览: 196
以下是对应的Python代码:
```python
from sklearn.ensemble import RandomForestClassifier, BaggingClassifier, VotingClassifier
from sklearn.svm import SVC
from sklearn.linear_model import LogisticRegression
from xgboost import XGBClassifier
from sklearn.model_selection import RandomizedSearchCV
from sklearn.metrics import accuracy_score
from itertools import combinations
# 定义五种分类器
rfc = RandomForestClassifier()
svc = SVC()
lr = LogisticRegression()
bc = BaggingClassifier()
xgb = XGBClassifier()
# 定义每个分类器需要调整的参数范围
rfc_params = {
'n_estimators': [10, 50, 100, 200, 500],
'max_depth': [2, 5, 10, 20, 50, None],
'min_samples_split': [2, 5, 10, 20],
'min_samples_leaf': [1, 2, 4, 8]
}
svc_params = {
'C': [0.1, 1, 10],
'kernel': ['linear', 'rbf', 'poly'],
'degree': [2, 3, 4],
'gamma': ['scale', 'auto']
}
lr_params = {
'C': [0.1, 1, 10],
'solver': ['newton-cg', 'lbfgs', 'liblinear', 'sag', 'saga'],
'penalty': ['l1', 'l2', 'elasticnet', 'none'],
'max_iter': [100, 200, 500]
}
bc_params = {
'base_estimator__max_depth': [2, 5, 10, 20, 50, None],
'base_estimator__min_samples_split': [2, 5, 10, 20],
'base_estimator__min_samples_leaf': [1, 2, 4, 8],
'n_estimators': [10, 50, 100, 200, 500]
}
xgb_params = {
'learning_rate': [0.01, 0.1, 0.5],
'max_depth': [2, 5, 10, 20],
'min_child_weight': [1, 2, 4, 8],
'subsample': [0.5, 0.8, 1],
'colsample_bytree': [0.5, 0.8, 1],
'n_estimators': [10, 50, 100, 200, 500]
}
# 定义需要进行优化的分类器
classifiers = [
{'name': 'Random Forest', 'clf': rfc, 'params': rfc_params},
{'name': 'SVM', 'clf': svc, 'params': svc_params},
{'name': 'Logistic Regression', 'clf': lr, 'params': lr_params},
{'name': 'Bagging', 'clf': bc, 'params': bc_params},
{'name': 'XGBoost', 'clf': xgb, 'params': xgb_params}
]
# 对每个分类器进行随机搜索优化
for clf in classifiers:
print('Optimizing {} ...'.format(clf['name']))
rand_search = RandomizedSearchCV(clf['clf'], clf['params'], n_iter=20, cv=5, n_jobs=-1)
rand_search.fit(X_train, y_train)
clf['best_clf'] = rand_search.best_estimator_
clf['best_params'] = rand_search.best_params_
print('Best parameters: {}'.format(clf['best_params']))
print('Training accuracy: {}'.format(accuracy_score(y_train, clf['best_clf'].predict(X_train))))
print('Validation accuracy: {}'.format(accuracy_score(y_val, clf['best_clf'].predict(X_val))))
print()
# 将分类器进行两两、三三、四四、五五排列组合
combinations_list = []
for i in range(2, 6):
combinations_list.extend(list(combinations(classifiers, i)))
# 定义用于存储每种组合的分类器名称的列表
classifier_names = []
# 对每种组合进行集成分类
for combination in combinations_list:
clf_names = [clf['name'] for clf in combination]
classifier_names.append(clf_names)
print('Using classifiers: {}'.format(clf_names))
voting_clf = VotingClassifier([(clf['name'], clf['best_clf']) for clf in combination], voting='hard')
voting_clf.fit(X_train, y_train)
print('Training accuracy: {}'.format(accuracy_score(y_train, voting_clf.predict(X_train))))
print('Validation accuracy: {}'.format(accuracy_score(y_val, voting_clf.predict(X_val))))
print()
```
输出结果中,每种组合的分类器名称都会被打印出来,例如:
```
Using classifiers: ['Random Forest', 'SVM']
Training accuracy: 0.999
Validation accuracy: 0.958
Using classifiers: ['Random Forest', 'SVM', 'Logistic Regression']
Training accuracy: 1.0
Validation accuracy: 0.958
Using classifiers: ['Random Forest', 'SVM', 'Logistic Regression', 'Bagging']
Training accuracy: 0.998
Validation accuracy: 0.963
Using classifiers: ['Random Forest', 'SVM', 'Logistic Regression', 'Bagging', 'XGBoost']
Training accuracy: 0.999
Validation accuracy: 0.965
```
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