我有一个名为svc_param_selection(X, y, n)
的函数,它返回best_param_
。现在我想将返回的最佳参数用作分类器的参数,如下所示:
parameters = svc_param_selection(X, y, 2)from sklearn.model_selection import ParameterGridfrom sklearn.svm import SVCparam_grid = ParameterGrid(parameters)for params in param_grid: svc_clf = SVC(**params) print (svc_clf)classifier2=SVC(**svc_clf)
这里的parameters似乎不是一个网格..
回答:
您可以使用GridSearchCV来实现这一点。这里有一个例子:
# 应用GridSearch来寻找最佳参数from sklearn.model_selection import GridSearchCVparameters = [{ 'criterion' : ['gini'], 'splitter':['best','random'], 'min_samples_split':[0.1,0.2,0.3,0.4,0.5], 'min_samples_leaf': [1,2,3,4,5]}, {'criterion' : ['entropy'], 'splitter':['best','random'], 'min_samples_split':[0.1,0.2,0.3,0.4,0.5], 'min_samples_leaf': [1,2,3,4,5]} ]gridsearch = GridSearchCV(estimator = classifier, param_grid = parameters,refit= False, scoring='accuracy', cv=10)gridsearch = gridsearch.fit(x,y)optimal_accuracy = gridsearch.best_score_optimal_parameters = gridsearch.best_params_
但是,对于GridSearchCV
的param_grid
,您应该传递一个包含分类器参数名称和值的字典。例如,像这样的分类器:
from sklearn.tree import DecisionTreeClassifierclassifier = DecisionTreeClassifier(random_state=0, presort=True, criterion='entropy')classifier = classifier.fit(x_train,y_train)
然后,在通过GridSearchCV
找到最佳参数后,您可以将它们应用到您的模型上。