我试图用GridSearchCV和管道建立一个多输出模型。 Pipeline给我带来麻烦,因为标准分类器示例没有包装分类器的OneVsRestClassifier()。我使用scikit学习0.18和3.5蟒Scikit学习多输出分类器使用:GridSearchCV,管道,OneVsRestClassifier,SGDClassifier
## Pipeline: Train and Predict
## SGD: support vector machine (SVM) with gradient descent
from sklearn.multiclass import OneVsRestClassifier
from sklearn.pipeline import Pipeline
from sklearn.linear_model import SGDClassifier
clf = Pipeline([
('vect', CountVectorizer(ngram_range=(1,3), max_df=0.50)),
('tfidf', TfidfTransformer()),
('clf', SGDClassifier(loss='modified_huber', penalty='elasticnet',
alpha=1e-4, n_iter=5, random_state=42,
shuffle=True, n_jobs=-1)),
])
ovr_clf = OneVsRestClassifier(clf)
from sklearn.model_selection import GridSearchCV
parameters = {'vect__ngram_range': [(1,1), (1,3)],
'tfidf__norm': ('l1', 'l2', None),
'estimator__loss': ('modified_huber', 'hinge',),
}
gs_clf = GridSearchCV(estimator=pipeline, param_grid=parameters,
scoring='f1_weighted', n_jobs=-1, verbose=1)
gs_clf = gs_clf.fit(X_train, y_train)
但是,这产生了错误: ....
ValueError: Invalid parameter estimator for estimator Pipeline(steps=[('vect', CountVectorizer(analyzer='word', binary=False, decode_error='strict', dtype=, encoding='utf-8', input='content', lowercase=True, max_df=0.5, max_features=None, min_df=1, ngram_range=(1, 3), preprocessor=None, stop_words=None, strip...er_t=0.5, random_state=42, shuffle=True, verbose=0, warm_start=False), n_jobs=-1))]). Check the list of available parameters with
estimator.get_params().keys()
.
那么,什么是传递参数通过OneVsRestClassifier到CLF的正确方法使用param_grid和Pipeline?我是否需要将流水线中的分类器和tdidf分开?
工作! (1)我移动管道内的OneVsRestClassifier以包装SGDClassifier。 (2)我将前缀'clf__'添加到param_grid处理估计器参数中,即'clf__estimator__penalty'。 – MyopicVisage