Question

我在python中创建了一个XGBoost分类器。我尝试<div class="item Others" data-cat="Others" data-path="/portfolio/others/jonasplatin_website/" data-gradient-1="#ffef80" data-gradient-2="#464646"> <div class="portfolio-wrapper"> <img src="/portfolio/others/jonasplatin_website/thumbnail.jpg" alt="Jonas Platin unofficial website" /> <div class="desc"> <h2 class="item-info">Jonas Platin unofficial website</h2> <h3 class="item-info">Webdesign</h3> </div> </div> </div>来找到像这样的最佳参数

GridSearch

运行搜索时出现错误

grid_search = GridSearchCV(model, param_grid, scoring="neg_log_loss", n_jobs=-1, cv=kfold)
grid_result = grid_search.fit(X, Y)

print("Best: %f using %s" % (grid_result.best_score_, grid_result.best_params_))

means = grid_result.cv_results_['mean_test_score']
stds = grid_result.cv_results_['std_test_score']
params = grid_result.cv_results_['params']

for mean, stdev, param in zip(means, stds, params):
    print("%f (%f) with: %r" % (mean, stdev, param))

我使用了一个略大的数据集。哪里， [Errno 28] No space left on device X.shape = (38932, 1002)

问题是什么？如何解决这个问题。？

这是因为数据集对我的机器来说太大了。如果是这样，我该怎么做才能在这个数据集上预先形成GridSearch。？

Answer 1

错误表明共享内存不足，可能增加 kfolds的数量和/或调整使用的线程数，即n_jobs将解决此问题。这是一个使用xgboost

的工作示例

import xgboost as xgb
from sklearn.model_selection import GridSearchCV
from sklearn import datasets

clf = xgb.XGBClassifier()
parameters = {
    'n_estimators': [100, 250, 500],
    'max_depth': [6, 9, 12],
    'subsample': [0.9, 1.0],
    'colsample_bytree': [0.9, 1.0],
}
bsn = datasets.load_iris()
X, Y = bsn.data, bsn.target
grid = GridSearchCV(clf,
                    parameters, n_jobs=4,
                    scoring="neg_log_loss",
                    cv=3)

grid.fit(X, Y)
print("Best: %f using %s" % (grid.best_score_, grid.best_params_))

means = grid.cv_results_['mean_test_score']
stds = grid.cv_results_['std_test_score']
params = grid.cv_results_['params']

for mean, stdev, param in zip(means, stds, params):
    print("%f (%f) with: %r" % (mean, stdev, param))

输出

Best: -0.121569 using {'colsample_bytree': 0.9, 'max_depth': 6, 'n_estimators': 100, 'subsample': 1.0}
-0.126334 (0.080193) with: {'colsample_bytree': 0.9, 'max_depth': 6, 'n_estimators': 100, 'subsample': 0.9}
-0.121569 (0.081561) with: {'colsample_bytree': 0.9, 'max_depth': 6, 'n_estimators': 100, 'subsample': 1.0}
-0.139359 (0.075462) with: {'colsample_bytree': 0.9, 'max_depth': 6, 'n_estimators': 250, 'subsample': 0.9}
-0.131887 (0.076174) with: {'colsample_bytree': 0.9, 'max_depth': 6, 'n_estimators': 250, 'subsample': 1.0}
-0.148302 (0.074890) with: {'colsample_bytree': 0.9, 'max_depth': 6, 'n_estimators': 500, 'subsample': 0.9}
-0.135973 (0.076167) with: {'colsample_bytree': 0.9, 'max_depth': 6, 'n_estimators': 500, 'subsample': 1.0}
-0.126334 (0.080193) with: {'colsample_bytree': 0.9, 'max_depth': 9, 'n_estimators': 100, 'subsample': 0.9}
-0.121569 (0.081561) with: {'colsample_bytree': 0.9, 'max_depth': 9, 'n_estimators': 100, 'subsample': 1.0}
-0.139359 (0.075462) with: {'colsample_bytree': 0.9, 'max_depth': 9, 'n_estimators': 250, 'subsample': 0.9}
-0.131887 (0.076174) with: {'colsample_bytree': 0.9, 'max_depth': 9, 'n_estimators': 250, 'subsample': 1.0}
-0.148302 (0.074890) with: {'colsample_bytree': 0.9, 'max_depth': 9, 'n_estimators': 500, 'subsample': 0.9}
-0.135973 (0.076167) with: {'colsample_bytree': 0.9, 'max_depth': 9, 'n_estimators': 500, 'subsample': 1.0}
-0.126334 (0.080193) with: {'colsample_bytree': 0.9, 'max_depth': 12, 'n_estimators': 100, 'subsample': 0.9}
-0.121569 (0.081561) with: {'colsample_bytree': 0.9, 'max_depth': 12, 'n_estimators': 100, 'subsample': 1.0}
-0.139359 (0.075462) with: {'colsample_bytree': 0.9, 'max_depth': 12, 'n_estimators': 250, 'subsample': 0.9}
-0.131887 (0.076174) with: {'colsample_bytree': 0.9, 'max_depth': 12, 'n_estimators': 250, 'subsample': 1.0}
-0.148302 (0.074890) with: {'colsample_bytree': 0.9, 'max_depth': 12, 'n_estimators': 500, 'subsample': 0.9}
-0.135973 (0.076167) with: {'colsample_bytree': 0.9, 'max_depth': 12, 'n_estimators': 500, 'subsample': 1.0}
-0.132745 (0.080433) with: {'colsample_bytree': 1.0, 'max_depth': 6, 'n_estimators': 100, 'subsample': 0.9}
-0.127030 (0.077692) with: {'colsample_bytree': 1.0, 'max_depth': 6, 'n_estimators': 100, 'subsample': 1.0}
-0.146143 (0.077623) with: {'colsample_bytree': 1.0, 'max_depth': 6, 'n_estimators': 250, 'subsample': 0.9}
-0.140400 (0.074645) with: {'colsample_bytree': 1.0, 'max_depth': 6, 'n_estimators': 250, 'subsample': 1.0}
-0.153624 (0.077594) with: {'colsample_bytree': 1.0, 'max_depth': 6, 'n_estimators': 500, 'subsample': 0.9}
-0.143833 (0.073645) with: {'colsample_bytree': 1.0, 'max_depth': 6, 'n_estimators': 500, 'subsample': 1.0}
-0.132745 (0.080433) with: {'colsample_bytree': 1.0, 'max_depth': 9, ...

XGBoost模型上的GridSearchCV给出了错误

1 个答案: