請參考筆記本以下地址錯誤scikit.learn cross_val_score
的代碼這一部分,
scores = cross_val_score(LogisticRegression(), X, y, scoring='accuracy', cv=10)
print scores
print scores.mean()
在窗口7的64位機器
生成以下錯誤---------------------------------------------------------------------------
IndexError Traceback (most recent call last)
<ipython-input-37-4a10affe67c7> in <module>()
1 # evaluate the model using 10-fold cross-validation
----> 2 scores = cross_val_score(LogisticRegression(), X, y, scoring='accuracy', cv=10)
3 print scores
4 print scores.mean()
C:\Python27\lib\site-packages\sklearn\cross_validation.pyc in cross_val_score(estimator, X, y, scoring, cv, n_jobs, verbose, fit_params, score_func, pre_dispatch)
1140 allow_nans=True, allow_nd=True)
1141
-> 1142 cv = _check_cv(cv, X, y, classifier=is_classifier(estimator))
1143 scorer = check_scoring(estimator, score_func=score_func, scoring=scoring)
1144 # We clone the estimator to make sure that all the folds are
C:\Python27\lib\site-packages\sklearn\cross_validation.pyc in _check_cv(cv, X, y, classifier, warn_mask)
1366 if classifier:
1367 if type_of_target(y) in ['binary', 'multiclass']:
-> 1368 cv = StratifiedKFold(y, cv, indices=needs_indices)
1369 else:
1370 cv = KFold(_num_samples(y), cv, indices=needs_indices)
C:\Python27\lib\site-packages\sklearn\cross_validation.pyc in __init__(self, y, n_folds, indices, shuffle, random_state)
428 for test_fold_idx, per_label_splits in enumerate(zip(*per_label_cvs)):
429 for label, (_, test_split) in zip(unique_labels, per_label_splits):
--> 430 label_test_folds = test_folds[y == label]
431 # the test split can be too big because we used
432 # KFold(max(c, self.n_folds), self.n_folds) instead of
IndexError: too many indices for array
我正在使用scikit.learn 0.15.2,這是建議d here這可能是windows 7,64位機器的一個特定問題。
============== ==============更新
我發現下面的代碼實際工作
from sklearn.cross_validation import KFold
cv = KFold(X.shape[0], 10, shuffle=True, random_state=33)
scores = cross_val_score(LogisticRegression(), X, y, scoring='accuracy', cv=cv)
print scores
==============更新2 =============
它似乎由於一些包更新,我不能再重現這樣的錯誤我的機器。如果您在Windows 7 64位計算機上遇到同樣的問題,請告訴我。
'y'的形狀是什麼? – 2014-10-22 12:01:34
@larsmans(6366L,) – tesla1060 2014-10-22 14:36:18
什麼可行,什麼不行的唯一區別是'cv'? 'X.shape [0] == 6366'也? – eickenberg 2014-10-22 14:37:44