class sklearn.model_selection.StratifiedKFold(n_splits=’warn’, shuffle=False, random_state=None)
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Stratified K-Folds cross-validator
Provides train/test indices to split data in train/test sets.
This cross-validation object is a variation of KFold that returns stratified folds. The folds are made by preserving the percentage of samples for each class.
Read more in the User Guide.
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See also
RepeatedStratifiedKFold
Train and test sizes may be different in each fold, with a difference of at most n_classes
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>>> from sklearn.model_selection import StratifiedKFold >>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]]) >>> y = np.array([0, 0, 1, 1]) >>> skf = StratifiedKFold(n_splits=2) >>> skf.get_n_splits(X, y) 2 >>> print(skf) StratifiedKFold(n_splits=2, random_state=None, shuffle=False) >>> for train_index, test_index in skf.split(X, y): ... print("TRAIN:", train_index, "TEST:", test_index) ... X_train, X_test = X[train_index], X[test_index] ... y_train, y_test = y[train_index], y[test_index] TRAIN: [1 3] TEST: [0 2] TRAIN: [0 2] TEST: [1 3]
get_n_splits ([X, y, groups]) | Returns the number of splitting iterations in the cross-validator |
split (X, y[, groups]) | Generate indices to split data into training and test set. |
__init__(n_splits=’warn’, shuffle=False, random_state=None)
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get_n_splits(X=None, y=None, groups=None)
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Returns the number of splitting iterations in the cross-validator
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Returns: |
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split(X, y, groups=None)
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Generate indices to split data into training and test set.
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Yields: |
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Randomized CV splitters may return different results for each call of split. You can make the results identical by setting random_state
to an integer.
sklearn.model_selection.StratifiedKFold
© 2007–2018 The scikit-learn developers
Licensed under the 3-clause BSD License.
http://scikit-learn.org/stable/modules/generated/sklearn.model_selection.StratifiedKFold.html