sklearn.model_selection.RepeatedStratifiedKFold — scikit-learn 0.20.4 documentation (original) (raw)

class sklearn.model_selection. RepeatedStratifiedKFold(n_splits=5, n_repeats=10, random_state=None)[source]

Repeated Stratified K-Fold cross validator.

Repeats Stratified K-Fold n times with different randomization in each repetition.

Read more in the User Guide.

Parameters: n_splits : int, default=5 Number of folds. Must be at least 2. n_repeats : int, default=10 Number of times cross-validator needs to be repeated. random_state : None, int or RandomState, default=None Random state to be used to generate random state for each repetition.

Notes

Randomized CV splitters may return different results for each call of split. You can make the results identical by setting random_stateto an integer.

Examples

from sklearn.model_selection import RepeatedStratifiedKFold X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]]) y = np.array([0, 0, 1, 1]) rskf = RepeatedStratifiedKFold(n_splits=2, n_repeats=2, ... random_state=36851234) for train_index, test_index in rskf.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 2] TEST: [0 3] TRAIN: [0 3] TEST: [1 2] TRAIN: [1 3] TEST: [0 2] TRAIN: [0 2] TEST: [1 3]

Methods

get_n_splits([X, y, groups]) Returns the number of splitting iterations in the cross-validator
split(X[, y, groups]) Generates indices to split data into training and test set.

__init__(n_splits=5, n_repeats=10, random_state=None)[source]

get_n_splits(X=None, y=None, groups=None)[source]

Returns the number of splitting iterations in the cross-validator

Parameters: X : object Always ignored, exists for compatibility.np.zeros(n_samples) may be used as a placeholder. y : object Always ignored, exists for compatibility.np.zeros(n_samples) may be used as a placeholder. groups : array-like, with shape (n_samples,), optional Group labels for the samples used while splitting the dataset into train/test set.
Returns: n_splits : int Returns the number of splitting iterations in the cross-validator.

split(X, y=None, groups=None)[source]

Generates indices to split data into training and test set.

Parameters: X : array-like, shape (n_samples, n_features) Training data, where n_samples is the number of samples and n_features is the number of features. y : array-like, of length n_samples The target variable for supervised learning problems. groups : array-like, with shape (n_samples,), optional Group labels for the samples used while splitting the dataset into train/test set.
Yields: train : ndarray The training set indices for that split. test : ndarray The testing set indices for that split.