sklearn.model_selection.PredefinedSplit¶
- class sklearn.model_selection.PredefinedSplit(test_fold)[source]¶
Predefined split cross-validator
Provides train/test indices to split data into train/test sets using a predefined scheme specified by the user with the test_fold parameter.
Read more in the User Guide.
Parameters: test_fold : array-like, shape (n_samples,)
The entry test_fold[i] represents the index of the test set that sample i belongs to. It is possible to exclude sample i from any test set (i.e. include sample i in every training set) by setting test_fold[i] equal to -1.
Examples
>>> from sklearn.model_selection import PredefinedSplit >>> X = np.array([[1, 2], [3, 4], [1, 2], [3, 4]]) >>> y = np.array([0, 0, 1, 1]) >>> test_fold = [0, 1, -1, 1] >>> ps = PredefinedSplit(test_fold) >>> ps.get_n_splits() 2 >>> print(ps) PredefinedSplit(test_fold=array([ 0, 1, -1, 1])) >>> for train_index, test_index in ps.split(): ... 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 3] TEST: [0] 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]) Generate indices to split data into training and test set. - 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.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns: n_splits : int
Returns the number of splitting iterations in the cross-validator.
- split(X=None, y=None, groups=None)[source]¶
Generate indices to split data into training and test set.
Parameters: X : object
Always ignored, exists for compatibility.
y : object
Always ignored, exists for compatibility.
groups : object
Always ignored, exists for compatibility.
Returns: train : ndarray
The training set indices for that split.
test : ndarray
The testing set indices for that split.