mars.learn.model_selection.train_test_split¶

mars.learn.model_selection.train_test_split(*arrays, **options)[源代码]¶

Split arrays or matrices into random train and test subsets

参数

*arrays (sequence of indexables with same length / shape[0]) – Allowed inputs are lists, numpy arrays, scipy-sparse matrices or pandas dataframes.
test_size (float, int or None, optional (default=None)) – If float, should be between 0.0 and 1.0 and represent the proportion of the dataset to include in the test split. If int, represents the absolute number of test samples. If None, the value is set to the complement of the train size. If train_size is also None, it will be set to 0.25.
train_size (float, int, or None, (default=None)) – If float, should be between 0.0 and 1.0 and represent the proportion of the dataset to include in the train split. If int, represents the absolute number of train samples. If None, the value is automatically set to the complement of the test size.
random_state (int, RandomState instance or None, optional (default=None)) – If int, random_state is the seed used by the random number generator; If RandomState instance, random_state is the random number generator; If None, the random number generator is the RandomState instance used by np.random.
shuffle (boolean, optional (default=True)) – Whether or not to shuffle the data before splitting. If shuffle=False then stratify must be None.
stratify (array-like or None (default=None)) – If not None, data is split in a stratified fashion, using this as the class labels.

返回

splitting – List containing train-test split of inputs.

返回类型

list, length=2 * len(arrays)

实际案例

>>> import mars.tensor as mt
>>> from mars.learn.model_selection import train_test_split
>>> X, y = mt.arange(10).reshape((5, 2)), range(5)
>>> X.execute()
array([[0, 1],
       [2, 3],
       [4, 5],
       [6, 7],
       [8, 9]])
>>> list(y)
[0, 1, 2, 3, 4]

>>> X_train, X_test, y_train, y_test = train_test_split(
...     X, y, test_size=0.33, random_state=42)
...
>>> X_train.execute()
array([[8, 9],
       [0, 1],
       [4, 5]])
>>> y_train.execute()
array([4, 0, 2])
>>> X_test.execute()
array([[2, 3],
       [6, 7]])
>>> y_test.execute()
array([1, 3])

>>> train_test_split(y, shuffle=False)
[array([0, 1, 2]), array([3, 4])]

mars.learn.model_selection.KFold

mars.learn.neighbors.NearestNeighbors