numpy.stack — NumPy v1.13 Manual (original) (raw)
numpy. stack(arrays, axis=0)[source]¶
Join a sequence of arrays along a new axis.
The axis parameter specifies the index of the new axis in the dimensions of the result. For example, if axis=0 it will be the first dimension and if axis=-1 it will be the last dimension.
New in version 1.10.0.
| Parameters: | arrays : sequence of array_like Each array must have the same shape. axis : int, optional The axis in the result array along which the input arrays are stacked. |
|---|---|
| Returns: | stacked : ndarray The stacked array has one more dimension than the input arrays. |
See also
Join a sequence of arrays along an existing axis.
Split array into a list of multiple sub-arrays of equal size.
Assemble arrays from blocks.
Examples
arrays = [np.random.randn(3, 4) for _ in range(10)] np.stack(arrays, axis=0).shape (10, 3, 4)
np.stack(arrays, axis=1).shape (3, 10, 4)
np.stack(arrays, axis=2).shape (3, 4, 10)
a = np.array([1, 2, 3]) b = np.array([2, 3, 4]) np.stack((a, b)) array([[1, 2, 3], [2, 3, 4]])
np.stack((a, b), axis=-1) array([[1, 2], [2, 3], [3, 4]])