numpy.atleast_3d — NumPy v2.2 Manual (original) (raw)

numpy.atleast_3d(*arys)[source]#

View inputs as arrays with at least three dimensions.

Parameters:

arys1, arys2, …array_like

One or more array-like sequences. Non-array inputs are converted to arrays. Arrays that already have three or more dimensions are preserved.

Returns:

res1, res2, …ndarray

An array, or tuple of arrays, each with a.ndim >= 3. Copies are avoided where possible, and views with three or more dimensions are returned. For example, a 1-D array of shape (N,) becomes a view of shape (1, N, 1), and a 2-D array of shape (M, N) becomes a view of shape (M, N, 1).

Examples

import numpy as np np.atleast_3d(3.0) array([[[3.]]])

x = np.arange(3.0) np.atleast_3d(x).shape (1, 3, 1)

x = np.arange(12.0).reshape(4,3) np.atleast_3d(x).shape (4, 3, 1) np.atleast_3d(x).base is x.base # x is a reshape, so not base itself True

for arr in np.atleast_3d([1, 2], [[1, 2]], [[[1, 2]]]): ... print(arr, arr.shape) ... [[[1] [2]]] (1, 2, 1) [[[1] [2]]] (1, 2, 1) [[[1 2]]] (1, 1, 2)