Let's say I have a 2D array:
L = np.array([[1,2,3],
[4,5,6],
[7,8,9]])
I would like to make a 3D array from this, using a parameter N, such that (in this example, let's say N=4)
L2 = np.array([[[1,1,1,1],[2,2,2,2],[3,3,3,3]],
[[4,4,4,4],[5,5,5,5],[6,6,6,6]],
[[7,7,7,7],[8,8,8,8],[9,9,9,9]]])
Is there a nice way of doing this?
Cheers
CodePudding user response:
One option is to add another dimension, then repeat
along the new dimension.
N = 4
out = L[..., None].repeat(N, axis=-1)
Output:
array([[[1, 1, 1, 1],
[2, 2, 2, 2],
[3, 3, 3, 3]],
[[4, 4, 4, 4],
[5, 5, 5, 5],
[6, 6, 6, 6]],
[[7, 7, 7, 7],
[8, 8, 8, 8],
[9, 9, 9, 9]]])
CodePudding user response:
You can use a combination of swapaxes
and broadcast_to
:
N = 4
L2 = np.broadcast_to(L.swapaxes(0, 1), (N, *reversed(L.shape))).swapaxes(0, 2)
Output will be as desired.