How to duplicate a NumPy array to form a new array with several rows of the original array?

Question

I want to create a NumPy array by duplicating another array by a few rows. I did it as shown below. Is there a NumPyier way of doing this?

>>> a = np.arange(0,10)
>>> a
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> b = tuple( a for _ in range(3) )
>>> b
(array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]), array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]), array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]))
>>> c = np.vstack( b )
>>> c
array([[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
       [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
       [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]])

`np.broadcast_to(a, (3, a.shape[0]))` – user3483203 Aug 16 '20 at 14:01 — user3483203, Aug 16 '20 at 14:01

score 1 · Answer 1 · answered Aug 16 '20 at 13:34

I found a way to do it. Sharing it here.

>>> a
array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
>>> a[None,:]
array([[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]])
>>> np.repeat( a[None,:], 3, axis=0 )
array([[0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
       [0, 1, 2, 3, 4, 5, 6, 7, 8, 9],
       [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]])

How to duplicate a NumPy array to form a new array with several rows of the original array?

1 Answers1