How to split a numpy array multiple times with multiple indices?

Question

I want to split at array multiple times at various indices.

Example:

y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

I want to split this array at indices 2, 4, 7 to generate the following result:

res = [[[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]]]

I tried using numpy.split but it seems to only be able to split once, not multiple times to generate the result matrix. Is there a way to do this using numpy's vectorized operations without using loops?

j1-lee · Accepted Answer · 2021-10-13 02:16:44Z

2

I don't think there is a vectorized operator. The result itself is not a typical matrix since it is not rectangular. Alternatively, you can simply use list comprehension.

y = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]

split_at = [2, 4, 7]
output = [[y[:x], y[x:]] for x in split_at]
print(output) # [[[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]]]

edited Oct 13, 2021 at 2:16

answered Oct 13, 2021 at 1:52

j1-lee

13.9k3 gold badges16 silver badges27 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

How to split a numpy array multiple times with multiple indices?

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related