How do I slice 3D arrays in NumPy?

How do I slice 3D arrays in NumPy?

You can slice 3D arrays in NumPy using the syntax array[start:stop:step]. For example, arr[1:3, :, :] slices the array along the first dimension.

Can you give me an example with actual numbers?

Sure! If you have a 3D array like this:

import numpy as np
arr = np.array([[[1, 2], [3, 4]], [[5, 6], [7, 8]], [[9, 10], [11, 12]]])

You can slice it with arr[0:2, :, :] to get:

array([[[1, 2], [3, 4]],
       [[5, 6], [7, 8]]])

What if I want to slice only the second element of the last dimension?

You can do that by specifying the index for the last dimension. For example, arr[:, :, 1] will give you:

array([[ 2, 4],
       [ 6, 8],
       [10, 12]])

Thanks! Is there a way to reverse the order of elements in a specific dimension?

Yes! You can reverse the order of elements in a specific dimension by using slicing. For example, arr[::-1, :, :] will reverse the first dimension.