Time for action – splitting arrays

1. Horizontal splitting: The ensuing code splits an array along its horizontal axis into three pieces of the same size and shape:

   In: a
   Out:
   array([[0, 1, 2],
          [3, 4, 5],
          [6, 7, 8]])
   In: hsplit(a, 3)
   Out:
   [array([[0],
          [3],
          [6]]),
    array([[1],
          [4],
          [7]]),
    array([[2],
          [5],
          [8]])]

   Compare it with a call of the split function, with extra parameter axis=1:

   In: split(a, 3, axis=1)
   Out:
   [array([[0],
          [3],
          [6]]),
    array([[1],
          [4],
          [7]]),
    array([[2],
          [5],
          [8]])]

2. Vertical splitting: The vsplit function splits along the vertical axis:

   In: vsplit(a, 3)
   Out: [array([[0, 1, 2]]), array([[3, 4, 5]]), array([[6, 7,8]])]

   The split function, with axis=0, also splits along the vertical axis:

   In: split(a, 3, axis=0)
   Out: [array([[0, 1, 2]]), array([[3, 4, 5]]), array([[6, 7,8]])]

3. Depth-wise splitting: The dsplit function, unsurprisingly, splits depth-wise. We will need an array of rank...