I have the following Numpy array:

```
arr = np.array([0.3, 3.5, 12.0, 2.9, 11.0, 23.0])

```

I want to reorder the array so it starts at the 4th position, followed by the items after the start position in order, followed by the items before the start position. I.e.

```
[2.9, 11.0, 23.0, 0.3, 3.5, 12.0]

```

How can I do this without a for loop?