Split array s.t sub-arrays sum to original
<p>I'm trying to figure out a clever way to randomly split a numpy integer array into two parts so that the two parts sum to the original array.</p>

<p><strong>Example:</strong></p>

<pre><code>a = np.array([0,1,2,3])
b, c = rand_split(a)
# Should give something like
# b = [0, 1, 1, 2], c = [0, 0, 1, 1]
</code></pre>

<p>EDIT: All entries should be non-negative.</p>