How does the builtin function argpartition works?

[vicky53]

Hi Frnds,

I'm new to numpy.. Can you please explain how the builtin function argpartition works?

>>> x = np.array([3, 4, 2, 1])
>>> x[np.argpartition(x, 3)]
array([2, 1, 3, 4])
>>> x[np.argpartition(x, (1, 3))]
array([1, 2, 3, 4])
>>>
>>> x = [3, 4, 2, 1]
>>> np.array(x)[np.argpartition(x, 3)]
array([2, 1, 3, 4])

I tried to understand the above example, but unfortunately I couldn't..:(