def test_empty_array(self):
self.assertEquals(plus_minus([]), [0, 0, 0])
def test_unsorted_array(self):
self.assertEquals(plus_minus([-4, 3, -9, 0, 4, 1]),
[0.500000, 0.333333, 0.166667])
def test_none_value(self):
self.assertEquals(plus_minus(None), [0, 0, 0])
def test_asc_sorted_array(self):
self.assertEquals(plus_minus([-1, -1, 0, 1, 1]),
[0.400000, 0.400000, 0.200000])