def test_root_mean_square(self):
        self.assertAlmostEqualOnAllArrayTypes(
            root_mean_square, [1, 1, 1, 2, 2], 1.4832396974191
        )
        self.assertAlmostEqualOnAllArrayTypes(root_mean_square, [0], 0)
        self.assertIsNanOnAllArrayTypes(root_mean_square, [])
        self.assertAlmostEqualOnAllArrayTypes(root_mean_square, [1], 1)
        self.assertAlmostEqualOnAllArrayTypes(root_mean_square, [-1], 1)