def test_ratio_beyond_r_sigma(self):

        x = [0, 1] * 10 + [10, 20, -30]  # std of x is 7.21, mean 3.04
        self.assertEqualOnAllArrayTypes(ratio_beyond_r_sigma, x, 3.0 / len(x), r=1)
        self.assertEqualOnAllArrayTypes(ratio_beyond_r_sigma, x, 2.0 / len(x), r=2)
        self.assertEqualOnAllArrayTypes(ratio_beyond_r_sigma, x, 1.0 / len(x), r=3)
        self.assertEqualOnAllArrayTypes(ratio_beyond_r_sigma, x, 0, r=20)