def test_bias_limits(self):
""" Test case to ensure that if bias is outside (0, 1), it will fail.
"""
self.assertRaises(ValueError,
lambda: randomization.efrons_biased_coin(100000, -1))
self.assertRaises(ValueError,
lambda: randomization.efrons_biased_coin(100000, 0))
self.assertRaises(ValueError,
lambda: randomization.efrons_biased_coin(100000, 1))
self.assertRaises(ValueError,
lambda: randomization.efrons_biased_coin(100000, 1.5))
def test_distribution(self):
""" Test Case to ensure the distribution of groups is close to uniform.
Note: This test MAY fail. It is entirely possible, with a probability
of :math:`2^{-n}` where :math:`n` is the number of subjects to randomize
"""
result = randomization.efrons_biased_coin(100000)
percent_group_1 = (float(sum([value == 1 for value in result])) /
float(len(result)))
self.assertTrue(percent_group_1 > 0.48)
self.assertTrue(percent_group_1 < 0.52)
# Test with bias set
result = randomization.efrons_biased_coin(100000, 0.8)
percent_group_1 = (float(sum([value == 1 for value in result])) /
float(len(result)))
self.assertTrue(percent_group_1 > 0.48)
self.assertTrue(percent_group_1 < 0.52)
def test_n_groups(self):
""" Test Case to ensure the correct number of groups are output"""
result = randomization.efrons_biased_coin(100)
self.assertEqual(len(set(result)), 2)
result = randomization.efrons_biased_coin(100, 0.8)
self.assertEqual(len(set(result)), 2)
def test_length(self):
""" Test Case to ensure the correct number of subjects are output"""
result = randomization.efrons_biased_coin(100)
self.assertEqual(len(result), 100)
result = randomization.efrons_biased_coin(100, 0.8)
self.assertEqual(len(result), 100)
