def test_ordering(self):
hash_a = HashFunction(1, 3)
hash_b = HashFunction(1, 5)
hash_c = HashFunction(1, 5)
hash_d = HashFunction(2, 5)
self.assertLess(hash_a, hash_b)
self.assertLess(hash_c, hash_d)
def __init__(self, num_buckets, random_seed):
"""Creates a vector of counts sketch.
Args:
num_buckets: the number of buckets of the VectorOfCounts.
random_seed: a random seed for the hash function.
"""
SketchBase.__init__(self)
self._num_buckets = num_buckets
self.stats = np.zeros(num_buckets)
self.hash_function = HashFunction(random_seed, num_buckets)
self._vectorized_hash_function = np.vectorize(self.hash_function)
self._ids_added = False
def test_modulus_too_big(self): self.assertRaises(ValueError, lambda: HashFunction(42, 2**65))
def test_hashing(self): hash_a = HashFunction(1, 3) hash_b = HashFunction(1, 3) x = 137 self.assertEqual(hash_a(x), hash_b(x))
def test_equality(self):
hash_a = HashFunction(1, 3)
hash_b = HashFunction(1, 3)
self.assertEqual(hash_a, hash_b)
def test_inequality_mod(self):
hash_a = HashFunction(1, 5)
hash_b = HashFunction(1, 3)
self.assertNotEqual(hash_a, hash_b)