def test_merge_empty():
qd1 = QuantileDigest(3, 5)
q1_counts = qd1.count()
assert q1_counts == 0, "Incorrect number of elements"
qd2 = QuantileDigest(3, 5)
q2_counts = qd2.count()
assert q2_counts == 0, "Incorrect number of elements"
qd1.merge(qd2)
assert len(qd1) == 0, "Invalid length"
assert qd1.count() == 0, "Incorrect number of elements"
def test_merge_unmergeable():
qd1 = QuantileDigest(3, 5)
qd2 = QuantileDigest(3, 2)
with pytest.raises(ValueError) as excinfo:
qd1.merge(qd2)
assert str(excinfo.value) == 'Compression factors have to be equal'
qd1 = QuantileDigest(3, 5)
qd2 = QuantileDigest(4, 5)
with pytest.raises(ValueError) as excinfo:
qd1.merge(qd2)
assert str(excinfo.value) == 'Ranges have to be equal'
def test_merge():
qd1 = QuantileDigest(3, 5)
for i in range(8):
qd1.add(0)
for i in range(8):
qd1.add(1)
for i in range(4):
qd1.add(2)
for i in range(1):
qd1.add(3)
for i in range(5):
qd1.add(4)
for i in range(3):
qd1.add(5)
for i in range(5):
qd1.add(6)
for i in range(2):
qd1.add(7)
q1_counts = qd1.count()
qd1.compress()
qd2 = QuantileDigest(3, 5)
for i in range(10):
qd2.add(0)
for i in range(12):
qd2.add(1)
for i in range(8):
qd2.add(2)
for i in range(20):
qd2.add(3)
q2_counts = qd2.count()
qd2.compress()
qd1.merge(qd2)
assert qd1.count() == q1_counts + q2_counts, "Incorrect counts"
assert len(qd1) == 6, "Incorrect length"