def test_qubit_id_accepted_using_add_edge():
m = Matching()
m.add_edge(0, 1, qubit_id=0)
m.add_edge(1, 2, qubit_id={1, 2})
es = list(m.edges())
expected_edges = [
(0, 1, {'fault_ids': {0}, 'weight': 1.0, 'error_probability': -1.0}),
(1, 2, {'fault_ids': {1, 2}, 'weight': 1.0, 'error_probability': -1.0})
]
assert es == expected_edges
def test_add_edge():
m = Matching()
m.add_edge(0, 1)
m.add_edge(1, 2)
assert m.num_nodes == 3
assert m.num_edges == 2
m = Matching()
m.add_edge(0, 1, weight=0.123, error_probability=0.6)
m.add_edge(1, 2, weight=0.6, error_probability=0.3, fault_ids=0)
m.add_edge(2, 3, weight=0.01, error_probability=0.5, fault_ids={1, 2})
expected = [(0, 1, {'fault_ids': set(), 'weight': 0.123, 'error_probability': 0.6}),
(1, 2, {'fault_ids': {0}, 'weight': 0.6, 'error_probability': 0.3}),
(2, 3, {'fault_ids': {1, 2}, 'weight': 0.01, 'error_probability': 0.5})]
assert m.edges() == expected
def test_isolated_negative_weight(nn):
m = Matching()
m.add_edge(0, 1, 0, 1)
m.add_edge(1, 2, 1, -10)
m.add_edge(2, 3, 2, 1)
m.add_edge(3, 0, 3, 1)
c, w = m.decode([0, 1, 1, 0], return_weight=True, num_neighbours=nn)
assert np.array_equal(c, np.array([0, 1, 0, 0]))
assert w == -10
def test_negative_weight_repetition_code(nn):
m = Matching()
m.add_edge(0, 1, 0, -1)
m.add_edge(1, 2, 1, -1)
m.add_edge(2, 3, 2, -1)
m.add_edge(3, 4, 3, -1)
m.add_edge(4, 5, 4, -1)
m.add_edge(5, 0, 5, -1)
c, w = m.decode([0, 1, 1, 0, 0, 0], return_weight=True, num_neighbours=nn)
assert np.array_equal(c, np.array([1, 0, 1, 1, 1, 1]))
assert w == -5
def test_negative_weight_edge_returned():
m = Matching()
m.add_edge(0, 1, weight=0.5, error_probability=0.3)
m.add_edge(1, 2, weight=0.5, error_probability=0.3, fault_ids=0)
m.add_edge(2, 3, weight=-0.5, error_probability=0.7, fault_ids={1, 2})
expected = [(0, 1, {
'fault_ids': set(),
'weight': 0.5,
'error_probability': 0.3
}), (1, 2, {
'fault_ids': {0},
'weight': 0.5,
'error_probability': 0.3
}), (2, 3, {
'fault_ids': {1, 2},
'weight': -0.5,
'error_probability': 0.7
})]
assert m.edges() == expected
def test_add_edge_raises_value_error_if_qubit_id_and_fault_ids_both_supplied():
with pytest.raises(ValueError):
m = Matching()
m.add_edge(0, 1, qubit_id=0, fault_ids=0)
m.add_edge(1, 2, qubit_id=1, fault_ids=1)