def _mpl(graph: PyGraph, self_loop: bool, **kwargs):
"""
Auxiliary function for drawing the lattice using matplotlib.
Args:
graph : graph to be drawn.
self_loop : Draw self-loops, which are edges connecting a node to itself.
**kwargs : Kwargs for drawing the lattice.
Raises:
MissingOptionalLibraryError: Requires matplotlib.
"""
# pylint: disable=unused-import
from matplotlib import pyplot as plt
if not self_loop:
self_loops = [(i, i) for i in range(graph.num_nodes())
if graph.has_edge(i, i)]
graph.remove_edges_from(self_loops)
mpl_draw(
graph=graph,
**kwargs,
)
plt.draw()
def _mpl(graph: PyGraph, self_loop: bool, **kwargs):
"""
Auxiliary function for drawing the lattice using matplotlib.
Args:
graph : graph to be drawn.
self_loop : Draw self-loops, which are edges connecting a node to itself.
**kwargs : Kwargs for drawing the lattice.
Raises:
MissingOptionalLibraryError: Requires matplotlib.
"""
if not HAS_MATPLOTLIB:
raise MissingOptionalLibraryError(
libname="Matplotlib", name="_mpl", pip_install="pip install matplotlib"
)
from matplotlib import pyplot as plt
if not self_loop:
self_loops = [(i, i) for i in range(graph.num_nodes()) if graph.has_edge(i, i)]
graph.remove_edges_from(self_loops)
mpl_draw(
graph=graph,
**kwargs,
)
plt.draw()
def run(self, dag):
"""run the layout method"""
qubits = dag.qubits
qubit_indices = {qubit: index for index, qubit in enumerate(qubits)}
interactions = []
for node in dag.op_nodes(include_directives=False):
len_args = len(node.qargs)
if len_args == 2:
interactions.append((qubit_indices[node.qargs[0]],
qubit_indices[node.qargs[1]]))
if len_args >= 3:
raise TranspilerError(
"VF2Layout only can handle 2-qubit gates or less. Node "
f"{node.name} ({node}) is {len_args}-qubit")
if self.strict_direction:
cm_graph = self.coupling_map.graph
im_graph = PyDiGraph(multigraph=False)
else:
cm_graph = self.coupling_map.graph.to_undirected()
im_graph = PyGraph(multigraph=False)
cm_nodes = list(cm_graph.node_indexes())
if self.seed != -1:
random.Random(self.seed).shuffle(cm_nodes)
shuffled_cm_graph = type(cm_graph)()
shuffled_cm_graph.add_nodes_from(cm_nodes)
new_edges = [(cm_nodes[edge[0]], cm_nodes[edge[1]])
for edge in cm_graph.edge_list()]
shuffled_cm_graph.add_edges_from_no_data(new_edges)
cm_nodes = [
k for k, v in sorted(enumerate(cm_nodes),
key=lambda item: item[1])
]
cm_graph = shuffled_cm_graph
im_graph.add_nodes_from(range(len(qubits)))
im_graph.add_edges_from_no_data(interactions)
mappings = vf2_mapping(cm_graph,
im_graph,
subgraph=True,
id_order=False,
induced=False)
try:
mapping = next(mappings)
stop_reason = "solution found"
layout = Layout({
qubits[im_i]: cm_nodes[cm_i]
for cm_i, im_i in mapping.items()
})
self.property_set["layout"] = layout
for reg in dag.qregs.values():
self.property_set["layout"].add_register(reg)
except StopIteration:
stop_reason = "nonexistent solution"
self.property_set["VF2Layout_stop_reason"] = stop_reason
def __init__(self, graph: PyGraph) -> None:
"""
Args:
graph: Input graph for Lattice. `graph.multigraph` must be False.
Raises:
ValueError: If `graph.multigraph` is True for a given graph, it is invalid.
"""
if graph.multigraph:
raise ValueError(
f"Invalid `graph.multigraph` {graph.multigraph} is given. "
"`graph.multigraph` must be `False`."
)
if graph.edges() == [None] * graph.num_edges():
weighted_edges = [edge + (1.0,) for edge in graph.edge_list()]
for start, end, weight in weighted_edges:
graph.update_edge(start, end, weight)
self._graph = graph
self.pos: Optional[dict] = None
def test_from_nodes_and_edges(self):
"""Test from_nodes_edges."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(6))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(0, 2, -1.0),
(2, 3, 2.0),
(4, 2, -1.0),
(4, 4, 3.0),
(2, 5, -1.0),
]
graph.add_edges_from(weighted_edge_list)
lattice = Lattice(graph)
target_num_nodes = 6
target_weighted_edge_list = [
(2, 5, -1.0),
(4, 4, 3),
(4, 2, -1.0),
(2, 3, 2.0),
(0, 2, -1.0),
(0, 1, 1.0 + 1.0j),
]
target_lattice = Lattice.from_nodes_and_edges(
target_num_nodes, target_weighted_edge_list)
self.assertTrue(
is_isomorphic(lattice.graph,
target_lattice.graph,
edge_matcher=lambda x, y: x == y))
def test_from_parameters(self):
"""Test from_parameters."""
coupling_matrix = np.array([[1.0, 1.0 + 1.0j, 2.0 - 2.0j],
[1.0 - 1.0j, 0.0, 0.0],
[2.0 + 2.0j, 0.0, 1.0]])
ism = cast(IsingModel, IsingModel.from_parameters(coupling_matrix))
with self.subTest("Check the graph."):
target_graph = PyGraph(multigraph=False)
target_graph.add_nodes_from(range(3))
target_weight = [(0, 0, 1.0), (0, 1, 1.0 + 1.0j),
(0, 2, 2.0 - 2.0j), (2, 2, 1.0)]
target_graph.add_edges_from(target_weight)
self.assertTrue(
is_isomorphic(ism.lattice.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the coupling matrix."):
assert_array_equal(ism.coupling_matrix(), coupling_matrix)
with self.subTest("Check the second q op representation."):
coupling = [
("Z_0 Z_1", 1.0 + 1.0j),
("Z_0 Z_2", 2.0 - 2.0j),
("X_0", 1.0),
("X_2", 1.0),
]
ham = coupling
self.assertSetEqual(set(ham), set(ism.second_q_ops().to_list()))
def test_nonnumeric_weight_raises(self):
"""Test the initialization with a graph with non-numeric edge weights raises."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(3))
graph.add_edges_from([(0, 1, 1), (1, 2, "banana")])
with self.assertRaises(ValueError):
_ = Lattice(graph)
def test_init(self):
"""Test init."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(3))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(0, 2, -1.0),
(1, 1, 2.0),
]
graph.add_edges_from(weighted_edge_list)
lattice = Lattice(graph)
fhm = FermiHubbardModel(lattice, onsite_interaction=10.0)
with self.subTest("Check the graph."):
self.assertTrue(
is_isomorphic(fhm.lattice.graph,
lattice.graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the hopping matrix"):
hopping_matrix = fhm.hopping_matrix()
target_matrix = np.array([[0.0, 1.0 + 1.0j, -1.0],
[1.0 - 1.0j, 2.0, 0.0], [-1.0, 0.0,
0.0]])
assert_array_equal(hopping_matrix, target_matrix)
with self.subTest("Check the second q op representation."):
hopping = [
("+_0 -_2", 1.0 + 1.0j),
("-_0 +_2", -(1.0 - 1.0j)),
("+_0 -_4", -1.0),
("-_0 +_4", 1.0),
("+_1 -_3", 1.0 + 1.0j),
("-_1 +_3", -(1.0 - 1.0j)),
("+_1 -_5", -1.0),
("-_1 +_5", 1.0),
("+_2 -_2", 2.0),
("+_3 -_3", 2.0),
]
interaction = [
("+_0 -_0 +_1 -_1", 10.0),
("+_2 -_2 +_3 -_3", 10.0),
("+_4 -_4 +_5 -_5", 10.0),
]
ham = hopping + interaction
self.assertSetEqual(
set(ham),
set(fhm.second_q_ops(display_format="sparse").to_list()))
def test_from_parameters(self):
"""Test from_parameters."""
hopping_matrix = np.array([[1.0, 1.0 + 1.0j, 2.0 + 2.0j],
[1.0 - 1.0j, 0.0, 0.0],
[2.0 - 2.0j, 0.0, 1.0]])
onsite_interaction = 10.0
fhm = FermiHubbardModel.from_parameters(hopping_matrix,
onsite_interaction)
with self.subTest("Check the graph."):
target_graph = PyGraph(multigraph=False)
target_graph.add_nodes_from(range(3))
target_weight = [(0, 0, 1.0), (0, 1, 1.0 + 1.0j),
(0, 2, 2.0 + 2.0j), (2, 2, 1.0)]
target_graph.add_edges_from(target_weight)
self.assertTrue(
is_isomorphic(fhm.lattice.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the hopping matrix."):
assert_array_equal(fhm.hopping_matrix(), hopping_matrix)
with self.subTest("Check the second q op representation."):
hopping = [
("+_0 -_2", 1.0 + 1.0j),
("-_0 +_2", -(1.0 - 1.0j)),
("+_0 -_4", 2.0 + 2.0j),
("-_0 +_4", -(2.0 - 2.0j)),
("+_1 -_3", 1.0 + 1.0j),
("-_1 +_3", -(1.0 - 1.0j)),
("+_1 -_5", 2.0 + 2.0j),
("-_1 +_5", -(2.0 - 2.0j)),
("+_0 -_0", 1.0),
("+_1 -_1", 1.0),
("+_4 -_4", 1.0),
("+_5 -_5", 1.0),
]
interaction = [
("+_0 -_0 +_1 -_1", onsite_interaction),
("+_2 -_2 +_3 -_3", onsite_interaction),
("+_4 -_4 +_5 -_5", onsite_interaction),
]
ham = hopping + interaction
self.assertSetEqual(
set(ham),
set(fhm.second_q_ops(display_format="sparse").to_list()))
def build_interaction_graph(dag, strict_direction=True):
"""Build an interaction graph from a dag."""
if strict_direction:
im_graph = PyDiGraph(multigraph=False)
else:
im_graph = PyGraph(multigraph=False)
im_graph_node_map = {}
reverse_im_graph_node_map = {}
for node in dag.op_nodes(include_directives=False):
len_args = len(node.qargs)
if len_args == 1:
if node.qargs[0] not in im_graph_node_map:
weight = defaultdict(int)
weight[node.name] += 1
im_graph_node_map[node.qargs[0]] = im_graph.add_node(weight)
reverse_im_graph_node_map[im_graph_node_map[
node.qargs[0]]] = node.qargs[0]
else:
im_graph[im_graph_node_map[node.qargs[0]]][node.op.name] += 1
if len_args == 2:
if node.qargs[0] not in im_graph_node_map:
im_graph_node_map[node.qargs[0]] = im_graph.add_node(
defaultdict(int))
reverse_im_graph_node_map[im_graph_node_map[
node.qargs[0]]] = node.qargs[0]
if node.qargs[1] not in im_graph_node_map:
im_graph_node_map[node.qargs[1]] = im_graph.add_node(
defaultdict(int))
reverse_im_graph_node_map[im_graph_node_map[
node.qargs[1]]] = node.qargs[1]
edge = (im_graph_node_map[node.qargs[0]],
im_graph_node_map[node.qargs[1]])
if im_graph.has_edge(*edge):
im_graph.get_edge_data(*edge)[node.name] += 1
else:
weight = defaultdict(int)
weight[node.name] += 1
im_graph.add_edge(*edge, weight)
if len_args > 2:
return None
return im_graph, im_graph_node_map, reverse_im_graph_node_map
def test_to_adjacency_matrix(self):
"""Test to_adjacency_matrix."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(3))
weighted_edge_list = [(0, 1, 1.0 + 1.0j), (0, 2, -1.0), (2, 2, 3)]
graph.add_edges_from(weighted_edge_list)
lattice = Lattice(graph)
target_matrix = np.array([[0, 1 + 1j, -1.0], [1 - 1j, 0, 0],
[-1.0, 0, 3.0]])
assert_array_equal(lattice.to_adjacency_matrix(weighted=True),
target_matrix)
target_matrix = np.array([[0, 1, 1], [1, 0, 0], [1, 0, 1]])
assert_array_equal(lattice.to_adjacency_matrix(), target_matrix)
def from_nodes_and_edges(
cls, num_nodes: int, weighted_edges: List[Tuple[int, int, complex]]
) -> "Lattice":
"""Return an instance of Lattice from the number of nodes and the list of edges.
Args:
num_nodes: The number of nodes.
weighted_edges: A list of tuples consisting of two nodes and the weight between them.
Returns:
Lattice generated from lists of nodes and edges.
"""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(num_nodes))
graph.add_edges_from(weighted_edges)
return cls(graph)
def test_from_networkx(self):
"""Test initialization from a networkx graph."""
graph = nx.Graph()
graph.add_nodes_from(range(5))
graph.add_edges_from([(i, i + 1) for i in range(4)])
lattice = Lattice(graph)
target_graph = PyGraph()
target_graph.add_nodes_from(range(5))
target_graph.add_edges_from([(i, i + 1, 1) for i in range(4)])
self.assertTrue(
is_isomorphic(lattice.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
def _generate_lattice_from_parameters(interaction_matrix: np.ndarray):
# make a graph from the interaction matrix.
# This should be replaced by from_adjacency_matrix of retworkx.
shape = interaction_matrix.shape
if len(shape) != 2 or shape[0] != shape[1]:
raise ValueError(
f"Invalid shape of `interaction_matrix`, {shape}, is given."
"It must be a square matrix.")
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(shape[0]))
for source_index in range(shape[0]):
for target_index in range(source_index, shape[0]):
weight = interaction_matrix[source_index, target_index]
if not weight == 0.0:
graph.add_edge(source_index, target_index, weight)
return Lattice(graph)
def test_copy(self):
"""Test test_copy."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(6))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(0, 2, -1.0),
(2, 3, 2.0),
(2, 4, -1.0),
(4, 4, 3.0),
(2, 5, -1.0),
]
graph.add_edges_from(weighted_edge_list)
lattice = Lattice(graph)
lattice_copy = lattice.copy()
self.assertTrue(
is_isomorphic(lattice_copy.graph,
graph,
edge_matcher=lambda x, y: x == y))
def test_init(self):
"""Test init."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(3))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(0, 2, -1.0),
(1, 1, 2.0),
]
graph.add_edges_from(weighted_edge_list)
lattice = Lattice(graph)
ism = IsingModel(lattice)
with self.subTest("Check the graph."):
self.assertTrue(
is_isomorphic(ism.lattice.graph,
lattice.graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the coupling matrix"):
coupling_matrix = ism.coupling_matrix()
target_matrix = np.array([[0.0, 1.0 + 1.0j, -1.0],
[1.0 - 1.0j, 2.0, 0.0], [-1.0, 0.0,
0.0]])
assert_array_equal(coupling_matrix, target_matrix)
with self.subTest("Check the second q op representation."):
coupling = [
("Z_0 Z_1", 1.0 + 1.0j),
("Z_0 Z_2", -1.0),
("X_1", 2.0),
]
ham = coupling
self.assertSetEqual(set(ham), set(ism.second_q_ops().to_list()))
def from_json(cls, s: str) -> 'Topology':
"""Initializes from a JSON string."""
# load dict from JSON string
data = orjson.loads(s)
# validate type
_type = data.pop("type")
if _type != cls.__name__:
raise TypeError(f"cannot deserialize from type `{_type}`")
# initialize an empty graph
graph = PyGraph()
# process atoms
for atom in data["atoms"]:
graph.add_node(Atom.from_json(orjson.dumps(atom)))
# process bonds
for bond in data["bonds"]:
bond = Bond.from_json(orjson.dumps(bond))
graph.add_edge(bond.indices[0], bond.indices[1], edge=bond)
# return instance
return cls(graph)
def test_init(self):
"""Test init."""
rows = 3
cols = 2
edge_parameter = (1.0 + 1.0j, 2.0 + 2.0j)
onsite_parameter = 1.0
boundary_condition = (BoundaryCondition.PERIODIC,
BoundaryCondition.OPEN)
square = SquareLattice(rows, cols, edge_parameter, onsite_parameter,
boundary_condition)
with self.subTest("Check the graph."):
target_graph = PyGraph(multigraph=False)
target_graph.add_nodes_from(range(6))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(1, 2, 1.0 + 1.0j),
(0, 2, 1.0 - 1.0j),
(3, 4, 1.0 + 1.0j),
(4, 5, 1.0 + 1.0j),
(3, 5, 1.0 - 1.0j),
(0, 3, 2.0 + 2.0j),
(1, 4, 2.0 + 2.0j),
(2, 5, 2.0 + 2.0j),
(0, 0, 1.0),
(1, 1, 1.0),
(2, 2, 1.0),
(3, 3, 1.0),
(4, 4, 1.0),
(5, 5, 1.0),
]
target_graph.add_edges_from(weighted_edge_list)
self.assertTrue(
is_isomorphic(square.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the number of nodes."):
self.assertEqual(square.num_nodes, 6)
with self.subTest("Check the set of nodes."):
self.assertSetEqual(set(square.node_indexes), set(range(6)))
with self.subTest("Check the set of weights."):
target_set = {
(0, 1, 1.0 + 1.0j),
(1, 2, 1.0 + 1.0j),
(0, 2, 1.0 - 1.0j),
(3, 4, 1.0 + 1.0j),
(4, 5, 1.0 + 1.0j),
(3, 5, 1.0 - 1.0j),
(0, 3, 2.0 + 2.0j),
(1, 4, 2.0 + 2.0j),
(2, 5, 2.0 + 2.0j),
(0, 0, 1.0),
(1, 1, 1.0),
(2, 2, 1.0),
(3, 3, 1.0),
(4, 4, 1.0),
(5, 5, 1.0),
}
self.assertSetEqual(set(square.weighted_edge_list), target_set)
with self.subTest("Check the adjacency matrix."):
target_matrix = np.array([
[1.0, 1.0 + 1.0j, 1.0 - 1.0j, 2.0 + 2.0j, 0.0, 0.0],
[1.0 - 1.0j, 1.0, 1.0 + 1.0j, 0.0, 2.0 + 2.0j, 0.0],
[1.0 + 1.0j, 1.0 - 1.0j, 1.0, 0.0, 0.0, 2.0 + 2.0j],
[2.0 - 2.0j, 0.0, 0.0, 1.0, 1.0 + 1.0j, 1.0 - 1.0j],
[0.0, 2.0 - 2.0j, 0.0, 1.0 - 1.0j, 1.0, 1.0 + 1.0j],
[0.0, 0.0, 2.0 - 2.0j, 1.0 + 1.0j, 1.0 - 1.0j, 1.0],
])
assert_array_equal(square.to_adjacency_matrix(weighted=True),
target_matrix)
def test_uniform_parameters(self):
"""Test uniform_parameters."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(3))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(0, 2, -1.0),
(1, 1, 2.0),
]
graph.add_edges_from(weighted_edge_list)
lattice = Lattice(graph)
uniform_ism = cast(
IsingModel,
IsingModel.uniform_parameters(
lattice,
uniform_interaction=1.0 + 1.0j,
uniform_onsite_potential=0.0,
),
)
with self.subTest("Check the graph."):
target_graph = PyGraph(multigraph=False)
target_graph.add_nodes_from(range(3))
target_weight = [
(0, 1, 1.0 + 1.0j),
(0, 2, 1.0 + 1.0j),
(0, 0, 0.0),
(1, 1, 0.0),
(2, 2, 0.0),
]
target_graph.add_edges_from(target_weight)
self.assertTrue(
is_isomorphic(uniform_ism.lattice.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the coupling matrix."):
coupling_matrix = uniform_ism.coupling_matrix()
target_matrix = np.array([[0.0, 1.0 + 1.0j, 1.0 + 1.0j],
[1.0 - 1.0j, 0.0, 0.0],
[1.0 - 1.0j, 0.0, 0.0]])
assert_array_equal(coupling_matrix, target_matrix)
with self.subTest("Check the second q op representation."):
coupling = [
("Z_0 Z_1", 1.0 + 1.0j),
("Z_0 Z_2", 1.0 + 1.0j),
("X_0", 0.0),
("X_1", 0.0),
("X_2", 0.0),
]
ham = coupling
self.assertSetEqual(set(ham),
set(uniform_ism.second_q_ops().to_list()))
def __init__(
self,
size: Tuple[int, ...],
edge_parameter: Union[complex, Tuple[complex, ...]] = 1.0,
onsite_parameter: complex = 0.0,
boundary_condition: Union[
BoundaryCondition, Tuple[BoundaryCondition, ...]
] = BoundaryCondition.OPEN,
) -> None:
"""
Args:
size: Lengths of each dimension.
edge_parameter: Weights on the edges in each direction.
When it is a single value, it is interpreted as a tuple of the same length as `size`
consisting of the same values.
Defaults to 1.0.
onsite_parameter: Weight on the self-loops, which are edges connecting a node to itself.
This is uniform over the lattice points.
Defaults to 0.0.
boundary_condition: Boundary condition for each dimension.
The available boundary conditions are:
BoundaryCondition.OPEN, BoundaryCondition.PERIODIC.
When it is a single value, it is interpreted as a tuple of the same length as `size`
consisting of the same values.
Defaults to BoundaryCondition.OPEN.
Raises:
ValueError: When edge parameter or boundary condition is a tuple,
the length of that is not the same as that of size.
"""
self._dim = len(size)
self._size = size
# edge parameter
if isinstance(edge_parameter, (int, float, complex)):
edge_parameter = (edge_parameter,) * self._dim
elif isinstance(edge_parameter, tuple):
if len(edge_parameter) != self._dim:
raise ValueError(
"size mismatch, "
f"`edge_parameter`: {len(edge_parameter)}, `size`: {self._dim}."
"The length of `edge_parameter` must be the same as that of size."
)
self._edge_parameter = edge_parameter
self._onsite_parameter = onsite_parameter
# boundary condition
if isinstance(boundary_condition, BoundaryCondition):
boundary_condition = (boundary_condition,) * self._dim
elif isinstance(boundary_condition, tuple):
if len(boundary_condition) != self._dim:
raise ValueError(
"size mismatch, "
f"`boundary_condition`: {len(boundary_condition)}, `size`: {self._dim}."
"The length of `boundary_condition` must be the same as that of size."
)
self._boundary_condition = boundary_condition
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(np.prod(size)))
# add edges excluding the boundary edges
bulk_edge_list = self._bulk_edges()
graph.add_edges_from(bulk_edge_list)
# add self-loops.
self_loop_list = self._self_loops()
graph.add_edges_from(self_loop_list)
# add edges that cross the boundaries
boundary_edge_list = self._create_boundary_edges()
graph.add_edges_from(boundary_edge_list)
# a list of edges that depend on the boundary condition
self._boundary_edges = [(edge[0], edge[1]) for edge in boundary_edge_list]
super().__init__(graph)
# default position for one and two-dimensional cases.
self.pos = self._default_position()
def __init__(
self,
rows: int,
cols: int,
edge_parameter: Union[complex, Tuple[complex, complex, complex]] = 1.0,
onsite_parameter: complex = 0.0,
boundary_condition: BoundaryCondition = BoundaryCondition.OPEN,
) -> None:
"""
Args:
rows: Length of the x direction.
cols: Length of the y direction.
edge_parameter: Weights on the edges in x, y and diagonal directions.
This is specified as a tuple of length 3 or a single value.
When it is a single value, it is interpreted as a tuple of length 3
consisting of the same values.
Defaults to 1.0,
onsite_parameter: Weight on the self-loops, which are edges connecting a node to itself.
Defaults to 0.0.
boundary_condition: Boundary condition for the lattice.
The available boundary conditions are:
BoundaryCondition.OPEN, BoundaryCondition.PERIODIC.
Defaults to BoundaryCondition.OPEN.
Raises:
ValueError: Given size, edge parameter or boundary condition are invalid values.
"""
self.rows = rows
self.cols = cols
self.size = (rows, cols)
self.dim = 2
self.boundary_condition = boundary_condition
if rows < 2 or cols < 2 or (rows, cols) == (2, 2):
# If it's True, triangular lattice can't be well defined.
raise ValueError("Both of `rows` and `cols` must not be (2, 2)"
"and must be greater than or equal to 2.")
if isinstance(edge_parameter, (int, float, complex)):
edge_parameter = (edge_parameter, edge_parameter, edge_parameter)
elif isinstance(edge_parameter, tuple):
if len(edge_parameter) != 3:
raise ValueError(
f"The length of `edge_parameter` must be 3, not {len(edge_parameter)}."
)
self.edge_parameter = edge_parameter
self.onsite_parameter = onsite_parameter
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(np.prod(self.size)))
# add edges excluding the boundary edges
bulk_edges = self._bulk_edges()
graph.add_edges_from(bulk_edges)
# add self-loops
self_loop_list = self._self_loops()
graph.add_edges_from(self_loop_list)
# add edges that cross the boundaries
boundary_edge_list = self._boundary_edges()
graph.add_edges_from(boundary_edge_list)
# a list of edges that depend on the boundary condition
self.boundary_edges = [(edge[0], edge[1])
for edge in boundary_edge_list]
super().__init__(graph)
# default position
self.pos = self._default_position()
def test_init(self):
"""Test init."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(6))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(0, 2, -1.0),
(2, 3, 2.0),
(2, 4, -1.0),
(4, 4, 3.0),
(2, 5, -1.0),
]
graph.add_edges_from(weighted_edge_list)
lattice = Lattice(graph)
with self.subTest("Check the type of lattice."):
self.assertIsInstance(lattice, Lattice)
with self.subTest("Check graph."):
target_graph = PyGraph(multigraph=False)
target_graph.add_nodes_from(range(6))
target_weighted_edge_list = [
(4, 4, 3.0),
(0, 1, 1 + 1j),
(2, 3, 2.0),
(2, 4, -1.0),
(2, 5, -1.0),
(0, 2, -1),
]
target_graph.add_edges_from(target_weighted_edge_list)
self.assertTrue(
is_isomorphic(lattice.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the number of nodes."):
self.assertEqual(lattice.num_nodes, 6)
with self.subTest("Check the set of nodes."):
self.assertSetEqual(set(lattice.node_indexes), set(range(6)))
with self.subTest("Check the set of weights."):
target_set = {
(0, 1, 1 + 1j),
(4, 4, 3),
(2, 5, -1.0),
(0, 2, -1.0),
(2, 3, 2.0),
(2, 4, -1.0),
}
self.assertEqual(set(lattice.weighted_edge_list), target_set)
def test_edges_removed(self):
"""Test the initialization with a graph where edges have been removed."""
graph = PyGraph(multigraph=False)
graph.add_nodes_from(range(3))
graph.add_edges_from([(0, 1, 1), (1, 2, 1)])
graph.remove_edge_from_index(0)
lattice = Lattice(graph)
target_graph = PyGraph(multigraph=False)
target_graph.add_nodes_from(range(3))
target_graph.add_edges_from([(1, 2, 1)])
self.assertTrue(
is_isomorphic(lattice.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
def run(self, dag):
"""run the layout method"""
if self.coupling_map is None:
raise TranspilerError("coupling_map or target must be specified.")
qubits = dag.qubits
qubit_indices = {qubit: index for index, qubit in enumerate(qubits)}
interactions = []
for node in dag.op_nodes(include_directives=False):
len_args = len(node.qargs)
if len_args == 2:
interactions.append((qubit_indices[node.qargs[0]],
qubit_indices[node.qargs[1]]))
if len_args >= 3:
self.property_set[
"VF2Layout_stop_reason"] = VF2LayoutStopReason.MORE_THAN_2Q
return
if self.strict_direction:
cm_graph = self.coupling_map.graph
im_graph = PyDiGraph(multigraph=False)
else:
cm_graph = self.coupling_map.graph.to_undirected()
im_graph = PyGraph(multigraph=False)
cm_nodes = list(cm_graph.node_indexes())
if self.seed != -1:
random.Random(self.seed).shuffle(cm_nodes)
shuffled_cm_graph = type(cm_graph)()
shuffled_cm_graph.add_nodes_from(cm_nodes)
new_edges = [(cm_nodes[edge[0]], cm_nodes[edge[1]])
for edge in cm_graph.edge_list()]
shuffled_cm_graph.add_edges_from_no_data(new_edges)
cm_nodes = [
k for k, v in sorted(enumerate(cm_nodes),
key=lambda item: item[1])
]
cm_graph = shuffled_cm_graph
im_graph.add_nodes_from(range(len(qubits)))
im_graph.add_edges_from_no_data(interactions)
# To avoid trying to over optimize the result by default limit the number
# of trials based on the size of the graphs. For circuits with simple layouts
# like an all 1q circuit we don't want to sit forever trying every possible
# mapping in the search space
if self.max_trials is None:
im_graph_edge_count = len(im_graph.edge_list())
cm_graph_edge_count = len(cm_graph.edge_list())
self.max_trials = max(im_graph_edge_count,
cm_graph_edge_count) + 15
logger.debug("Running VF2 to find mappings")
mappings = vf2_mapping(
cm_graph,
im_graph,
subgraph=True,
id_order=False,
induced=False,
call_limit=self.call_limit,
)
chosen_layout = None
chosen_layout_score = None
start_time = time.time()
trials = 0
for mapping in mappings:
trials += 1
logger.debug("Running trial: %s", trials)
stop_reason = VF2LayoutStopReason.SOLUTION_FOUND
layout = Layout({
qubits[im_i]: cm_nodes[cm_i]
for cm_i, im_i in mapping.items()
})
# If the graphs have the same number of nodes we don't need to score or do multiple
# trials as the score heuristic currently doesn't weigh nodes based on gates on a
# qubit so the scores will always all be the same
if len(cm_graph) == len(im_graph):
chosen_layout = layout
break
layout_score = self._score_layout(layout)
logger.debug("Trial %s has score %s", trials, layout_score)
if chosen_layout is None:
chosen_layout = layout
chosen_layout_score = layout_score
elif layout_score < chosen_layout_score:
logger.debug(
"Found layout %s has a lower score (%s) than previous best %s (%s)",
layout,
layout_score,
chosen_layout,
chosen_layout_score,
)
chosen_layout = layout
chosen_layout_score = layout_score
if self.max_trials > 0 and trials >= self.max_trials:
logger.debug("Trial %s is >= configured max trials %s", trials,
self.max_trials)
break
elapsed_time = time.time() - start_time
if self.time_limit is not None and elapsed_time >= self.time_limit:
logger.debug(
"VF2Layout has taken %s which exceeds configured max time: %s",
elapsed_time,
self.time_limit,
)
break
if chosen_layout is None:
stop_reason = VF2LayoutStopReason.NO_SOLUTION_FOUND
else:
self.property_set["layout"] = chosen_layout
for reg in dag.qregs.values():
self.property_set["layout"].add_register(reg)
self.property_set["VF2Layout_stop_reason"] = stop_reason
def __init__(self, graph: Optional[PyGraph] = None) -> None:
if graph is None:
graph = PyGraph()
self._graph = graph
def test_init(self):
"""Test init."""
size = (2, 2, 2)
edge_parameter = (1.0 + 1.0j, 0.0, -2.0 - 2.0j)
onsite_parameter = 5.0
boundary_condition = (
BoundaryCondition.OPEN,
BoundaryCondition.PERIODIC,
BoundaryCondition.OPEN,
)
hyper_cubic = HyperCubicLattice(size, edge_parameter, onsite_parameter,
boundary_condition)
with self.subTest("Check the graph."):
target_graph = PyGraph(multigraph=False)
target_graph.add_nodes_from(range(8))
weighted_edge_list = [
(0, 1, 1.0 + 1.0j),
(2, 3, 1.0 + 1.0j),
(4, 5, 1.0 + 1.0j),
(6, 7, 1.0 + 1.0j),
(0, 2, 0.0),
(1, 3, 0.0),
(4, 6, 0.0),
(5, 7, 0.0),
(0, 4, -2.0 - 2.0j),
(1, 5, -2.0 - 2.0j),
(2, 6, -2.0 - 2.0j),
(3, 7, -2.0 - 2.0j),
(0, 0, 5.0),
(1, 1, 5.0),
(2, 2, 5.0),
(3, 3, 5.0),
(4, 4, 5.0),
(5, 5, 5.0),
(6, 6, 5.0),
(7, 7, 5.0),
]
target_graph.add_edges_from(weighted_edge_list)
self.assertTrue(
is_isomorphic(hyper_cubic.graph,
target_graph,
edge_matcher=lambda x, y: x == y))
with self.subTest("Check the number of nodes."):
self.assertEqual(hyper_cubic.num_nodes, 8)
with self.subTest("Check the set of nodes."):
self.assertSetEqual(set(hyper_cubic.node_indexes), set(range(8)))
with self.subTest("Check the set of weights."):
target_set = {
(0, 1, 1.0 + 1.0j),
(2, 3, 1.0 + 1.0j),
(4, 5, 1.0 + 1.0j),
(6, 7, 1.0 + 1.0j),
(0, 2, 0.0),
(1, 3, 0.0),
(4, 6, 0.0),
(5, 7, 0.0),
(0, 4, -2.0 - 2.0j),
(1, 5, -2.0 - 2.0j),
(2, 6, -2.0 - 2.0j),
(3, 7, -2.0 - 2.0j),
(0, 0, 5.0),
(1, 1, 5.0),
(2, 2, 5.0),
(3, 3, 5.0),
(4, 4, 5.0),
(5, 5, 5.0),
(6, 6, 5.0),
(7, 7, 5.0),
}
self.assertSetEqual(set(hyper_cubic.weighted_edge_list),
target_set)
with self.subTest("Check the adjacency matrix."):
target_matrix = np.array([
[5.0, 1.0 + 1.0j, 0.0, 0.0, -2.0 - 2.0j, 0.0, 0.0, 0.0],
[1.0 - 1.0j, 5.0, 0.0, 0.0, 0.0, -2.0 - 2.0j, 0.0, 0.0],
[0.0, 0.0, 5.0, 1.0 + 1.0j, 0.0, 0.0, -2.0 - 2.0j, 0.0],
[0.0, 0.0, 1.0 - 1.0j, 5.0, 0.0, 0.0, 0.0, -2.0 - 2.0j],
[-2.0 + 2.0j, 0.0, 0.0, 0.0, 5.0, 1.0 + 1.0j, 0.0, 0.0],
[0.0, -2.0 + 2.0j, 0.0, 0.0, 1.0 - 1.0j, 5.0, 0.0, 0.0],
[0.0, 0.0, -2.0 + 2.0j, 0.0, 0.0, 0.0, 5.0, 1.0 + 1.0j],
[0.0, 0.0, 0.0, -2.0 + 2.0j, 0.0, 0.0, 1.0 - 1.0j, 5.0],
])
assert_array_equal(hyper_cubic.to_adjacency_matrix(weighted=True),
target_matrix)
def run(self, dag):
"""run the layout method"""
if self.target is None and (self.coupling_map is None or self.properties is None):
raise TranspilerError(
"A target must be specified or a coupling map and properties must be provided"
)
if not self.strict_direction and self.avg_error_map is None:
self.avg_error_map = vf2_utils.build_average_error_map(
self.target, self.properties, self.coupling_map
)
result = vf2_utils.build_interaction_graph(dag, self.strict_direction)
if result is None:
self.property_set["VF2PostLayout_stop_reason"] = VF2PostLayoutStopReason.MORE_THAN_2Q
return
im_graph, im_graph_node_map, reverse_im_graph_node_map = result
if self.target is not None:
if self.strict_direction:
cm_graph = PyDiGraph(multigraph=False)
else:
cm_graph = PyGraph(multigraph=False)
cm_graph.add_nodes_from(
[self.target.operation_names_for_qargs((i,)) for i in range(self.target.num_qubits)]
)
for qargs in self.target.qargs:
len_args = len(qargs)
# If qargs == 1 we already populated it and if qargs > 2 there are no instructions
# using those in the circuit because we'd have already returned by this point
if len_args == 2:
cm_graph.add_edge(
qargs[0], qargs[1], self.target.operation_names_for_qargs(qargs)
)
cm_nodes = list(cm_graph.node_indexes())
else:
cm_graph, cm_nodes = vf2_utils.shuffle_coupling_graph(
self.coupling_map, self.seed, self.strict_direction
)
logger.debug("Running VF2 to find post transpile mappings")
if self.target and self.strict_direction:
mappings = vf2_mapping(
cm_graph,
im_graph,
node_matcher=_target_match,
edge_matcher=_target_match,
subgraph=True,
id_order=False,
induced=False,
call_limit=self.call_limit,
)
else:
mappings = vf2_mapping(
cm_graph,
im_graph,
subgraph=True,
id_order=False,
induced=False,
call_limit=self.call_limit,
)
chosen_layout = None
initial_layout = Layout(dict(enumerate(dag.qubits)))
try:
if self.strict_direction:
chosen_layout_score = self._score_layout(
initial_layout, im_graph_node_map, reverse_im_graph_node_map, im_graph
)
else:
chosen_layout_score = vf2_utils.score_layout(
self.avg_error_map,
initial_layout,
im_graph_node_map,
reverse_im_graph_node_map,
im_graph,
self.strict_direction,
)
# Circuit not in basis so we have nothing to compare against return here
except KeyError:
self.property_set[
"VF2PostLayout_stop_reason"
] = VF2PostLayoutStopReason.NO_SOLUTION_FOUND
return
logger.debug("Initial layout has score %s", chosen_layout_score)
start_time = time.time()
trials = 0
for mapping in mappings:
trials += 1
logger.debug("Running trial: %s", trials)
stop_reason = VF2PostLayoutStopReason.SOLUTION_FOUND
layout = Layout(
{reverse_im_graph_node_map[im_i]: cm_nodes[cm_i] for cm_i, im_i in mapping.items()}
)
if self.strict_direction:
layout_score = self._score_layout(
layout, im_graph_node_map, reverse_im_graph_node_map, im_graph
)
else:
layout_score = vf2_utils.score_layout(
self.avg_error_map,
layout,
im_graph_node_map,
reverse_im_graph_node_map,
im_graph,
self.strict_direction,
)
logger.debug("Trial %s has score %s", trials, layout_score)
if layout_score < chosen_layout_score:
logger.debug(
"Found layout %s has a lower score (%s) than previous best %s (%s)",
layout,
layout_score,
chosen_layout,
chosen_layout_score,
)
chosen_layout = layout
chosen_layout_score = layout_score
elapsed_time = time.time() - start_time
if self.time_limit is not None and elapsed_time >= self.time_limit:
logger.debug(
"VFPostLayout has taken %s which exceeds configured max time: %s",
elapsed_time,
self.time_limit,
)
break
if chosen_layout is None:
stop_reason = VF2PostLayoutStopReason.NO_SOLUTION_FOUND
else:
existing_layout = self.property_set["layout"]
# If any ancillas in initial layout map them back to the final layout output
if existing_layout is not None and len(existing_layout) > len(chosen_layout):
virtual_bits = chosen_layout.get_virtual_bits()
used_bits = set(virtual_bits.values())
num_qubits = len(cm_graph)
for bit in dag.qubits:
if len(chosen_layout) == len(existing_layout):
break
if bit not in virtual_bits:
for i in range(num_qubits):
if i not in used_bits:
used_bits.add(i)
chosen_layout.add(bit, i)
break
self.property_set["post_layout"] = chosen_layout
self.property_set["VF2PostLayout_stop_reason"] = stop_reason