def copy(nodes: Iterable[BaseNode],
conjugate: bool = False) -> Tuple[dict, dict]:
"""Copy the given nodes and their edges.
This will return a dictionary linking original nodes/edges
to their copies.
Args:
nodes: An `Iterable` (Usually a `List` or `Set`) of `Nodes`.
conjugate: Boolean. Whether to conjugate all of the nodes
(useful for calculating norms and reduced density
matrices).
Returns:
A tuple containing:
node_dict: A dictionary mapping the nodes to their copies.
edge_dict: A dictionary mapping the edges to their copies.
"""
#TODO: add support for copying CopyTensor
if conjugate:
node_dict = {
node: Node(node.backend.conj(node.tensor),
name=node.name,
axis_names=node.axis_names,
backend=node.backend.name)
for node in nodes
}
else:
node_dict = {
node: Node(node.tensor,
name=node.name,
axis_names=node.axis_names,
backend=node.backend.name)
for node in nodes
}
edge_dict = {}
for edge in get_all_edges(nodes):
node1 = edge.node1
axis1 = edge.node1.get_axis_number(edge.axis1)
if not edge.is_dangling():
node2 = edge.node2
axis2 = edge.node2.get_axis_number(edge.axis2)
new_edge = Edge(node_dict[node1], axis1, edge.name,
node_dict[node2], axis2)
new_edge.set_signature(edge.signature)
else:
new_edge = Edge(node_dict[node1], axis1, edge.name)
node_dict[node1].add_edge(new_edge, axis1)
if not edge.is_dangling():
node_dict[node2].add_edge(new_edge, axis2)
edge_dict[edge] = new_edge
return node_dict, edge_dict
def copy(nodes: Iterable[BaseNode],
conjugate: bool = False) -> Tuple[dict, dict]:
"""Copy the given nodes and their edges.
This will return a tuple linking original nodes/edges to their copies.
If nodes A and B are connected but only A is passed in to be
copied, the edge between them will become a dangling edge.
Args:
nodes: An Iterable (Usually a `list` or `set`) of `nodes`.
conjugate: Boolean. Whether to conjugate all of the nodes
(useful for calculating norms and reduced density matrices).
Returns:
A tuple containing:
node_dict:
A dictionary mapping the nodes to their copies.
edge_dict:
A dictionary mapping the edges to their copies.
"""
node_dict = {}
for node in nodes:
node_dict[node] = node.copy(conjugate)
edge_dict = {}
for edge in get_all_edges(nodes):
node1 = edge.node1
axis1 = edge.node1.get_axis_number(edge.axis1)
# edge dangling or node2 does not need to be copied
if edge.is_dangling() or edge.node2 not in node_dict:
new_edge = Edge(node_dict[node1], axis1, edge.name)
node_dict[node1].add_edge(new_edge, axis1)
edge_dict[edge] = new_edge
continue
node2 = edge.node2
axis2 = edge.node2.get_axis_number(edge.axis2)
# copy node2 but not node1
if node1 not in node_dict:
new_edge = Edge(node_dict[node2], axis2, edge.name)
node_dict[node2].add_edge(new_edge, axis2)
edge_dict[edge] = new_edge
continue
# both nodes should be copied
new_edge = Edge(node_dict[node1], axis1, edge.name, node_dict[node2], axis2)
new_edge.set_signature(edge.signature)
node_dict[node2].add_edge(new_edge, axis2)
node_dict[node1].add_edge(new_edge, axis1)
edge_dict[edge] = new_edge
return node_dict, edge_dict