qml.transforms.CommutationDAG¶
-
class
CommutationDAG(tape)[source]¶ Bases:
objectClass to represent a quantum circuit as a directed acyclic graph (DAG). This class is useful to build the commutation DAG and set up all nodes attributes. The construction of the DAG should be used through the transform
qml.transforms.commutation_dag.- Parameters
tape (QuantumTape) – PennyLane quantum tape representing a quantum circuit.
Reference:
[1] Iten, R., Moyard, R., Metger, T., Sutter, D. and Woerner, S., 2020. Exact and practical pattern matching for quantum circuit optimization. doi.org/10.1145/3498325
Attributes
Return the DAG object.
Return the size of the DAG object.
-
graph¶ Return the DAG object.
- Returns
Networkx representation of the DAG.
- Return type
networkx.MultiDiGraph()
-
size¶ Return the size of the DAG object.
- Returns
Number of nodes in the DAG.
- Return type
int
Methods
add_edge(node_in, node_out)Add an edge (non commutation) between node_in and node_out.
add_node(operation)Add the operation as a node in the DAG and updates the edges.
direct_predecessors(node_id)Return the direct predecessors of the given node.
direct_successors(node_id)Return the direct successors of the given node.
draw([filename])Draw the DAG object.
get_edge(node_in, node_out)Get the edge between two nodes if it exists.
Get all edges as an iterable.
get_node(node_id)Add the operation as a node in the DAG and updates the edges.
Return iterable to loop through all the nodes in the DAG.
predecessors(node_id)Return the predecessors of the given node.
successors(node_id)Return the successors of the given node.
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add_edge(node_in, node_out)[source]¶ Add an edge (non commutation) between node_in and node_out.
- Parameters
node_in (int) – Id of the ingoing node.
node_out (int) – Id of the outgoing node.
- Returns
Id of the created edge.
- Return type
int
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add_node(operation)[source]¶ Add the operation as a node in the DAG and updates the edges.
- Parameters
operation (qml.operation) – PennyLane quantum operation to add to the DAG.
-
direct_predecessors(node_id)[source]¶ Return the direct predecessors of the given node.
- Parameters
node_id (int) – Id of the node in the DAG.
- Returns
List of the direct predecessors of the given node.
- Return type
list[int]
-
direct_successors(node_id)[source]¶ Return the direct successors of the given node.
- Parameters
node_id (int) – Id of the node in the DAG.
- Returns
List of the direct successors of the given node.
- Return type
list[int]
-
draw(filename='dag.png')[source]¶ Draw the DAG object.
- Parameters
filename (str) – The file name which is in PNG format. Default = ‘dag.png’
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get_edge(node_in, node_out)[source]¶ Get the edge between two nodes if it exists.
- Parameters
node_in (int) – Id of the ingoing node.
node_out (int) – Id of the outgoing node.
- Returns
Default weight is 0, it returns None when there is no edge.
- Return type
dict or None
-
get_edges()[source]¶ Get all edges as an iterable.
- Returns
Iterable over all edges.
- Return type
networkx.classes.reportviews.OutMultiEdgeDataView
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get_node(node_id)[source]¶ Add the operation as a node in the DAG and updates the edges.
- Parameters
node_id (int) – PennyLane quantum operation to add to the DAG.
- Returns
The node with the given id.
- Return type
CommutationDAGNOde
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get_nodes()[source]¶ Return iterable to loop through all the nodes in the DAG.
- Returns
Iterable nodes.
- Return type
networkx.classes.reportviews.NodeDataView