DAGCircuit

class DAGCircuit

Bases: object

Quantum circuit as a directed acyclic graph.

There are 3 types of nodes in the graph: inputs, outputs, and operations. The nodes are connected by directed edges that correspond to qubits and bits.

Create an empty circuit.

Methods

add_calibration	Register a low-level, custom pulse definition for the given gate.
add_clbits	Add individual clbit wires.
add_creg	Add all wires in a classical register.
add_qreg	Add all wires in a quantum register.
add_qubits	Add individual qubit wires.
ancestors	Returns set of the ancestors of a node as DAGOpNodes and DAGInNodes.
apply_operation_back	Apply an operation to the output of the circuit.
apply_operation_front	Apply an operation to the input of the circuit.
bfs_successors	Returns an iterator of tuples of (DAGNode, [DAGNodes]) where the DAGNode is the current node and [DAGNode] is its successors in BFS order.
collect_1q_runs	Return a set of non-conditional runs of 1q "op" nodes.
collect_2q_runs	Return a set of non-conditional runs of 2q "op" nodes.
collect_runs	Return a set of non-conditional runs of "op" nodes with the given names.
compose	Compose the other circuit onto the output of this circuit.
copy_empty_like	Return a copy of self with the same structure but empty.
count_ops	Count the occurrences of operation names.
count_ops_longest_path	Count the occurrences of operation names on the longest path.
depth	Return the circuit depth.
descendants	Returns set of the descendants of a node as DAGOpNodes and DAGOutNodes.
draw	Draws the dag circuit.
edges	Iterator for edge values and source and dest node
front_layer	Return a list of op nodes in the first layer of this dag.
gate_nodes	Get the list of gate nodes in the dag.
has_calibration_for	Return True if the dag has a calibration defined for the node operation.
idle_wires	Return idle wires.
is_predecessor	Checks if a second node is in the predecessors of node.
is_successor	Checks if a second node is in the successors of node.
layers	Yield a shallow view on a layer of this DAGCircuit for all d layers of this circuit.
longest_path	Returns the longest path in the dag as a list of DAGOpNodes, DAGInNodes, and DAGOutNodes.
multi_qubit_ops	Get list of 3+ qubit operations.
multigraph_layers	Yield layers of the multigraph.
named_nodes	Get the set of "op" nodes with the given name.
node	Get the node in the dag.
nodes	Iterator for node values.
nodes_on_wire	Iterator for nodes that affect a given wire.
num_clbits	Return the total number of classical bits used by the circuit.
num_qubits	Return the total number of qubits used by the circuit.
num_tensor_factors	Compute how many components the circuit can decompose into.
op_nodes	Get the list of "op" nodes in the dag.
predecessors	Returns iterator of the predecessors of a node as DAGOpNodes and DAGInNodes.
properties	Return a dictionary of circuit properties.
quantum_predecessors	Returns iterator of the predecessors of a node that are connected by a quantum edge as DAGOpNodes and DAGInNodes.
quantum_successors	Returns iterator of the successors of a node that are connected by a quantum edge as Opnodes and DAGOutNodes.
remove_all_ops_named	Remove all operation nodes with the given name.
remove_ancestors_of	Remove all of the ancestor operation nodes of node.
remove_clbits	Remove classical bits from the circuit.
remove_cregs	Remove classical registers from the circuit, leaving underlying bits in place.
remove_descendants_of	Remove all of the descendant operation nodes of node.
remove_nonancestors_of	Remove all of the non-ancestors operation nodes of node.
remove_nondescendants_of	Remove all of the non-descendants operation nodes of node.
remove_op_node	Remove an operation node n.
remove_qregs	Remove classical registers from the circuit, leaving underlying bits in place.
remove_qubits	Remove quantum bits from the circuit.
replace_block_with_op	Replace a block of nodes with a single node.
reverse_ops	Reverse the operations in the self circuit.
serial_layers	Yield a layer for all gates of this circuit.
size	Return the number of operations.
substitute_node	Replace an DAGOpNode with a single operation.
substitute_node_with_dag	Replace one node with dag.
successors	Returns iterator of the successors of a node as DAGOpNodes and DAGOutNodes.
swap_nodes	Swap connected nodes e.g.
topological_nodes	Yield nodes in topological order.
topological_op_nodes	Yield op nodes in topological order.
two_qubit_ops	Get list of 2 qubit operations.
width	Return the total number of qubits + clbits used by the circuit.

Attributes

calibrations

Return calibration dictionary.

The custom pulse definition of a given gate is of the form

{'gate_name': {(qubits, params): schedule}}

global_phase

Return the global phase of the circuit.

node_counter

Returns the number of nodes in the dag.

wires

Return a list of the wires in order.