def dag_to_circuit(dag):
"""Build a ``QuantumCircuit`` object from a ``DAGCircuit``.
Args:
dag (DAGCircuit): the input dag.
Return:
QuantumCircuit: the circuit representing the input dag.
"""
circuit = QuantumCircuit()
random_name = QuantumCircuit.cls_prefix() + \
str(''.join(random.choice(string.ascii_lowercase) for i in range(8)))
circuit.name = dag.name or random_name
for qreg in dag.qregs.values():
circuit.add_register(qreg)
for creg in dag.cregs.values():
circuit.add_register(creg)
graph = dag.multi_graph
for node in nx.topological_sort(graph):
n = graph.nodes[node]
if n['type'] == 'op':
op = deepcopy(n['op'])
op.qargs = n['qargs']
op.cargs = n['cargs']
op.circuit = circuit
if 'condition' in n and n['condition']:
op = op.c_if(*n['condition'])
circuit._attach(op)
return circuit
def dag_to_circuit(dag):
"""Build a ``QuantumCircuit`` object from a ``DAGCircuit``.
Args:
dag (DAGCircuit): the input dag.
Return:
QuantumCircuit: the circuit representing the input dag.
"""
qregs = collections.OrderedDict()
for qreg in dag.qregs.values():
qreg_tmp = QuantumRegister(qreg.size, name=qreg.name)
qregs[qreg.name] = qreg_tmp
cregs = collections.OrderedDict()
for creg in dag.cregs.values():
creg_tmp = ClassicalRegister(creg.size, name=creg.name)
cregs[creg.name] = creg_tmp
name = dag.name or None
circuit = QuantumCircuit(*qregs.values(), *cregs.values(), name=name)
for node in dag.node_nums_in_topological_order():
n = dag.node(node)
if n['type'] == 'op':
qubits = []
for qubit in n['qargs']:
qubits.append(qregs[qubit[0].name][qubit[1]])
clbits = []
for clbit in n['cargs']:
clbits.append(cregs[clbit[0].name][clbit[1]])
# Get arguments for classical control (if any)
if n['condition'] is None:
control = None
else:
control = (n['condition'][0], n['condition'][1])
def duplicate_instruction(inst):
"""Create a fresh instruction from an input instruction."""
if inst.name == 'barrier':
params = [inst.qargs]
elif inst.name == 'snapshot':
params = inst.params + [inst.qargs]
else:
params = inst.params + inst.qargs + inst.cargs
new_inst = inst.__class__(*params)
return new_inst
inst = duplicate_instruction(n['op'])
inst.control = control
circuit._attach(inst)
return circuit
