def circuit_to_gate(circuit, parameter_map=None): """Build a ``Gate`` object from a ``QuantumCircuit``. The gate is anonymous (not tied to a named quantum register), and so can be inserted into another circuit. The gate will have the same string name as the circuit. Args: circuit (QuantumCircuit): the input circuit. parameter_map (dict): For parameterized circuits, a mapping from parameters in the circuit to parameters to be used in the gate. If None, existing circuit parameters will also parameterize the Gate. Raises: QiskitError: if circuit is non-unitary or if parameter_map is not compatible with circuit Return: Gate: a Gate equivalent to the action of the input circuit. Upon decomposition, this gate will yield the components comprising the original circuit. """ if circuit.clbits: raise QiskitError('Circuit with classical bits cannot be converted ' 'to gate.') for inst, _, _ in circuit.data: if not isinstance(inst, Gate): raise QiskitError( ('One or more instructions cannot be converted to' ' a gate. "{}" is not a gate instruction').format(inst.name)) if parameter_map is None: parameter_dict = {p: p for p in circuit.parameters} else: parameter_dict = circuit._unroll_param_dict(parameter_map) if parameter_dict.keys() != circuit.parameters: raise QiskitError(('parameter_map should map all circuit parameters. ' 'Circuit parameters: {}, parameter_map: {}').format( circuit.parameters, parameter_dict)) gate = Gate(name=circuit.name, num_qubits=sum([qreg.size for qreg in circuit.qregs]), params=sorted(parameter_dict.values(), key=lambda p: p.name)) gate.condition = None def find_bit_position(bit): """find the index of a given bit (Register, int) within a flat ordered list of bits of the circuit """ if isinstance(bit, Qubit): ordered_regs = circuit.qregs else: ordered_regs = circuit.cregs reg_index = ordered_regs.index(bit.register) return sum([reg.size for reg in ordered_regs[:reg_index]]) + bit.index target = circuit.assign_parameters(parameter_dict, inplace=False) # pylint: disable=cyclic-import from qiskit.circuit.equivalence_library import SessionEquivalenceLibrary as sel # pylint: enable=cyclic-import sel.add_equivalence(gate, target) definition = target.data if gate.num_qubits > 0: q = QuantumRegister(gate.num_qubits, 'q') # The 3rd parameter in the output tuple) is hard coded to [] because # Gate objects do not have cregs set and we've verified that all # instructions are gates definition = list( map( lambda x: (x[0], list(map(lambda y: q[find_bit_position(y)], x[1])), []), definition)) gate.definition = definition return gate
def add_decomposition(self, decomposition): """Add a decomposition of the instruction to the SessionEquivalenceLibrary.""" # pylint: disable=cyclic-import from qiskit.circuit.equivalence_library import SessionEquivalenceLibrary as sel sel.add_equivalence(self, decomposition)
def circuit_to_instruction(circuit, parameter_map=None): """Build an ``Instruction`` object from a ``QuantumCircuit``. The instruction is anonymous (not tied to a named quantum register), and so can be inserted into another circuit. The instruction will have the same string name as the circuit. Args: circuit (QuantumCircuit): the input circuit. parameter_map (dict): For parameterized circuits, a mapping from parameters in the circuit to parameters to be used in the instruction. If None, existing circuit parameters will also parameterize the instruction. Raises: QiskitError: if parameter_map is not compatible with circuit Return: qiskit.circuit.Instruction: an instruction equivalent to the action of the input circuit. Upon decomposition, this instruction will yield the components comprising the original circuit. Example: .. jupyter-execute:: from qiskit import QuantumRegister, ClassicalRegister, QuantumCircuit from qiskit.converters import circuit_to_instruction %matplotlib inline q = QuantumRegister(3, 'q') c = ClassicalRegister(3, 'c') circ = QuantumCircuit(q, c) circ.h(q[0]) circ.cx(q[0], q[1]) circ.measure(q[0], c[0]) circ.rz(0.5, q[1]).c_if(c, 2) circuit_to_instruction(circ) """ if parameter_map is None: parameter_dict = {p: p for p in circuit.parameters} else: parameter_dict = circuit._unroll_param_dict(parameter_map) if parameter_dict.keys() != circuit.parameters: raise QiskitError(('parameter_map should map all circuit parameters. ' 'Circuit parameters: {}, parameter_map: {}').format( circuit.parameters, parameter_dict)) instruction = Instruction( name=circuit.name, num_qubits=sum([qreg.size for qreg in circuit.qregs]), num_clbits=sum([creg.size for creg in circuit.cregs]), params=sorted(parameter_dict.values(), key=lambda p: p.name)) instruction.condition = None def find_bit_position(bit): """find the index of a given bit (Register, int) within a flat ordered list of bits of the circuit """ if isinstance(bit, Qubit): ordered_regs = circuit.qregs else: ordered_regs = circuit.cregs reg_index = ordered_regs.index(bit.register) return sum([reg.size for reg in ordered_regs[:reg_index]]) + bit.index target = circuit.copy() target._substitute_parameters(parameter_dict) # pylint: disable=cyclic-import from qiskit.circuit.equivalence_library import SessionEquivalenceLibrary as sel # pylint: enable=cyclic-import sel.add_equivalence(instruction, target) definition = target.data if instruction.num_qubits > 0: q = QuantumRegister(instruction.num_qubits, 'q') if instruction.num_clbits > 0: c = ClassicalRegister(instruction.num_clbits, 'c') definition = list( map( lambda x: (x[0], list(map(lambda y: q[find_bit_position(y)], x[1])), list(map(lambda y: c[find_bit_position(y)], x[2]))), definition)) instruction.definition = definition return instruction