def _matrix_to_pauli_string_phasors(self,
mat: np.ndarray,
qubit: ops.Qid) -> ops.OP_TREE:
rotations = optimizers.single_qubit_matrix_to_pauli_rotations(
mat, self.atol)
out_ops = [] # type: List[ops.Operation]
for pauli, half_turns in rotations:
if (self.keep_clifford
and linalg.all_near_zero_mod(half_turns, 0.5)):
cliff_gate = ops.SingleQubitCliffordGate.from_quarter_turns(
pauli, round(half_turns * 2))
if out_ops and not isinstance(out_ops[-1],
ops.PauliStringPhasor):
op = cast(ops.GateOperation, out_ops[-1])
gate = cast(ops.SingleQubitCliffordGate, op.gate)
out_ops[-1] = gate.merged_with(cliff_gate)(qubit)
else:
out_ops.append(
cliff_gate(qubit))
else:
pauli_string = ops.PauliString.from_single(qubit, pauli)
out_ops.append(
ops.PauliStringPhasor(pauli_string,
exponent_neg=round(half_turns, 10)))
return out_ops
def _matrix_to_clifford_op(self, mat: np.ndarray, qubit: 'cirq.Qid') -> Optional[ops.Operation]:
rotations = optimizers.single_qubit_matrix_to_pauli_rotations(mat, self.atol)
clifford_gate = ops.SingleQubitCliffordGate.I
for pauli, half_turns in rotations:
if linalg.all_near_zero_mod(half_turns, 0.5):
clifford_gate = clifford_gate.merged_with(
self._rotation_to_clifford_gate(pauli, half_turns)
)
else:
return None
return clifford_gate(qubit)
def remove_negligible_strings(string_dag: circuitdag.CircuitDag,
atol=1e-8) -> None:
for node in tuple(string_dag.nodes()):
if linalg.all_near_zero_mod(node.val.exponent_relative, 2, atol=atol):
string_dag.remove_node(node)
def remove_negligible_strings(string_dag: circuits.CircuitDag,
atol=1e-8) -> None:
for node in tuple(string_dag.nodes()):
if linalg.all_near_zero_mod(node.val.half_turns, 2, atol=atol):
string_dag.remove_node(node)
