def permute(self, permutation: List[int]) -> 'VectorStateFn':
new_self = self
new_num_qubits = max(permutation) + 1
if self.num_qubits != len(permutation):
# raise OpflowError("New index must be defined for each qubit of the operator.")
pass
if self.num_qubits < new_num_qubits:
# pad the operator with identities
new_self = self._expand_dim(new_num_qubits - self.num_qubits)
qc = QuantumCircuit(new_num_qubits)
# extend the permutation indices to match the size of the new matrix
permutation \
= list(filter(lambda x: x not in permutation, range(new_num_qubits))) + permutation
# decompose permutation into sequence of transpositions
transpositions = arithmetic.transpositions(permutation)
for trans in transpositions:
qc.swap(trans[0], trans[1])
from .. import CircuitOp
matrix = CircuitOp(qc).to_matrix()
vector = new_self.primitive.data
return VectorStateFn(primitive=matrix.dot(vector),
coeff=self.coeff,
is_measurement=self.is_measurement)
def permute(self, permutation: Optional[List[int]] = None) -> 'MatrixOp':
"""Creates a new MatrixOp that acts on the permuted qubits.
Args:
permutation: A list defining where each qubit should be permuted. The qubit at index
j should be permuted to position permutation[j].
Returns:
A new MatrixOp representing the permuted operator.
Raises:
OpflowError: if indices do not define a new index for each qubit.
"""
new_self = self
new_matrix_size = max(permutation) + 1
if self.num_qubits != len(permutation):
raise OpflowError(
"New index must be defined for each qubit of the operator.")
if self.num_qubits < new_matrix_size:
# pad the operator with identities
new_self = self._expand_dim(new_matrix_size - self.num_qubits)
qc = QuantumCircuit(new_matrix_size)
# extend the indices to match the size of the new matrix
permutation \
= list(filter(lambda x: x not in permutation, range(new_matrix_size))) + permutation
# decompose permutation into sequence of transpositions
transpositions = arithmetic.transpositions(permutation)
for trans in transpositions:
qc.swap(trans[0], trans[1])
matrix = CircuitOp(qc).to_matrix()
return MatrixOp(matrix.transpose()) @ new_self @ MatrixOp(
matrix) # type: ignore
def permute(self, permutation: List[int]) -> "OperatorBase":
"""Permute the qubits of the operator.
Args:
permutation: A list defining where each qubit should be permuted. The qubit at index
j should be permuted to position permutation[j].
Returns:
A new ListOp representing the permuted operator.
Raises:
OpflowError: if indices do not define a new index for each qubit.
"""
new_self = self
circuit_size = max(permutation) + 1
try:
if self.num_qubits != len(permutation):
raise OpflowError(
"New index must be defined for each qubit of the operator."
)
except ValueError:
raise OpflowError(
"Permute is only possible if all operators in the ListOp have the "
"same number of qubits.") from ValueError
if self.num_qubits < circuit_size:
# pad the operator with identities
new_self = self._expand_dim(circuit_size - self.num_qubits)
qc = QuantumCircuit(circuit_size)
# extend the indices to match the size of the circuit
permutation = (
list(filter(lambda x: x not in permutation, range(circuit_size))) +
permutation)
# decompose permutation into sequence of transpositions
transpositions = arithmetic.transpositions(permutation)
for trans in transpositions:
qc.swap(trans[0], trans[1])
# pylint: disable=cyclic-import
from ..primitive_ops.circuit_op import CircuitOp
return CircuitOp(qc.reverse_ops()) @ new_self @ CircuitOp(qc)
