# qiskit.providers.aer.extensions.snapshot_statevector のソースコード

# This code is part of Qiskit.
#
# (C) Copyright IBM 2018, 2019.
#
# obtain a copy of this license in the LICENSE.txt file in the root directory
#
# Any modifications or derivative works of this code must retain this
# copyright notice, and modified files need to carry a notice indicating
# that they have been altered from the originals.

"""
Simulator command to snapshot internal simulator representation.
"""
from warnings import warn
from qiskit import QuantumCircuit
from .snapshot import Snapshot

[ドキュメント]class SnapshotStatevector(Snapshot): """ Snapshot instruction for statevector snapshot type """
[ドキュメント] def __init__(self, label, num_qubits=0): """Create a statevector state snapshot instruction. Args: label (str): the snapshot label. num_qubits (int): the instruction barrier size [Default: 0]. Raises: ExtensionError: if snapshot is invalid. Additional Information: This snapshot is always performed on all qubits in a circuit. The number of qubits parameter specifies the size of the instruction as a barrier and should be set to the number of qubits in the circuit. .. note:: This instruction will be deprecated after the qiskit-aer 0.8 release. It has been superseded by the :class:qiskit.providers.aer.library.SaveStatevector instruction. """ warn('The SnapshotStatevector instruction will be deprecated in the' 'future. It has been superseded by the SaveStatevector' ' instructions.', PendingDeprecationWarning) super().__init__(label, snapshot_type='statevector', num_qubits=num_qubits)
def snapshot_statevector(self, label): """Take a statevector snapshot of the simulator state. Args: label (str): a snapshot label to report the result. Returns: QuantumCircuit: with attached instruction. Raises: ExtensionError: if snapshot is invalid. Additional Information: This snapshot is always performed on all qubits in a circuit. The number of qubits parameter specifies the size of the instruction as a barrier and should be set to the number of qubits in the circuit. .. note:: This method will be deprecated after the qiskit-aer 0.8 release. It has been superseded by the :func:qiskit.providers.aer.library.save_statevector circuit method. """ warn('The save_statevector circuit method will be deprecated in the' ' future. It has been superseded by the save_statevector' ' circuit method.', PendingDeprecationWarning) # Statevector snapshot acts as a barrier across all qubits in the # circuit snapshot_register = Snapshot.define_snapshot_register(self) return self.append( SnapshotStatevector(label, num_qubits=len(snapshot_register)), snapshot_register) QuantumCircuit.snapshot_statevector = snapshot_statevector