# Código fonte de qiskit.algorithms.eigen_solvers.eigen_solver

```
# This code is part of Qiskit.
#
# (C) Copyright IBM 2020, 2022.
#
# This code is licensed under the Apache License, Version 2.0. You may
# obtain a copy of this license in the LICENSE.txt file in the root directory
# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
#
# 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.
"""The Eigensolver interface"""
from abc import ABC, abstractmethod
from typing import Optional, List, Tuple
import numpy as np
from qiskit.opflow import OperatorBase
from qiskit.utils.deprecation import deprecate_function
from ..algorithm_result import AlgorithmResult
from ..list_or_dict import ListOrDict
[documentos]class Eigensolver(ABC):
"""Pending deprecation: Eigensolver Interface.
The Eigensolver interface has been superseded by the
:class:`qiskit.algorithms.eigensolvers.Eigensolver` interface.
This interface will be deprecated in a future release and subsequently
removed after that.
Algorithms that can compute eigenvalues for an operator
may implement this interface to allow different algorithms to be
used interchangeably.
"""
@deprecate_function(
"The Eigensolver interface has been superseded by the "
"qiskit.algorithms.eigensolvers.Eigensolver interface. "
"This interface will be deprecated in a future release and subsequently "
"removed after that.",
category=PendingDeprecationWarning,
)
def __init__(self) -> None:
pass
[documentos] @abstractmethod
def compute_eigenvalues(
self, operator: OperatorBase, aux_operators: Optional[ListOrDict[OperatorBase]] = None
) -> "EigensolverResult":
"""
Computes eigenvalues. Operator and aux_operators can be supplied here and
if not None will override any already set into algorithm so it can be reused with
different operators. While an operator is required by algorithms, aux_operators
are optional. To 'remove' a previous aux_operators array use an empty list here.
Args:
operator: Qubit operator of the Observable
aux_operators: Optional list of auxiliary operators to be evaluated with the
eigenstate of the minimum eigenvalue main result and their expectation values
returned. For instance in chemistry these can be dipole operators, total particle
count operators so we can get values for these at the ground state.
Returns:
EigensolverResult
"""
return EigensolverResult()
[documentos] @classmethod
def supports_aux_operators(cls) -> bool:
"""Whether computing the expectation value of auxiliary operators is supported.
Returns:
True if aux_operator expectations can be evaluated, False otherwise
"""
return False
[documentos]class EigensolverResult(AlgorithmResult):
"""Pending deprecation: Eigensolver Result.
The EigensolverResult class has been superseded by the
:class:`qiskit.algorithms.eigensolvers.EigensolverResult` class.
This class will be deprecated in a future release and subsequently
removed after that.
"""
@deprecate_function(
"The EigensolverResult class has been superseded by the "
"qiskit.algorithms.eigensolvers.EigensolverResult class. "
"This class will be deprecated in a future release and subsequently "
"removed after that.",
category=PendingDeprecationWarning,
)
def __init__(self) -> None:
super().__init__()
self._eigenvalues = None
self._eigenstates = None
self._aux_operator_eigenvalues = None
@property
def eigenvalues(self) -> Optional[np.ndarray]:
"""returns eigen values"""
return self._eigenvalues
@eigenvalues.setter
def eigenvalues(self, value: np.ndarray) -> None:
"""set eigen values"""
self._eigenvalues = value
@property
def eigenstates(self) -> Optional[np.ndarray]:
"""return eigen states"""
return self._eigenstates
@eigenstates.setter
def eigenstates(self, value: np.ndarray) -> None:
"""set eigen states"""
self._eigenstates = value
@property
def aux_operator_eigenvalues(self) -> Optional[List[ListOrDict[Tuple[complex, complex]]]]:
"""Return aux operator expectation values.
These values are in fact tuples formatted as (mean, standard deviation).
"""
return self._aux_operator_eigenvalues
@aux_operator_eigenvalues.setter
def aux_operator_eigenvalues(self, value: List[ListOrDict[Tuple[complex, complex]]]) -> None:
"""set aux operator eigen values"""
self._aux_operator_eigenvalues = value
```