# -*- coding: utf-8 -*-
# This code is part of Qiskit.
#
# (C) Copyright IBM 2020.
#
# 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.
""" EvolutionBase Class """
import logging
from ..operator_base import OperatorBase
from ..converters.converter_base import ConverterBase
logger = logging.getLogger(__name__)
[docs]class EvolutionBase(ConverterBase):
r"""
A base for Evolution converters.
Evolutions are converters which traverse an Operator tree, replacing any ``EvolvedOp`` `e`
with a Schrodinger equation-style evolution ``CircuitOp`` equalling or approximating the
matrix exponential of -i * the Operator contained inside (`e.primitive`). The Evolutions are
essentially implementations of Hamiltonian Simulation algorithms, including various methods
for Trotterization.
"""
[docs] def convert(self, operator: OperatorBase) -> OperatorBase:
""" Traverse the operator, replacing any ``EvolutionOps`` with their equivalent evolution
``CircuitOps``.
Args:
operator: The Operator to convert.
Returns:
The converted Operator, with ``EvolutionOps`` replaced by ``CircuitOps``.
"""
raise NotImplementedError
# TODO @abstractmethod
# def error_bounds(self):
# """ error bounds """
# raise NotImplementedError