Class StructuredSolver

dwave/cloud/solver.py:1042–1772

Class for D-Wave structured solvers. This class provides :term:`Ising`, :term:`QUBO` and :term:`BQM` sampling methods and encapsulates the solver description returned from the D-Wave cloud API. Args: client (:class:`~dwave.cloud.client.Client`): Client that mana

class StructuredSolver(BaseSolver):
    """Class for D-Wave structured solvers.

    This class provides :term:`Ising`, :term:`QUBO` and :term:`BQM` sampling
    methods and encapsulates the solver description returned from the D-Wave
    cloud API.

    Args:
        client (:class:`~dwave.cloud.client.Client`):
            Client that manages access to this solver.

        data (`dict`):
            Data from the server describing this solver.
    """

    _handled_problem_types = {"ising", "qubo"}
    _handled_encoding_formats = {"qp"}

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        # The exact sequence of nodes/edges is used in encoding problems and must be preserved
        try:
            self._encoding_qubits = self.properties['qubits']
        except KeyError:
            raise SolverPropertyMissingError("Missing solver property: 'properties.qubits'")

        if 'couplers' not in self.properties:
            raise SolverPropertyMissingError("Missing solver property: 'properties.couplers'")

        # Create a set of default parameters for the queries
        self._params = {}

        # Add derived properties specific for this solver class
        self.derived_properties.update({'lower_noise', 'num_active_qubits', 'version', 'graph_id'})

    def __repr__(self):
        return f"{type(self).__name__}(name={self.name!r}, graph_id={self.graph_id!r})"

    # Derived properties

    @property
    def version(self) -> dict:
        """QPU solver version dict (contains at least ``graph_id``). Returns
        an empty dict for non-QPU solvers."""
        return v.model_dump() if (v := self.identity.version) else {}

    @property
    def graph_id(self) -> Optional[str]:
        """QPU solver working graph id. Returns ``None`` for non-QPU solvers."""
        return self.version.get('graph_id')

    @property
    def num_active_qubits(self):
        "The number of active (encoding) qubits."
        return len(self.nodes)

    @property