dwave.samplers.PlanarGraphSolver.sample¶

PlanarGraphSolver.sample(bqm: dimod.binary.binary_quadratic_model.BinaryQuadraticModel, pos: Optional[Mapping[Hashable, Tuple[float, float]]] = None, **kwargs) → dimod.sampleset.SampleSet[source]¶

Find a ground state of a planar Ising problem without linear biases.

Parameters

bqm – Binary quadratic model representing a planar Ising model with no linear biases.
pos – Position for each node as a dict of form {node: (x-coordinate, y-coordinate),...}.

Examples

>>> import dimod
>>> from dwave.samplers.planar import PlanarGraphSolver
>>> bqm = dimod.BinaryQuadraticModel.empty(dimod.SPIN)
>>> bqm.add_interaction('a', 'b', +1.0)
>>> bqm.add_interaction('b', 'c', +1.0)
>>> bqm.add_interaction('c', 'a', +1.0)
>>> pos = {'a': (0, 0), 'b': (1, 0), 'c': (0, 1)}
>>> sample = PlanarGraphSolver().sample(bqm, pos)
>>> sample.first
Sample(sample={'a': 1, 'b': -1, 'c': -1}, energy=-1.0, num_occurrences=1)