dwave.preprocessing.composites.SpinReversalTransformComposite.sample

SpinReversalTransformComposite.sample(bqm: dimod.binary.binary_quadratic_model.BinaryQuadraticModel, *, num_spin_reversal_transforms: int = 1, **kwargs)

Sample from the binary quadratic model.

Parameters

• bqm – Binary quadratic model to be sampled from.

• num_spin_reversal_transforms – Number of spin reversal transform runs. A value of 0 will not transform the problem. If you specify a nonzero value, each spin reversal transform will result in an independent run of the child sampler.

Returns

A sample set. Note that for a sampler that returns num_reads samples, the sample set will contain num_reads*num_spin_reversal_transforms samples.

Examples

This example runs 100 spin reversals applied to one variable of a QUBO problem.

>>> from dimod import ExactSolver
>>> from dwave.preprocessing.composites import SpinReversalTransformComposite
>>> base_sampler = ExactSolver()
>>> composed_sampler = SpinReversalTransformComposite(base_sampler)
...
>>> Q = {('a', 'a'): -1, ('b', 'b'): -1, ('a', 'b'): 2}
>>> response = composed_sampler.sample_qubo(Q,
...               num_spin_reversal_transforms=100)
>>> len(response)
400