Handle exception when BQM is passed to DQM sampler

dwavesystems · Feb 28, 2022 · dc53ec4 · dc53ec4
1 parent 4fa4b27
commit dc53ec4
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Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/dwave/system/samplers/leap_hybrid_sampler.py b/dwave/system/samplers/leap_hybrid_sampler.py
@@ -533,8 +533,12 @@ def min_time_limit(self, dqm):
             first two pairs that represent problems with "density" between 1 to
             100).
         """
-        ec = (dqm.num_variable_interactions() * dqm.num_cases() /
-              max(dqm.num_variables(), 1))
+        from dimod.discrete.discrete_quadratic_model import DiscreteQuadraticModel
+        if isinstance(dqm, DiscreteQuadraticModel):
+            ec = (dqm.num_variable_interactions() * dqm.num_cases() /
+                max(dqm.num_variables(), 1))
+        else:
+            raise TypeError(f"Expecting DiscreteQuadraticModel object, got {type(dqm)}")
         limits = np.array(self.properties['minimum_time_limit'])
         t = np.interp(ec, limits[:, 0], limits[:, 1])
         return max([5, t])

diff --git a/tests/test_leaphybriddqmsolver.py b/tests/test_leaphybriddqmsolver.py
@@ -54,13 +54,17 @@ def get_solver(self, *args, **kwargs):
             sampler = LeapHybridDQMSampler()
 
             dqm = dimod.DQM()
+            bqm = dimod.BinaryQuadraticModel('SPIN')
 
         with self.assertRaises(ValueError):
             sampler.sample_dqm(dqm, time_limit=1)
 
         with self.assertRaises(ValueError):
             sampler.sample_dqm(dqm, time_limit=10000000)
 
+        with self.assertRaises(TypeError):
+            sampler.sample_dqm(bqm)
+
     def test_DQM_subclass_without_serialization_can_be_sampled(self):
         """Test that DQM subclasses that do not implement serialization can
         still be sampled by LeapHybridDQMSampler.