def test_sample_instantiation(self):
# Check that graph related values have not been instantiated
sampler = LazyFixedEmbeddingComposite(MockDWaveSampler())
self.assertIsNone(sampler.embedding)
self.assertIsNone(sampler.nodelist)
self.assertIsNone(sampler.edgelist)
self.assertIsNone(sampler.adjacency)
# Set up an and_gate BQM and sample
Q = {
('a', 'a'): 0.0,
('c', 'c'): 6.0,
('b', 'b'): 0.0,
('b', 'a'): 2.0,
('c', 'a'): -4.0,
('c', 'b'): -4.0
}
sampler.sample_qubo(Q)
# Check that values have been populated
self.assertIsNotNone(sampler.embedding)
self.assertEqual(sampler.nodelist, ['a', 'b', 'c'])
self.assertEqual(sampler.edgelist, [('a', 'b'), ('a', 'c'),
('b', 'c')])
self.assertEqual(sampler.adjacency, {
'a': {'b', 'c'},
'b': {'a', 'c'},
'c': {'a', 'b'}
})
def test_same_embedding(self):
sampler = LazyFixedEmbeddingComposite(MockDWaveSampler())
# Set up Ising and sample
h = {'a': 1, 'b': 1, 'c': 1}
J = {('a', 'b'): 3, ('b', 'c'): -2, ('a', 'c'): 1}
sampler.sample_ising(h, J)
# Store embedding
prev_embedding = sampler.embedding
# Set up QUBO of an or_gate
Q = {('a', 'a'): 2.0, ('c', 'c'): 2.0, ('b', 'b'): 2.0, ('b', 'a'): 2.0, ('c', 'a'): -4.0, ('c', 'b'): -4.0}
sampler.sample_qubo(Q)
# Check that the same embedding is used
self.assertEqual(sampler.embedding, prev_embedding)
def test_sparse_qubo(self):
# There is no relationship between nodes 2 and 3
Q = {(1, 1): 1, (2, 2): 2, (3, 3): 3, (1, 2): 4, (1, 3): 6}
sampler = LazyFixedEmbeddingComposite(MockDWaveSampler())
response = sampler.sample_qubo(Q)
# Check embedding
self.assertIsNotNone(sampler.embedding)
self.assertEqual(sampler.nodelist, [1, 2, 3])
self.assertEqual(sampler.edgelist, [(1, 2), (1, 3)])
# Check that at least one response was found
self.assertGreaterEqual(len(response), 1)
def test_qubo(self):
Q = {(1, 1): 1, (2, 2): 2, (3, 3): 3, (1, 2): 4, (2, 3): 5, (1, 3): 6}
sampler = LazyFixedEmbeddingComposite(MockDWaveSampler())
response = sampler.sample_qubo(Q)
# Check embedding
self.assertIsNotNone(sampler.embedding)
self.assertEqual(sampler.nodelist, [1, 2, 3])
self.assertEqual(sampler.edgelist, [(1, 2), (1, 3), (2, 3)])
self.assertEqual(sampler.adjacency, {1: {2, 3}, 2: {1, 3}, 3: {1, 2}})
# Check that at least one response was found
self.assertGreaterEqual(len(response), 1)
# Copyright 2020 D-Wave Systems, Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
from dwave.system.samplers import DWaveSampler
from dwave.system.composites import LazyFixedEmbeddingComposite
# Set up the QUBO. Start with the equations from the slides:
chainstrength = 4
numruns = 100
Q = {(0, 0): 2, (0, 1): -2, (0, 2): -2, (1, 2): 2}
sampler = LazyFixedEmbeddingComposite(DWaveSampler())
response = sampler.sample_qubo(Q,
chain_strength=chainstrength,
num_reads=numruns)
print(sampler.properties['embedding'])
for smpl, energy in response.data(['sample', 'energy']):
print(smpl, energy)