def test_iadd_number(self):
qm = QuadraticModel()
original = qm
qm += 1
self.assertIs(qm, original)
self.assertEqual(qm.offset, 1)
self.assertEqual(qm.num_variables, 0)
def test_radd_number(self):
qm = QuadraticModel()
new = 1 + qm
self.assertIsNot(qm, new)
self.assertEqual(qm.offset, 0)
self.assertEqual(new.offset, 1)
self.assertEqual(qm.num_variables, 0)
self.assertEqual(new.num_variables, 0)
def test(self, _, BQM):
for vartype in ['SPIN', 'BINARY']:
with self.subTest(vartype):
bqm = BQM({'a': 1}, {'ab': 2, 'bc': 3}, 4, vartype)
qm = QuadraticModel.from_bqm(bqm)
self.assertEqual(bqm.linear, qm.linear)
self.assertEqual(bqm.quadratic, qm.quadratic)
self.assertEqual(bqm.offset, qm.offset)
for v in bqm.variables:
self.assertIs(qm.vartype(v), bqm.vartype)
def build_knapsack_cqm(costs, weights, max_weight):
"""Construct a CQM for the knapsack problem.
Args:
costs (array-like):
Array of costs for the items.
weights (array-like):
Array of weights for the items.
max_weight (int):
Maximum allowable weight for the knapsack.
Returns:
Constrained quadratic model instance that represents the knapsack problem.
"""
num_items = len(costs)
print("\nBuilding a CQM for {} items.".format(str(num_items)))
cqm = ConstrainedQuadraticModel()
obj = BinaryQuadraticModel(vartype='BINARY')
constraint = QuadraticModel()
for i in range(num_items):
# Objective is to maximize the total costs
obj.add_variable(i)
obj.set_linear(i, -costs[i])
# Constraint is to keep the sum of items' weights under or equal capacity
constraint.add_variable('BINARY', i)
constraint.set_linear(i, weights[i])
cqm.set_objective(obj)
cqm.add_constraint(constraint, sense="<=", rhs=max_weight, label='capacity')
return cqm
def test_set_upper_bound(self, dtype):
qm = QuadraticModel(dtype=dtype)
qm.add_variable('INTEGER', 'i')
qm.add_variable('SPIN', 's')
qm.add_variable('BINARY', 'x')
# cannot set less than max_integer
with self.assertRaises(ValueError):
qm.set_upper_bound('i', np.finfo(dtype).max)
# cannot set for non-integer
with self.assertRaises(ValueError):
qm.set_upper_bound('s', -2)
with self.assertRaises(ValueError):
qm.set_upper_bound('x', 10)
# cannot set one less than the current lower bound
with self.assertRaises(ValueError):
qm.set_upper_bound('i', qm.lower_bound('i') - 1)
qm.set_upper_bound('i', 10)
self.assertEqual(qm.upper_bound('i'), 10)
qm.set_upper_bound('i', 11.3)
self.assertEqual(qm.upper_bound('i'), 11)