def test_parse_non_expanded_quadratic_expression(self):
x, y, z = self.vars[:3]
offset = 5
expr = (x + y)**2 - (z - 2)**2 + offset
target = {
frozenset([x]): 1,
frozenset([y]): 1,
frozenset([x, y]): 2,
frozenset([z]): -1
}
linear_target = {z: 4}
constraint = Constraint(expr, lb=0)
offset_const, linear_terms_const, quad_terms_const = parse_optimization_expression(
constraint, quadratic=True)
offset_obj, linear_terms_obj, quad_terms_obj = parse_optimization_expression(
Objective(expr), expression=expr, linear=False)
self.assertEqual(offset_const - constraint.lb, -4 + offset)
self.assertEqual(offset_obj, -4 + offset)
_compare_term_dicts(self, linear_terms_const, linear_target)
_compare_term_dicts(self, linear_terms_obj, linear_target)
_compare_term_dicts(self, quad_terms_const, target)
_compare_term_dicts(self, quad_terms_obj, target)
def setUp(self):
self.model = Model()
x = Variable('x', lb=0, ub=10)
y = Variable('y', lb=0, ub=10)
constr = Constraint(1. * x + y, lb=3, name="constr1")
obj = Objective(2 * x + y)
self.model.add(x)
self.model.add(y)
self.model.add(constr)
self.model.objective = obj
def test_parse_linear_expression(self):
x, y, z = self.vars[:3]
expr = 1 * x + 2 * y - 3 * z
target = {x: 1, y: 2, z: -3}
linear_terms_const, quad_terms_const = parse_optimization_expression(
Constraint(expr, lb=0))
linear_terms_obj, quad_terms_obj = parse_optimization_expression(
Objective(expr), linear=False)
self.assertEqual(linear_terms_const, target)
self.assertEqual(linear_terms_obj, target)
self.assertEqual(quad_terms_const, {})
self.assertEqual(quad_terms_obj, {})
def test_parse_quadratic_expression(self):
x, y, z = self.vars[:3]
expr = 2 * x**2 + 3 * x * y - 4 * z**2
target = {frozenset([x]): 2, frozenset([z]): -4, frozenset([x, y]): 3}
linear_terms_const, quad_terms_const = parse_optimization_expression(
Constraint(expr, lb=0), linear=False)
linear_terms_obj, quad_terms_obj = parse_optimization_expression(
Objective(expr), quadratic=True)
self.assertEqual(linear_terms_const, {})
self.assertEqual(linear_terms_obj, {})
self.assertEqual(quad_terms_const, target)
self.assertEqual(quad_terms_obj, target)
def test_parse_linear_expression(self):
x, y, z = self.vars[:3]
offset = 3
expr = 1 * x + 2 * y - 3 * z + offset
target = {x: 1, y: 2, z: -3}
offset_const, linear_terms_const, quad_terms_const = parse_optimization_expression(Constraint(expr, lb=0))
offset_obj, linear_terms_obj, quad_terms_obj = parse_optimization_expression(Objective(expr), linear=False)
self.assertEqual(offset_const, 0)
self.assertEqual(offset_obj, offset)
_compare_term_dicts(self, linear_terms_const, target)
_compare_term_dicts(self, linear_terms_obj, target)
self.assertEqual(quad_terms_const, {})
self.assertEqual(quad_terms_obj, {})
def test_parse_quadratic_expression(self):
x, y, z = self.vars[:3]
offset = 4
expr = 2 * x**2 + 3 * x * y - 4 * z**2 + offset
target = {frozenset([x]): 2, frozenset([z]): -4, frozenset([x, y]): 3}
offset_const, linear_terms_const, quad_terms_const = parse_optimization_expression(Constraint(expr, lb=0), linear=False)
offset_obj, linear_terms_obj, quad_terms_obj = parse_optimization_expression(Objective(expr), quadratic=True)
self.assertEqual(offset_const, 0)
self.assertEqual(offset_obj, offset)
self.assertEqual(linear_terms_const, {})
self.assertEqual(linear_terms_obj, {})
_compare_term_dicts(self, quad_terms_const, target)
_compare_term_dicts(self, quad_terms_obj, target)
self.assertEqual((_quad_terms_to_expression(quad_terms_obj) - (expr - offset)).expand(), 0)
self.assertEqual((_quad_terms_to_expression(quad_terms_const) - (expr - offset)).expand(), 0)
def test_parse_non_expanded_quadratic_expression(self):
x, y, z = self.vars[:3]
expr = (x + y)**2 - (z - 2)**2
target = {
frozenset([x]): 1,
frozenset([y]): 1,
frozenset([x, y]): 2,
frozenset([z]): -1
}
linear_target = {z: 4}
linear_terms_const, quad_terms_const = parse_optimization_expression(
Constraint(expr, lb=0), quadratic=True)
linear_terms_obj, quad_terms_obj = parse_optimization_expression(
Objective(expr), linear=False)
self.assertEqual(linear_terms_const, linear_target)
self.assertEqual(linear_terms_obj, linear_target)
self.assertEqual(quad_terms_const, target)
self.assertEqual(quad_terms_obj, target)
def test_number_objective(self):
self.model.objective = Objective(0.)
self.assertEqual(self.model.objective.__str__(), 'Maximize\n0')
def test_number_objective(self):
self.model.objective = Objective(0.)
self.assertIn('Maximize\n0', self.model.objective.__str__())