You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
140 lines
4.4 KiB
140 lines
4.4 KiB
# MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
|
|
# Copyright (C) 2020-2021, UChicago Argonne, LLC. All rights reserved.
|
|
# Released under the modified BSD license. See COPYING.md for more details.
|
|
|
|
from miplearn.features import (
|
|
FeaturesExtractor,
|
|
InstanceFeatures,
|
|
Variable,
|
|
Constraint,
|
|
)
|
|
from miplearn.solvers.gurobi import GurobiSolver
|
|
from miplearn.solvers.tests import assert_equals, _round_variables, _round_constraints
|
|
|
|
inf = float("inf")
|
|
|
|
|
|
def test_knapsack() -> None:
|
|
solver = GurobiSolver()
|
|
instance = solver.build_test_instance_knapsack()
|
|
model = instance.to_model()
|
|
solver.set_instance(instance, model)
|
|
solver.solve_lp()
|
|
|
|
features = FeaturesExtractor(solver).extract(instance)
|
|
assert features.variables is not None
|
|
assert features.constraints is not None
|
|
assert features.instance is not None
|
|
|
|
assert_equals(
|
|
_round_variables(features.variables),
|
|
{
|
|
"x[0]": Variable(
|
|
basis_status="U",
|
|
category="default",
|
|
lower_bound=0.0,
|
|
obj_coeff=505.0,
|
|
reduced_cost=193.615385,
|
|
sa_lb_down=-inf,
|
|
sa_lb_up=1.0,
|
|
sa_obj_down=311.384615,
|
|
sa_obj_up=inf,
|
|
sa_ub_down=0.913043,
|
|
sa_ub_up=2.043478,
|
|
type="C",
|
|
upper_bound=1.0,
|
|
user_features=[23.0, 505.0],
|
|
value=1.0,
|
|
alvarez_2017=[1.0, 0.32899, 0.0, 0.0, 1.0, 1.0, 5.265874, 46.051702],
|
|
),
|
|
"x[1]": Variable(
|
|
basis_status="B",
|
|
category="default",
|
|
lower_bound=0.0,
|
|
obj_coeff=352.0,
|
|
reduced_cost=0.0,
|
|
sa_lb_down=-inf,
|
|
sa_lb_up=0.923077,
|
|
sa_obj_down=317.777778,
|
|
sa_obj_up=570.869565,
|
|
sa_ub_down=0.923077,
|
|
sa_ub_up=inf,
|
|
type="C",
|
|
upper_bound=1.0,
|
|
user_features=[26.0, 352.0],
|
|
value=0.923077,
|
|
alvarez_2017=[
|
|
1.0,
|
|
0.229316,
|
|
0.0,
|
|
0.076923,
|
|
1.0,
|
|
1.0,
|
|
3.532875,
|
|
5.388476,
|
|
],
|
|
),
|
|
"x[2]": Variable(
|
|
basis_status="U",
|
|
category="default",
|
|
lower_bound=0.0,
|
|
obj_coeff=458.0,
|
|
reduced_cost=187.230769,
|
|
sa_lb_down=-inf,
|
|
sa_lb_up=1.0,
|
|
sa_obj_down=270.769231,
|
|
sa_obj_up=inf,
|
|
sa_ub_down=0.9,
|
|
sa_ub_up=2.2,
|
|
type="C",
|
|
upper_bound=1.0,
|
|
user_features=[20.0, 458.0],
|
|
value=1.0,
|
|
alvarez_2017=[1.0, 0.298371, 0.0, 0.0, 1.0, 1.0, 5.232342, 46.051702],
|
|
),
|
|
"x[3]": Variable(
|
|
basis_status="L",
|
|
category="default",
|
|
lower_bound=0.0,
|
|
obj_coeff=220.0,
|
|
reduced_cost=-23.692308,
|
|
sa_lb_down=-0.111111,
|
|
sa_lb_up=1.0,
|
|
sa_obj_down=-inf,
|
|
sa_obj_up=243.692308,
|
|
sa_ub_down=0.0,
|
|
sa_ub_up=inf,
|
|
type="C",
|
|
upper_bound=1.0,
|
|
user_features=[18.0, 220.0],
|
|
value=0.0,
|
|
alvarez_2017=[1.0, 0.143322, 0.0, 0.0, 1.0, -1.0, 46.051702, 3.16515],
|
|
),
|
|
},
|
|
)
|
|
assert_equals(
|
|
_round_constraints(features.constraints),
|
|
{
|
|
"eq_capacity": Constraint(
|
|
basis_status="N",
|
|
category="eq_capacity",
|
|
dual_value=13.538462,
|
|
lazy=False,
|
|
lhs={"x[0]": 23.0, "x[1]": 26.0, "x[2]": 20.0, "x[3]": 18.0},
|
|
rhs=67.0,
|
|
sa_rhs_down=43.0,
|
|
sa_rhs_up=69.0,
|
|
sense="<",
|
|
slack=0.0,
|
|
user_features=[0.0],
|
|
)
|
|
},
|
|
)
|
|
assert_equals(
|
|
features.instance,
|
|
InstanceFeatures(
|
|
user_features=[67.0, 21.75],
|
|
lazy_constraint_count=0,
|
|
),
|
|
)
|