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