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.
41 lines
1.3 KiB
41 lines
1.3 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 typing import Any
|
|
|
|
from pyomo import environ as pe
|
|
|
|
from miplearn.instance import Instance
|
|
from miplearn.solvers.gurobi import GurobiSolver
|
|
from miplearn.solvers.pyomo.base import BasePyomoSolver
|
|
from tests.solvers import _is_subclass_or_instance
|
|
|
|
|
|
class InfeasiblePyomoInstance(Instance):
|
|
def to_model(self) -> pe.ConcreteModel:
|
|
model = pe.ConcreteModel()
|
|
model.x = pe.Var([0], domain=pe.Binary)
|
|
model.OBJ = pe.Objective(expr=model.x[0], sense=pe.maximize)
|
|
model.eq = pe.Constraint(expr=model.x[0] >= 2)
|
|
return model
|
|
|
|
|
|
class InfeasibleGurobiInstance(Instance):
|
|
def to_model(self) -> Any:
|
|
import gurobipy as gp
|
|
from gurobipy import GRB
|
|
|
|
model = gp.Model()
|
|
x = model.addVars(1, vtype=GRB.BINARY, name="x")
|
|
model.addConstr(x[0] >= 2)
|
|
model.setObjective(x[0])
|
|
return model
|
|
|
|
|
|
def get_infeasible_instance(solver):
|
|
if _is_subclass_or_instance(solver, BasePyomoSolver):
|
|
return InfeasiblePyomoInstance()
|
|
if _is_subclass_or_instance(solver, GurobiSolver):
|
|
return InfeasibleGurobiInstance()
|