# MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization # Copyright (C) 2020, UChicago Argonne, LLC. All rights reserved. # Released under the modified BSD license. See COPYING.md for more details. import sys import logging from io import StringIO from pyomo import environ as pe from scipy.stats import randint from .base import BasePyomoSolver from .. import RedirectOutput logger = logging.getLogger(__name__) class XpressPyomoSolver(BasePyomoSolver): """ An InternalSolver that uses XPRESS and the Pyomo modeling language. Parameters ---------- params: dict Dictionary of options to pass to the Pyomo solver. For example, {"Threads": 4} to set the number of threads. """ def __init__(self, params=None): super().__init__( solver_factory=pe.SolverFactory("xpress_persistent"), params={ "randomseed": randint(low=0, high=1000).rvs(), }, )