COPT

Using Copt as a solver backend.

from benderslib import AnnotatedBenders, ClassicalBenders
from benderslib.solvers import Copt
from benderslib.utils import draw_curve

import inspect
from pathlib import Path

try:
    from coptpy import COPT
    import coptpy

    copt_available = True
except ImportError:
    copt_available = False


def make_original_problem():
    env = coptpy.Envr()
    model = env.createModel()

    # Get the directory of the current file
    current_file_path = inspect.getfile(inspect.currentframe())
    lp_file_path = Path(current_file_path).parent / "m.lp"
    model.readLp(str(lp_file_path))

    complicating_vars = [v.name for v in model.getVars() if v.vtype != COPT.CONTINUOUS]
    return model, complicating_vars


if __name__ == '__main__':
    if copt_available:
        model, complicating_vars = make_original_problem()
        model_copy = model.clone()
        model.solve()

        BD = AnnotatedBenders(model, solver=Copt, complicating_vars=complicating_vars, benders=ClassicalBenders)
        BD.solve()

        BD = AnnotatedBenders(model_copy, solver=Copt, complicating_vars=complicating_vars, benders=ClassicalBenders)
        BD.params.use_bnc = True
        BD.solve()

        draw_curve(BD.result)

Tags: benders: classical, solver: copt, deterministic, branch-and-check