MIPLearn v0.3

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2023-06-08 11:25:39 -05:00
parent 6cc253a903
commit 1ea989d48a
172 changed files with 10495 additions and 24812 deletions

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# MIPLearn: Extensible Framework for Learning-Enhanced Mixed-Integer Optimization
# Copyright (C) 2020-2021, UChicago Argonne, LLC. All rights reserved.
# Copyright (C) 2020-2022, UChicago Argonne, LLC. All rights reserved.
# Released under the modified BSD license. See COPYING.md for more details.
from tempfile import NamedTemporaryFile
import networkx as nx
import numpy as np
from scipy.stats import uniform, randint
from miplearn.problems.stab import MaxWeightStableSetInstance
from miplearn.solvers.learning import LearningSolver
from miplearn.h5 import H5File
from miplearn.problems.stab import (
MaxWeightStableSetData,
build_stab_model_pyomo,
build_stab_model_gurobipy,
)
def test_stab() -> None:
graph = nx.cycle_graph(5)
weights = np.array([1.0, 1.0, 1.0, 1.0, 1.0])
instance = MaxWeightStableSetInstance(graph, weights)
solver = LearningSolver()
stats = solver._solve(instance)
assert stats["mip_lower_bound"] == 2.0
def test_stab_generator_fixed_graph() -> None:
np.random.seed(42)
from miplearn.problems.stab import MaxWeightStableSetGenerator
gen = MaxWeightStableSetGenerator(
w=uniform(loc=50.0, scale=10.0),
n=randint(low=10, high=11),
p=uniform(loc=0.05, scale=0.0),
fix_graph=True,
data = MaxWeightStableSetData(
graph=nx.cycle_graph(5),
weights=np.array([1.0, 1.0, 1.0, 1.0, 1.0]),
)
data = gen.generate(1_000)
weights = np.array([d.weights for d in data])
weights_avg_actual = np.round(np.average(weights, axis=0))
weights_avg_expected = [55.0] * 10
assert list(weights_avg_actual) == weights_avg_expected
def test_stab_generator_random_graph() -> None:
np.random.seed(42)
from miplearn.problems.stab import MaxWeightStableSetGenerator
gen = MaxWeightStableSetGenerator(
w=uniform(loc=50.0, scale=10.0),
n=randint(low=30, high=41),
p=uniform(loc=0.5, scale=0.0),
fix_graph=False,
)
data = gen.generate(1_000)
n_nodes = [d.graph.number_of_nodes() for d in data]
n_edges = [d.graph.number_of_edges() for d in data]
assert np.round(np.mean(n_nodes)) == 35.0
assert np.round(np.mean(n_edges), -1) == 300.0
for model in [
build_stab_model_pyomo(data),
build_stab_model_gurobipy(data),
]:
with NamedTemporaryFile() as tempfile:
with H5File(tempfile.name) as h5:
model.optimize()
model.extract_after_mip(h5)
assert h5.get_scalar("mip_obj_value") == -2.0