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ortools-clone/ortools/linear_solver/python/model_builder_test.py
2023-03-03 12:12:37 +04:00

559 lines
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Python

#!/usr/bin/env python3
# Copyright 2010-2022 Google LLC
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Tests for ModelBuilder."""
import math
import numpy as np
import numpy.testing as np_testing
import os
from ortools.linear_solver.python import model_builder as mb
import unittest
class ModelBuilderTest(unittest.TestCase):
# Number of decimal places to use for numerical tolerance for
# checking primal, dual, objective values and other values.
NUM_PLACES = 5
# pylint: disable=too-many-statements
def run_minimal_linear_example(self, solver_name):
"""Minimal Linear Example."""
model = mb.ModelBuilder()
model.name = 'minimal_linear_example'
x1 = model.new_num_var(0.0, math.inf, 'x1')
x2 = model.new_num_var(0.0, math.inf, 'x2')
x3 = model.new_num_var(0.0, math.inf, 'x3')
self.assertEqual(3, model.num_variables)
self.assertFalse(x1.is_integral)
self.assertEqual(0.0, x1.lower_bound)
self.assertEqual(math.inf, x2.upper_bound)
x1.lower_bound = 1.0
self.assertEqual(1.0, x1.lower_bound)
model.maximize(10.0 * x1 + 6 * x2 + 4.0 * x3 - 3.5)
self.assertEqual(4.0, x3.objective_coefficient)
self.assertEqual(-3.5, model.objective_offset)
model.objective_offset = -5.5
self.assertEqual(-5.5, model.objective_offset)
c0 = model.add(x1 + x2 + x3 <= 100.0)
self.assertEqual(100, c0.upper_bound)
c1 = model.add(10 * x1 + 4.0 * x2 + 5.0 * x3 <= 600.0, 'c1')
self.assertEqual('c1', c1.name)
c2 = model.add(2.0 * x1 + 2.0 * x2 + 6.0 * x3 <= 300.0)
self.assertEqual(-math.inf, c2.lower_bound)
solver = mb.ModelSolver(solver_name)
self.assertEqual(mb.SolveStatus.OPTIMAL, solver.solve(model))
# The problem has an optimal solution.
self.assertAlmostEqual(733.333333 + model.objective_offset,
solver.objective_value,
places=self.NUM_PLACES)
self.assertAlmostEqual(
solver.value(10.0 * x1 + 6 * x2 + 4.0 * x3 - 5.5),
solver.objective_value,
places=self.NUM_PLACES,
)
self.assertAlmostEqual(33.333333,
solver.value(x1),
places=self.NUM_PLACES)
self.assertAlmostEqual(66.666667,
solver.value(x2),
places=self.NUM_PLACES)
self.assertAlmostEqual(0.0, solver.value(x3), places=self.NUM_PLACES)
dual_objective_value = (solver.dual_value(c0) * c0.upper_bound +
solver.dual_value(c1) * c1.upper_bound +
solver.dual_value(c2) * c2.upper_bound +
model.objective_offset)
self.assertAlmostEqual(solver.objective_value,
dual_objective_value,
places=self.NUM_PLACES)
# x1 and x2 are basic
self.assertAlmostEqual(0.0,
solver.reduced_cost(x1),
places=self.NUM_PLACES)
self.assertAlmostEqual(0.0,
solver.reduced_cost(x2),
places=self.NUM_PLACES)
# x3 is non-basic
x3_expected_reduced_cost = (4.0 - 1.0 * solver.dual_value(c0) -
5.0 * solver.dual_value(c1))
self.assertAlmostEqual(x3_expected_reduced_cost,
solver.reduced_cost(x3),
places=self.NUM_PLACES)
self.assertAlmostEqual(100.0,
solver.activity(c0),
places=self.NUM_PLACES)
self.assertAlmostEqual(600.0,
solver.activity(c1),
places=self.NUM_PLACES)
self.assertAlmostEqual(200.0,
solver.activity(c2),
places=self.NUM_PLACES)
self.assertIn('minimal_linear_example',
model.export_to_lp_string(False))
self.assertIn('minimal_linear_example',
model.export_to_mps_string(False))
def test_minimal_linear_example(self):
self.run_minimal_linear_example('glop')
def test_import_from_mps_string(self):
mps_data = """
* Generated by MPModelProtoExporter
* Name : SupportedMaximizationProblem
* Format : Free
* Constraints : 0
* Variables : 1
* Binary : 0
* Integer : 0
* Continuous : 1
NAME SupportedMaximizationProblem
OBJSENSE
MAX
ROWS
N COST
COLUMNS
X_ONE COST 1
BOUNDS
UP BOUND X_ONE 4
ENDATA
"""
model = mb.ModelBuilder()
self.assertTrue(model.import_from_mps_string(mps_data))
self.assertEqual(model.name, 'SupportedMaximizationProblem')
def test_import_from_mps_file(self):
path = os.path.dirname(__file__)
mps_path = f'{path}/../testdata/maximization.mps'
model = mb.ModelBuilder()
self.assertTrue(model.import_from_mps_file(mps_path))
self.assertEqual(model.name, 'SupportedMaximizationProblem')
def test_import_from_lp_string(self):
lp_data = """
min: x + y;
bin: b1, b2, b3;
1 <= x <= 42;
constraint_num1: 5 b1 + 3b2 + x <= 7;
4 y + b2 - 3 b3 <= 2;
constraint_num2: -4 b1 + b2 - 3 z <= -2;
"""
model = mb.ModelBuilder()
self.assertTrue(model.import_from_lp_string(lp_data))
self.assertEqual(6, model.num_variables)
self.assertEqual(3, model.num_constraints)
self.assertEqual(1, model.var_from_index(0).lower_bound)
self.assertEqual(42, model.var_from_index(0).upper_bound)
self.assertEqual('x', model.var_from_index(0).name)
def test_import_from_lp_file(self):
path = os.path.dirname(__file__)
lp_path = f'{path}/../testdata/small_model.lp'
model = mb.ModelBuilder()
self.assertTrue(model.import_from_lp_file(lp_path))
self.assertEqual(6, model.num_variables)
self.assertEqual(3, model.num_constraints)
self.assertEqual(1, model.var_from_index(0).lower_bound)
self.assertEqual(42, model.var_from_index(0).upper_bound)
self.assertEqual('x', model.var_from_index(0).name)
def test_class_api(self):
model = mb.ModelBuilder()
x = model.new_int_var(0, 10, 'x')
y = model.new_int_var(1, 10, 'y')
z = model.new_int_var(2, 10, 'z')
t = model.new_int_var(3, 10, 't')
e1 = mb.LinearExpr.sum([x, y, z])
expected_vars = np.array([0, 1, 2], dtype=np.int32)
np_testing.assert_array_equal(expected_vars, e1.variable_indices)
np_testing.assert_array_equal(np.array([1, 1, 1], dtype=np.double),
e1.coefficients)
self.assertEqual(e1.constant, 0.0)
self.assertEqual(e1.pretty_string(model.helper), 'x + y + z')
e2 = mb.LinearExpr.sum([e1, 4.0])
np_testing.assert_array_equal(expected_vars, e2.variable_indices)
np_testing.assert_array_equal(np.array([1, 1, 1], dtype=np.double),
e2.coefficients)
self.assertEqual(e2.constant, 4.0)
self.assertEqual(e2.pretty_string(model.helper), 'x + y + z + 4.0')
e3 = mb.LinearExpr.term(e2, 2)
np_testing.assert_array_equal(expected_vars, e3.variable_indices)
np_testing.assert_array_equal(np.array([2, 2, 2], dtype=np.double),
e3.coefficients)
self.assertEqual(e3.constant, 8.0)
self.assertEqual(e3.pretty_string(model.helper),
'2.0 * x + 2.0 * y + 2.0 * z + 8.0')
e4 = mb.LinearExpr.weighted_sum([x, t], [-1, 1], constant=2)
np_testing.assert_array_equal(np.array([0, 3], dtype=np.int32),
e4.variable_indices)
np_testing.assert_array_equal(np.array([-1, 1], dtype=np.double),
e4.coefficients)
self.assertEqual(e4.constant, 2.0)
self.assertEqual(e4.pretty_string(model.helper), '-x + t + 2.0')
e4b = e4 * 3.0
np_testing.assert_array_equal(np.array([0, 3], dtype=np.int32),
e4b.variable_indices)
np_testing.assert_array_equal(np.array([-3, 3], dtype=np.double),
e4b.coefficients)
self.assertEqual(e4b.constant, 6.0)
self.assertEqual(e4b.pretty_string(model.helper),
'-3.0 * x + 3.0 * t + 6.0')
e5 = mb.LinearExpr.sum([e1, -3, e4])
np_testing.assert_array_equal(np.array([0, 1, 2, 0, 3], dtype=np.int32),
e5.variable_indices)
np_testing.assert_array_equal(
np.array([1, 1, 1, -1, 1], dtype=np.double), e5.coefficients)
self.assertEqual(e5.constant, -1.0)
self.assertEqual(e5.pretty_string(model.helper),
'x + y + z - x + t - 1.0')
e6 = mb.LinearExpr.term(x, 2.0, constant=1.0)
np_testing.assert_array_equal(np.array([0], dtype=np.int32),
e6.variable_indices)
np_testing.assert_array_equal(np.array([2], dtype=np.double),
e6.coefficients)
self.assertEqual(e6.constant, 1.0)
e7 = mb.LinearExpr.term(x, 1.0, constant=0.0)
self.assertEqual(x, e7)
e8 = mb.LinearExpr.term(2, 3, constant=4)
self.assertEqual(e8, 10)
def test_variables(self):
model = mb.ModelBuilder()
x = model.new_int_var(0.0, 4.0, 'x')
self.assertEqual(0, x.index)
self.assertEqual(0.0, x.lower_bound)
self.assertEqual(4.0, x.upper_bound)
self.assertEqual('x', x.name)
x.lower_bound = 1.0
x.upper_bound = 3.0
self.assertEqual(1.0, x.lower_bound)
self.assertEqual(3.0, x.upper_bound)
self.assertTrue(x.is_integral)
# Tests the equality operator.
y = model.new_int_var(0.0, 4.0, 'y')
x_copy = model.var_from_index(0)
self.assertEqual(x, x)
self.assertEqual(x, x_copy)
self.assertNotEqual(x, y)
# array
xs = model.new_int_var_array(shape=10,
lower_bounds=0.0,
upper_bounds=5.0,
name='xs_')
self.assertEqual(10, xs.size)
self.assertEqual('xs_4', str(xs[4]))
lbs = np.array([1.0, 2.0, 3.0])
ubs = [3.0, 4.0, 5.0]
ys = model.new_int_var_array(lower_bounds=lbs,
upper_bounds=ubs,
name='ys_')
self.assertEqual('VariableContainer([12 13 14])', str(ys))
zs = model.new_int_var_array(lower_bounds=[1.0, 2.0, 3],
upper_bounds=[4, 4, 4],
name='zs_')
self.assertEqual(3, zs.size)
self.assertEqual((3,), zs.shape)
self.assertEqual('zs_1', str(zs[1]))
self.assertEqual('zs_2(index=17, lb=3.0, ub=4.0, integer)', repr(zs[2]))
self.assertTrue(zs[2].is_integral)
bs = model.new_bool_var_array([4, 5], 'bs_')
self.assertEqual((4, 5), bs.shape)
self.assertEqual((5, 4), bs.T.shape)
self.assertEqual(31, bs.index_at((2, 3)))
self.assertEqual(20, bs.size)
self.assertEqual((20,), bs.flatten().shape)
self.assertTrue(bs[1, 1].is_integral)
# Slices are [lb, ub) closed - open.
self.assertEqual(5, bs[3, :].size)
self.assertEqual(6, bs[1:3, 2:5].size)
sum_bs = np.sum(bs)
self.assertEqual(20, sum_bs.variable_indices.size)
np_testing.assert_array_equal(sum_bs.variable_indices,
bs.variable_indices.flatten())
np_testing.assert_array_equal(sum_bs.coefficients, np.ones(20))
sum_bs_cte = np.sum(bs, 2.2)
self.assertEqual(20, sum_bs_cte.variable_indices.size)
np_testing.assert_array_equal(sum_bs_cte.variable_indices,
bs.variable_indices.flatten())
np_testing.assert_array_equal(sum_bs.coefficients, np.ones(20))
self.assertEqual(sum_bs_cte.constant, 2.2)
times_bs = np.dot(bs[1], 4)
np_testing.assert_array_equal(times_bs.variable_indices,
bs[1].variable_indices.flatten())
np_testing.assert_array_equal(times_bs.coefficients, np.full(5, 4.0))
times_bs_rev = np.dot(4, bs[2])
np_testing.assert_array_equal(times_bs_rev.variable_indices,
bs[2].variable_indices.flatten())
np_testing.assert_array_equal(times_bs_rev.coefficients,
np.full(5, 4.0))
dot_bs = np.dot(bs[2], np.array([1, 2, 3, 4, 5], dtype=np.double))
np_testing.assert_array_equal(dot_bs.variable_indices,
bs[2].variable_indices)
np_testing.assert_array_equal(dot_bs.coefficients, [1, 2, 3, 4, 5])
# Tests the hash method.
var_set = set()
var_set.add(x)
self.assertIn(x, var_set)
self.assertIn(x_copy, var_set)
self.assertNotIn(y, var_set)
def test_numpy_var_arrays(self):
model = mb.ModelBuilder()
x = model.new_var_array(
lower_bounds=0.0,
upper_bounds=4.0,
shape=[2, 3],
is_integral=False,
)
np_testing.assert_array_equal(x.shape, [2, 3])
y = model.new_var_array(
lower_bounds=[[0.0, 1.0, 2.0], [0.0, 0.0, 2.0]],
upper_bounds=4.0,
is_integral=False,
name='y',
)
np_testing.assert_array_equal(y.shape, [2, 3])
z = model.new_var_array(
lower_bounds=0.0,
upper_bounds=[[2.0, 1.0, 2.0], [3.0, 4.0, 2.0]],
is_integral=False,
name='z',
)
np_testing.assert_array_equal(z.shape, [2, 3])
with self.assertRaises(ValueError):
x = model.new_var_array(
lower_bounds=0.0,
upper_bounds=4.0,
is_integral=False,
)
with self.assertRaises(ValueError):
x = model.new_var_array(
lower_bounds=[0, 0],
upper_bounds=[1, 2, 3],
is_integral=False,
)
with self.assertRaises(ValueError):
x = model.new_var_array(
shape=[2, 3],
lower_bounds=0.0,
upper_bounds=[1, 2, 3],
is_integral=False,
)
with self.assertRaises(ValueError):
x = model.new_var_array(
shape=[2, 3],
lower_bounds=[1, 2],
upper_bounds=4.0,
is_integral=False,
)
with self.assertRaises(ValueError):
x = model.new_var_array(
shape=[2, 3],
lower_bounds=0.0,
upper_bounds=4.0,
is_integral=[False, True],
)
with self.assertRaises(ValueError):
x = model.new_var_array(
lower_bounds=[1, 2],
upper_bounds=4.0,
is_integral=[False, False, False],
)
def test_numpy_num_var_arrays(self):
model = mb.ModelBuilder()
x = model.new_num_var_array(
lower_bounds=0.0,
upper_bounds=4.0,
shape=[2, 3],
)
np_testing.assert_array_equal(x.shape, [2, 3])
y = model.new_num_var_array(
lower_bounds=[[0.0, 1.0, 2.0], [0.0, 0.0, 2.0]],
upper_bounds=4.0,
name='y',
)
np_testing.assert_array_equal(y.shape, [2, 3])
z = model.new_num_var_array(
lower_bounds=0.0,
upper_bounds=[[2.0, 1.0, 2.0], [3.0, 4.0, 2.0]],
name='z',
)
np_testing.assert_array_equal(z.shape, [2, 3])
with self.assertRaises(ValueError):
x = model.new_num_var_array(
lower_bounds=0.0,
upper_bounds=4.0,
)
with self.assertRaises(ValueError):
x = model.new_num_var_array(
lower_bounds=[0, 0],
upper_bounds=[1, 2, 3],
)
with self.assertRaises(ValueError):
x = model.new_num_var_array(
shape=[2, 3],
lower_bounds=0.0,
upper_bounds=[1, 2, 3],
)
with self.assertRaises(ValueError):
x = model.new_num_var_array(
shape=[2, 3],
lower_bounds=[1, 2],
upper_bounds=4.0,
)
def test_numpy_int_var_arrays(self):
model = mb.ModelBuilder()
x = model.new_int_var_array(
lower_bounds=0.0,
upper_bounds=4.0,
shape=[2, 3],
)
np_testing.assert_array_equal(x.shape, [2, 3])
y = model.new_int_var_array(
lower_bounds=[[0.0, 1.0, 2.0], [0.0, 0.0, 2.0]],
upper_bounds=4.0,
name='y',
)
np_testing.assert_array_equal(y.shape, [2, 3])
z = model.new_int_var_array(
lower_bounds=0.0,
upper_bounds=[[2.0, 1.0, 2.0], [3.0, 4.0, 2.0]],
name='z',
)
np_testing.assert_array_equal(z.shape, [2, 3])
with self.assertRaises(ValueError):
x = model.new_int_var_array(
lower_bounds=0.0,
upper_bounds=4.0,
)
with self.assertRaises(ValueError):
x = model.new_int_var_array(
lower_bounds=[0, 0],
upper_bounds=[1, 2, 3],
)
with self.assertRaises(ValueError):
x = model.new_int_var_array(
shape=[2, 3],
lower_bounds=0.0,
upper_bounds=[1, 2, 3],
)
with self.assertRaises(ValueError):
x = model.new_int_var_array(
shape=[2, 3],
lower_bounds=[1, 2],
upper_bounds=4.0,
)
def test_duplicate_variables(self):
model = mb.ModelBuilder()
x = model.new_int_var(0.0, 4.0, 'x')
y = model.new_int_var(0.0, 4.0, 'y')
z = model.new_int_var(0.0, 4.0, 'z')
model.add(x + 2 * y == x - z)
model.minimize(x + y + z)
solver = mb.ModelSolver('scip')
self.assertEqual(mb.SolveStatus.OPTIMAL, solver.solve(model))
def test_issue_3614(self):
total_number_of_choices = 5 + 1
total_unique_products = 3
standalone_features = list(range(5))
feature_bundle_incidence_matrix = {}
for idx in range(len(standalone_features)):
feature_bundle_incidence_matrix[idx, 0] = 0
feature_bundle_incidence_matrix[0, 0] = 1
feature_bundle_incidence_matrix[1, 0] = 1
bundle_start_idx = len(standalone_features)
# Model
model = mb.ModelBuilder()
y = {}
v = {}
for i in range(total_number_of_choices):
y[i] = model.new_bool_var(f'y_{i}')
for j in range(total_unique_products):
for i in range(len(standalone_features)):
v[i, j] = model.new_bool_var(f'v_{(i,j)}')
model.add(v[i, j] == (y[i] +
(feature_bundle_incidence_matrix[(i, 0)] *
y[bundle_start_idx])))
solver = mb.ModelSolver('scip')
status = solver.solve(model)
self.assertEqual(mb.SolveStatus.OPTIMAL, status)
def test_varcompvar(self):
model = mb.ModelBuilder()
x = model.new_int_var(0.0, 4.0, 'x')
y = model.new_int_var(0.0, 4.0, 'y')
ct = x == y
self.assertEqual(ct.left.index, x.index)
self.assertEqual(ct.right.index, y.index)
if __name__ == '__main__':
unittest.main()