def test__get_pivoting_row(self):
"""Test Tableau._get_pivoting_row method."""
tableau = lp.Tableau(5, 2)
tableau.add_constraint([-6, 0, 1, -2, 2, 6], 2)
tableau.add_constraint([-3, 1, 0, 6, 3, 15], 1)
tableau.add_cost_function([5, 0, 0, 3, -2, -21])
self.assertEqual(tableau._get_pivoting_row(4), 0)
def test__pivote(self):
"""Test Tableau._pivote method."""
tableau = lp.Tableau(3, 3)
tableau.add_constraint([1, 4, 2, 6], 0)
tableau.add_constraint([3, 14, 8, 16], 1)
tableau.add_constraint([4, 21, 10, 28], 2)
# Pivote by x1 in the first equation
tableau._pivote(0, 0)
self.assertEqual(
tableau._tableau,
[[1.0, 4.0, 2.0, 6.0], [0.0, 2.0, 2.0, -2.0], [0.0, 5.0, 2.0, 4.0]
],
)
# Pivote by x2 in the second equation
tableau._pivote(1, 1)
self.assertEqual(
tableau._tableau,
[[1.0, 0.0, -2.0, 10.0], [0.0, 1.0, 1.0, -1.0],
[0.0, 0.0, -3.0, 9.0]],
)
# Pivote by x3 in the third equation
tableau._pivote(2, 2)
self.assertEqual(
tableau._tableau,
[[1.0, 0.0, 0.0, 4.0], [0.0, 1.0, 0.0, 2.0], [0.0, 0.0, 1.0, -3.0]
],
)
def test_is_basic_feasible_solution_fails(self):
"""Test Tableau.is_basic_feasible_solution failures."""
tableau = lp.Tableau(4, 2)
tableau.add_constraint([1, 1, 2, 1, 6], 0)
tableau.add_constraint([0, 3, 1, 8, 3], 1)
tableau.add_cost_function([0, 0, 0, 0, 0])
self.assertRaises(AssertionError, tableau.is_basic_feasible_solution)
def test_is_basic_feasible_solution(self):
"""Test Tableau.is_basic_feasible_solution method."""
tableau = lp.Tableau(4, 2)
tableau.add_constraint([1, 0, 1.667, 1.667, 5], 0)
tableau.add_constraint([0, 1, 0.333, 2.667, 1], 1)
tableau.add_cost_function([0, 0, 0, 0, 0])
self.assertTrue(tableau.is_basic_feasible_solution())
def test_is_canonical_almost_canonical(self):
"""Test Tableau.is_canonical when no canonical."""
tableau = lp.Tableau(2, 2)
tableau.add_constraint([1, 2, 5], 0)
tableau.add_constraint([0, 1, 5], 1)
tableau.add_cost_function([2, 3, 5])
self.assertFalse(tableau.is_canonical())
def test_is_minimum(self):
"""Test Tableau.is_minimum method."""
tableau = lp.Tableau(3, 2)
tableau.add_constraint([1, 2, 3, 4], 0)
tableau.add_constraint([0, 1, 2, 3], 1)
tableau.add_cost_function([0, 0, 1, 2])
self.assertTrue(tableau.is_minimum())
def test_is_canonical(self):
"""Test Tableau.is_canonical when canonical."""
tableau = lp.Tableau(2, 2)
tableau.add_constraint([1, 0, 5], 0)
tableau.add_constraint([0, 1, 5], 1)
tableau.add_cost_function([0, 0, 5])
self.assertTrue(tableau.is_canonical())
def test_cost_function(self):
"""Test Tableau.cost_function for non artificial models."""
tableau = lp.Tableau(3, 2)
tableau.add_constraint([1, 2, 3, 4], 0)
tableau.add_constraint([0, 1, 2, 3], 1)
tableau.add_cost_function([0, 0, 1, 2])
self.assertEqual(tableau.cost_function(), [0, 0, 1, 2])
def test_is_minimum_artificial_not_minimum(self):
"""Test Tableau.is_minimum method."""
tableau = lp.Tableau(3, 2)
tableau.add_constraint([1, 2, 3, 4], 0)
tableau.add_constraint([0, 1, 2, 3], 1)
tableau.add_cost_function([0, 0, 1, 2])
tableau.add_artificial_function([2, -3, 0, 0])
self.assertFalse(tableau.is_minimum())
def test_drop_artificial_artificial_variable(self):
"""Test Tableau.drop_artificial fails when artificial variable."""
tableau = lp.Tableau(4, 2)
tableau.add_constraint([1, 2, 1, 0, 5], 2)
tableau.add_constraint([0, 1, 0, 1, 5], 3)
tableau.add_cost_function([2, 3, 0, 0, 5])
tableau.add_artificial_function([1, 3, 0, 0, -15])
self.assertRaises(AssertionError, tableau.drop_artificial)
def test_drop_artificial_not_minimal(self):
"""Test Tableau.drop_artificial fails when not minimal."""
tableau = lp.Tableau(4, 2)
tableau.add_constraint([1, 2, 1, 0, 5], 0)
tableau.add_constraint([0, 1, 0, 1, 5], 1)
tableau.add_cost_function([2, 3, 0, 0, 5])
tableau.add_artificial_function([-1, -3, 0, 0, -15])
self.assertRaises(AssertionError, tableau.drop_artificial)
def test_constraints(self):
"""Test Tableau.constraints method."""
tableau = lp.Tableau(3, 2)
tableau.add_constraint([1, 2, 3, 4], 0)
tableau.add_constraint([0, 1, 2, 3], 1)
tableau.add_cost_function([0, 0, 1, 2])
tableau.add_artificial_function([1, 3, 5, 7])
self.assertEqual(tableau.constraints(), [[1, 2, 3, 4], [0, 1, 2, 3]])
def test_add_cost_function(self):
"""Test Tableau.add_cost_function success."""
tableau = lp.Tableau(3, 2)
tableau.add_constraint([1, 2, 3, 4], 0)
tableau.add_constraint([0, 1, 2, 3], 1)
tableau.add_cost_function([0, 0, 1, 2])
self.assertEqual(tableau._tableau,
[[1, 2, 3, 4], [0, 1, 2, 3], [0, 0, 1, 2]])
def test_add_constraint_fails(self):
"""Test Tableau.add_constraint asserts."""
tableau = lp.Tableau(3, 2)
self.assertRaises(AssertionError, tableau.add_constraint, [1], 0)
self.assertRaises(AssertionError, tableau.add_constraint,
[1, 2, 3, 4, 5], 0)
tableau.add_constraint([1, 2, 3, 4], 0)
self.assertRaises(AssertionError, tableau.add_constraint, [1, 2, 3, 4],
0)
def test_drop_artificial(self):
"""Test Tableau.drop_artificial method."""
tableau = lp.Tableau(4, 2)
tableau.add_constraint([1, 2, 1, 0, 5], 0)
tableau.add_constraint([0, 1, 0, 1, 5], 1)
tableau.add_cost_function([2, 3, 0, 0, 5])
tableau.add_artificial_function([1, 3, 0, 0, -15])
tableau.drop_artificial()
self.assertFalse(tableau._artificial)
self.assertEqual(tableau._tableau, [[1, 2, 5], [0, 1, 5], [2, 3, 5]])
def test_simplex(self):
"""Test Tableau.simplex method."""
tableau = lp.Tableau(5, 2)
tableau.add_constraint([-6, 0, 1, -2, 2, 6], 2)
tableau.add_constraint([-3, 1, 0, 6, 3, 15], 1)
tableau.add_cost_function([5, 0, 0, 3, -2, -21])
tableau.simplex()
self.assertEqual(tableau._basic_variables, [4, 0])
self.assertEqual(tableau._tableau,
[[0.0, 1 / 2, -1 / 4, 7 / 2, 1.0, 6.0],
[1.0, 1 / 6, -1 / 4, 3 / 2, 0.0, 1.0],
[0.0, 1 / 6, 3 / 4, 5 / 2, 0.0, -14.0]])
def test_add_artificial_function_fails(self):
"""Test Tableau.add_artificial_function asserts."""
tableau = lp.Tableau(3, 2)
self.assertRaises(AssertionError, tableau.add_artificial_function, [1])
self.assertRaises(AssertionError, tableau.add_artificial_function,
[1, 2, 3, 4])
def test_add_constraint(self):
"""Test Tableau.add_constraint success."""
tableau = lp.Tableau(3, 2)
tableau.add_constraint([1, 2, 3, 4], 0)
self.assertEqual(tableau._basic_variables, [0])
self.assertEqual(tableau._tableau, [[1, 2, 3, 4]])
