def testTrivialUnbounded(self):
"""
Maximize x_0 st x_0 >= 4
"""
s = Simplex(Array([
[F(-1), F(0), F(0)],
[F(-1), F(1),F(-4)]
]))
s.variableFromIndex = {i : str(i) for i in range(s.nbVariables)}
with self.assertRaises(Unbounded):
s.solve()
def testSolve2(self):
s = Simplex(Array(testMatrix1))
s.variableFromIndex = {i : str(i) for i in range(s.nbVariables)}
opt, optSol = s.solve()
self.assertEqual(opt, -20)
self.assertEqual(optSol, {
'0' : 0,
'1' : 12,
'2' : 22,
'3' : 0
})
s = Simplex(testMatrix2)
s.variableFromIndex = {i : str(i) for i in range(s.nbVariables)}
opt, optSol = s.solve()
self.assertEqual(opt, 13)
self.assertEqual(optSol, {
'0' : 2,
'1' : 0,
'2' : 1
})
def testTrivialEmpty(self):
"""
Maximize 0 st x_0 <= 3 AND x_0 >= 4
"""
s = Simplex(Array([
[F(0), F(0), F(0), F(0)],
[F(1), F(1), F(0), F(3)],
[F(-1), F(0), F(1), F(-4)]
]))
s.variableFromIndex = {i : str(i) for i in range(s.nbVariables)}
with self.assertRaises(Empty):
s.solve()
def testSolve(self):
s = Simplex(testMatrix1)
s.variableFromIndex = {i : str(i) for i in range(s.nbVariables)}
objective = s.tableaux[0].copy()
s.tableaux[0] = s.tableaux[0].__class__(([0]*len(s.tableaux[0])))
s.addVariable()
expected = Array([
[F(1), F(0), F(0), F(0), F(0), F(0), F(0), F(0)],
[F(-1), F(4), F(-2), F(1), F(-1), F(1), F(0), F(-2)],
[F(-1), F(-1), F(1), F(-1), F(0), F(0), F(1), F(-10)],
])
for i in range(len(expected)):
self.assertEqual(s.tableaux[i], expected[i], "(row %d)" % i)
row, value = s.firstPhaseLeavingVariable()
self.assertEqual(row, 2)
s.performPivot(row, 0)
expected = Array([
[F(0), F(-1), F(1), F(-1), F(0), F(0), F(1), F(-10)],
[F(0), F(5), F(-3), F(2), F(-1), F(1), F(-1), F(8)],
[F(1), F(1), F(-1), F(1), F(0), F(0), F(-1), F(10)],
])
for i in range(len(expected)):
self.assertEqual(s.tableaux[i], expected[i], "(row %d)" % i)
row, column = 1, 3
s.performPivot(row, column)
expected = Array([
[F(0), F(3, 2), F(-1, 2), F(0), F(-1, 2), F(1, 2), F(1, 2), F(-6)],
[F(0), F(5, 2), F(-3, 2), F(1), F(-1, 2), F(1, 2), F(-1, 2), F(4)],
[F(1), F(-3, 2), F(1, 2), F(0), F(1, 2), F(-1, 2), F(-1, 2), F(6)],
])
for i in range(len(expected)):
self.assertEqual(s.tableaux[i], expected[i], "(row %d)" % i)
row, column = 2, 2
s.performPivot(row, column)
expected = Array([
[F(1), F(0), F(0), F(0), F(0), F(0), F(0), F(0)],
[F(3), F(-2), F(0), F(1), F(1), F(-1), F(-2), F(22)],
[F(2), F(-3), F(1), F(0), F(1), F(-1), F(-1), F(12)],
])
for i in range(len(expected)):
self.assertEqual(s.tableaux[i], expected[i], "(row %d)" % i)
s.removeVariable()
s.tableaux[0] = objective
s.updateObjective()
expected = Array([
[F(1), F(0), F(0), F(1), F(0), F(2), F(-20)],
[F(-2), F(0), F(1), F(1), F(-1), F(-2), F(22)],
[F(-3), F(1), F(0), F(1), F(-1), F(-1), F(12)],
])
for i in range(len(expected)):
self.assertEqual(s.tableaux[i], expected[i], "(row %d)" % i)