def testPerformPivot(self):
s = Simplex(testMatrix2)
row, column = s.choosePivot()
self.assertEqual((row, column), (1, 0))
s.performPivot(row, column)
expected = Array([
[F(0), F(7, 2), F(-1, 2), F(5, 2), F(0), F(0), F(25, 2)],
[F(1), F(3, 2), F(1, 2), F(1, 2), F(0), F(0), F(5, 2)],
[F(0), F(-5), F(0), F(-2), F(1), F(0), F(1)],
[F(0), F(-1, 2), F(1, 2), F(-3, 2), F(0), F(1), F(1, 2)],
])
for i in range(len(expected)):
self.assertEqual(s.tableaux[i], expected[i], "(row %d)" % i)
self.assertEqual(s.basicVariables[1:], [0, 4, 5])
row, column = s.choosePivot()
self.assertEqual((row, column), (3, 2))
s.performPivot(row, column)
expected = Array([
[F(0), F(3), F(0), F(1), F(0), F(1), F(13)],
[F(1), F(2), F(0), F(2), F(0), F(-1), F(2)],
[F(0), F(-5), F(0), F(-2), F(1), F(0), F(1)],
[F(0), F(-1), F(1), F(-3), F(0), F(2), F(1)],
])
for i in range(len(expected)):
self.assertEqual(s.tableaux[i], expected[i], "(row %d)" % i)
self.assertEqual(s.basicVariables[1:], [0, 4, 2])
def testChosePivot(self):
s = Simplex(testMatrix2)
row, column = s.choosePivot()
self.assertEqual(column, 0)
self.assertEqual(row, 1)
for i in range(3):
s.tableaux[0][i] = F(1)
with self.assertRaises(EndOfAlgorithm):
row, column = s.choosePivot()
s.tableaux[0][0] = F(-1)
for i in range(1, 4):
s.tableaux[i][0] = F(-1)
with self.assertRaises(Unbounded):
row, column = s.choosePivot()