def test_lp4():
lp = LinearProgram()
x, y, z = lp.Var(), lp.Var(), lp.Var()
lp.objective = 10 * x - 6 * y + 4 * z
lp.add_constraint(0 <= x <= 10)
lp.add_constraint(0 <= y <= 10)
lp.add_constraint(0 <= z <= 10)
minval = lp.minimize()
print(minval)
print(x.value, y.value, z.value)
assert minval == -60
assert (x.value, y.value, z.value) == (0, 10, 0)
def test_lp2():
lp = LinearProgram()
x, y, z = lp.Var(), lp.Var(), lp.Var()
lp.objective = 10 * x - 6 * y + 4 * z
lp.add_constraint(x <= 10)
lp.add_constraint(0 <= y)
lp.add_constraint(z <= 10)
maxval = lp.maximize()
print(maxval)
print(x.value, y.value, z.value)
assert maxval == 140
assert (x.value, y.value, z.value) == (10, 0, 10)
def test_isub():
lp = LinearProgram()
x, y = lp.Var(), lp.Var()
lp.objective += 10 * x - 6 * y
lp.add_constraint(x <= 10)
lp.add_constraint(0 <= y)
lp.objective -= 6 * y
z = lp.Var()
lp.add_constraint(z <= 10)
lp.objective += 4 * z
maxval = lp.maximize()
print(maxval)
print(x.value, y.value, z.value)
assert maxval == 140
assert (x.value, y.value, z.value) == (10, 0, 10)
def test_expr():
lp = LinearProgram()
x, y = lp.Var(), lp.Var()
assert str(x + y) == " 1.00 X1 + 1.00 X2"
assert str(2 * (x + y)) == " 2.00 X1 + 2.00 X2"
assert str(2 * x + 3 * y) == " 2.00 X1 + 3.00 X2"
assert str(0 <= 2 * x) == " 2.00 X1 >= 0.00"
assert str(3 * y <= 7) == " 3.00 X2 <= 7.00"
e = 0 <= 2 * x + 3 * y <= 7
assert str(e) == " 0.00 <= 2.00 X1 + 3.00 X2 <= 7.00"
e = 2 * x + 3 * y
assert str(e <= 7) == " 2.00 X1 + 3.00 X2 <= 7.00"
assert str(0 <= e) == " 2.00 X1 + 3.00 X2 >= 0.00"
assert str(x * 4 == 8) == " 4.00 X1 == 8.00"
assert str(y <= 6) == "X2 <= 6.00"
assert str(2 * x - 3 * y) == " 2.00 X1 + -3.00 X2"
e += 3 * lp.Var()
assert str(e) == " 2.00 X1 + 3.00 X2 + 3.00 X3"
def test_lp3():
lp = LinearProgram()
x, y, z = lp.Var(), lp.Var(), lp.Var()
lp.objective = 10 * x + 6 * y + 4 * z
lp.add_constraint(x + y + z <= 100)
lp.add_constraint(10 * x + 4 * y + 5 * z <= 600)
lp.add_constraint(2 * x + 2 * y + 6 * z <= 300)
lp.add_constraint(x >= 0)
lp.add_constraint(y >= 0)
lp.add_constraint(z >= 0)
maxval = lp.maximize()
print(maxval)
print(x.value, y.value, z.value)
assert int(maxval) == 733
assert int(x.value) == 33
assert int(y.value) == 66
assert int(z.value) == 0