def test_add_constraint(self):
A = np.array([
[-1, 1],
[1, 1]
])
b = np.array([0, 2])
c = np.array([1, 1.5])
const = 0
mode = "max"
s1 = Simplex(A, b, c, const, mode)
s1.solve()
A2 = np.array([
[-1, 1],
[1, 1],
[0, 1]
])
b2 = np.array([0, 2, 0.5])
c2 = np.array([1, 1.5])
const2 = 0
mode2 = "max"
s2 = Simplex(A2, b2, c2, const2, mode2)
s2.solve()
s1.add_constraint(np.array([0, 1]), 0.5)
s1.reset()
s1.solve()
self.assertTrue(np.allclose(s1.A, s2.A))
self.assertTrue(np.allclose(s1.b, s2.b))
self.assertTrue(np.allclose(s1.c, s2.c))
self.assertTrue(np.allclose(s1.sol(), s2.sol()))
self.assertTrue(np.allclose(s1.obj_val(), s2.obj_val()))
def testPivot():
solver = Simplex([0.0, 0.0, 0.0, 1.0, 2.0, 1.0, 1.0])
solver.add_constraint([1, 0, 0, 1, 1, -1], 5)
solver.add_constraint([0, 1, 0, 2, -3, 1], 3)
solver.add_constraint([0, 0, 1, -1, 2, -1], -1)
solver.set_index([1, 2, 3])
print(solver.table)
solver.pivot(1, 4)
print(solver.table)
def testLPSolver():
solver = Simplex([0, 0, 0, -12, 0, -284])
solver.add_constraint([0, -1, 1, -1, 0], 16)
solver.add_constraint([1, 2, 0, 1, 0], 12)
solver.add_constraint([0, 3, 0, 1, 1], 17)
solver.print_info()
solver.set_index([3, 1, 5])
solver.pivot(5, 2)
solver.print_info()
def get_relaxation_solution(goal_expr, linear_equations, var_num):
s = Simplex(goal_expr['mat'], max_mode=goal_expr['max_mode'])
for eq in linear_equations:
s.add_constraint(eq['mat'], eq['val'])
res = s.solve()
if res is None:
return
expr_val = res[0]
for i in range(1, var_num + 1):
if res[1].get(i) is None:
res[1][i] = 0
return dict(expr_val=expr_val, var_vals=res[1])
def testDegnerateSolver():
solver = Simplex([0.0, 0.0, 0.0, 3 / 4, -20.0, 1 / 2, -6.0, 0.0])
solver.add_constraint([1, 0, 0, 1 / 4, -8, -1, 9], 0)
solver.add_constraint([0, 1, 0, 1 / 2, -12, -1 / 2, 3], 0)
solver.add_constraint([0, 0, 1, 0, 0, 1, 0], 1)
solver.set_index([1, 2, 3])
solver.solveStandard(10)
solver.solveBlandRule(10)
solver.print_info()
from simplex import Simplex
if __name__ == "__main__":
print("Solve the first solution.\n")
t = Simplex('min', [-3, -1, -3])
t.add_constraint([2, 1, 1], 2, "<=")
t.add_constraint([1, 1, 3], 5, "<=")
t.add_constraint([2, 2, 1], 6, "<=")
t.solve()
print("\n\n\nSolve the second solution.\n")
t = Simplex("min", [-9, 12, 41])
t.add_constraint([1, -1, -5], 17, "<=")
t.add_constraint([1, -2, -8], -36, "<=")
t.add_constraint([1, -2, -5], 28, "<=")
t.solve()
