+ def test_solutions_dont_change_orthant(self):
+ G = random_orthant_game()
+ self.assert_solutions_dont_change(G)
+
+ def test_solutions_dont_change_icecream(self):
+ G = random_icecream_game()
+ self.assert_solutions_dont_change(G)
+
+ def assert_solutions_dont_change(self, G):
+ """
+ If we solve the same problem twice, we should get
+ the same answer both times.
+ """
+ soln1 = G.solution()
+ soln2 = G.solution()
+ p1_diff = norm(soln1.player1_optimal() - soln2.player1_optimal())
+ p2_diff = norm(soln1.player2_optimal() - soln2.player2_optimal())
+ gv_diff = abs(soln1.game_value() - soln2.game_value())
+
+ p1_close = p1_diff < options.ABS_TOL
+ p2_close = p2_diff < options.ABS_TOL
+ gv_close = gv_diff < options.ABS_TOL
+
+ self.assertTrue(p1_close and p2_close and gv_close)
+