# what happened.
soln_dict = solvers.conelp(c, G, h, C.cvxopt_dims(), A, b)
+ p1_value = -soln_dict['primal objective']
+ p2_value = -soln_dict['dual objective']
+ p1_optimal = soln_dict['x'][1:]
+ p2_optimal = soln_dict['z'][self._K.dimension():]
+
# The "status" field contains "optimal" if everything went
# according to plan. Other possible values are "primal
- # infeasible", "dual infeasible", "unknown", all of which
- # mean we didn't get a solution. That should never happen,
- # because by construction our game has a solution, and thus
- # the cone program should too.
- if soln_dict['status'] != 'optimal':
+ # infeasible", "dual infeasible", "unknown", all of which mean
+ # we didn't get a solution. The "infeasible" ones are the
+ # worst, since they indicate that CVXOPT is convinced the
+ # problem is infeasible (and that cannot happen).
+ if soln_dict['status'] in ['primal infeasible', 'dual infeasible']:
raise GameUnsolvableException(soln_dict)
-
- p1_value = soln_dict['x'][0]
- p1_optimal = soln_dict['x'][1:]
- p2_optimal = soln_dict['z'][self._K.dimension():]
+ elif soln_dict['status'] == 'unknown':
+ # When we get a status of "unknown", we may still be able
+ # to salvage a solution out of the returned
+ # dictionary. Often this is the result of numerical
+ # difficulty and we can simply check that the primal/dual
+ # objectives match (within a tolerance) and that the
+ # primal/dual optimal solutions are within the cone (to a
+ # tolerance as well).
+ if (abs(p1_value - p2_value) > options.ABS_TOL):
+ raise GameUnsolvableException(soln_dict)
+ if (p1_optimal not in self._K) or (p2_optimal not in self._K):
+ raise GameUnsolvableException(soln_dict)
return Solution(p1_value, p1_optimal, p2_optimal)
+
def dual(self):
r"""
Return the dual game to this game.
Tests for the SymmetricLinearGame and Solution classes.
"""
+ def random_orthant_params(self):
+ """
+ Generate the ``L``, ``K``, ``e1``, and ``e2`` parameters for a
+ random game over the nonnegative orthant.
+ """
+ ambient_dim = randint(1, 10)
+ K = NonnegativeOrthant(ambient_dim)
+ e1 = [uniform(0.1, 10) for idx in range(K.dimension())]
+ e2 = [uniform(0.1, 10) for idx in range(K.dimension())]
+ L = [[uniform(-10, 10) for i in range(K.dimension())]
+ for j in range(K.dimension())]
+ return (L, K, e1, e2)
+
+
+ def random_icecream_params(self):
+ """
+ Generate the ``L``, ``K``, ``e1``, and ``e2`` parameters for a
+ random game over the ice cream cone.
+ """
+ # Use a minimum dimension of two to avoid divide-by-zero in
+ # the fudge factor we make up later.
+ ambient_dim = randint(2, 10)
+ K = IceCream(ambient_dim)
+ e1 = [1] # Set the "height" of e1 to one
+ e2 = [1] # And the same for e2
+
+ # If we choose the rest of the components of e1,e2 randomly
+ # between 0 and 1, then the largest the squared norm of the
+ # non-height part of e1,e2 could be is the 1*(dim(K) - 1). We
+ # need to make it less than one (the height of the cone) so
+ # that the whole thing is in the cone. The norm of the
+ # non-height part is sqrt(dim(K) - 1), and we can divide by
+ # twice that.
+ fudge_factor = 1.0 / (2.0*sqrt(K.dimension() - 1.0))
+ e1 += [fudge_factor*uniform(0, 1) for idx in range(K.dimension() - 1)]
+ e2 += [fudge_factor*uniform(0, 1) for idx in range(K.dimension() - 1)]
+ L = [[uniform(-10, 10) for i in range(K.dimension())]
+ for j in range(K.dimension())]
+
+ return (L, K, e1, e2)
+
+
def assert_within_tol(self, first, second):
"""
Test that ``first`` and ``second`` are equal within our default
optimal solutions should give us the optimal game value when we
apply the payoff operator to them.
"""
- ambient_dim = randint(1, 10)
- K = NonnegativeOrthant(ambient_dim)
- e1 = [uniform(0.1, 10) for idx in range(K.dimension())]
- e2 = [uniform(0.1, 10) for idx in range(K.dimension())]
- L = [[uniform(-10, 10) for i in range(K.dimension())]
- for j in range(K.dimension())]
+ (L, K, e1, e2) = self.random_orthant_params()
self.assert_solution_exists(L, K, e1, e2)
def test_solution_exists_ice_cream(self):
Like :meth:`test_solution_exists_nonnegative_orthant`, except
over the ice cream cone.
"""
- # Use a minimum dimension of two to avoid divide-by-zero in
- # the fudge factor we make up later.
- ambient_dim = randint(2, 10)
- K = IceCream(ambient_dim)
- e1 = [1] # Set the "height" of e1 to one
- e2 = [1] # And the same for e2
-
- # If we choose the rest of the components of e1,e2 randomly
- # between 0 and 1, then the largest the squared norm of the
- # non-height part of e1,e2 could be is the 1*(dim(K) - 1). We
- # need to make it less than one (the height of the cone) so
- # that the whole thing is in the cone. The norm of the
- # non-height part is sqrt(dim(K) - 1), and we can divide by
- # twice that.
- fudge_factor = 1.0 / (2.0*sqrt(K.dimension() - 1.0))
- e1 += [fudge_factor*uniform(0, 1) for idx in range(K.dimension() - 1)]
- e2 += [fudge_factor*uniform(0, 1) for idx in range(K.dimension() - 1)]
- L = [[uniform(-10, 10) for i in range(K.dimension())]
- for j in range(K.dimension())]
+ (L, K, e1, e2) = self.random_icecream_params()
self.assert_solution_exists(L, K, e1, e2)
of the game by the same number. Use the nonnegative orthant as
our cone.
"""
- ambient_dim = randint(1, 10)
- K = NonnegativeOrthant(ambient_dim)
- e1 = [uniform(0.1, 10) for idx in range(K.dimension())]
- e2 = [uniform(0.1, 10) for idx in range(K.dimension())]
- L = matrix([[uniform(-10, 10) for i in range(K.dimension())]
- for j in range(K.dimension())])
+ (L, K, e1, e2) = self.random_orthant_params()
+ L = matrix(L) # So that we can scale it by alpha below.
G1 = SymmetricLinearGame(L, K, e1, e2)
value1 = G1.solution().game_value()
alpha = uniform(0.1, 10)
The same test as :meth:`test_nonnegative_scaling_orthant`,
except over the ice cream cone.
"""
- # Use a minimum dimension of two to avoid divide-by-zero in
- # the fudge factor we make up later.
- ambient_dim = randint(2, 10)
- K = IceCream(ambient_dim)
- e1 = [1] # Set the "height" of e1 to one
- e2 = [1] # And the same for e2
-
- # If we choose the rest of the components of e1,e2 randomly
- # between 0 and 1, then the largest the squared norm of the
- # non-height part of e1,e2 could be is the 1*(dim(K) - 1). We
- # need to make it less than one (the height of the cone) so
- # that the whole thing is in the cone. The norm of the
- # non-height part is sqrt(dim(K) - 1), and we can divide by
- # twice that.
- fudge_factor = 1.0 / (2.0*sqrt(K.dimension() - 1.0))
- e1 += [fudge_factor*uniform(0, 1) for idx in range(K.dimension() - 1)]
- e2 += [fudge_factor*uniform(0, 1) for idx in range(K.dimension() - 1)]
- L = matrix([[uniform(-10, 10) for i in range(K.dimension())]
- for j in range(K.dimension())])
+ (L, K, e1, e2) = self.random_icecream_params()
+ L = matrix(L) # So that we can scale it by alpha below.
G1 = SymmetricLinearGame(L, K, e1, e2)
value1 = G1.solution().game_value()
projects / dunshire.git / blobdiff