def test_qp_maximization_reduction_path_qp_solver(self):
qp_maximization = Problem(Maximize(QuadForm(self.x, -self.Q)),
[self.x <= -1])
path = PathFinder().reduction_path(ProblemType(qp_maximization),
[QpSolver])
self.assertEquals(3, len(path))
self.assertEquals(path[1], QpMatrixStuffing)
self.assertEquals(path[2], FlipObjective)
def test_qp_maximization_reduction_path_ecos(self):
qp_maximization = Problem(Maximize(-sum_squares(self.x)),
[self.x <= -1])
self.assertTrue(qp_maximization.is_dcp())
path = PathFinder().reduction_path(ProblemType(qp_maximization),
[ECOS])
self.assertEquals(4, len(path))
self.assertEquals(path[1], ConeMatrixStuffing)
self.assertEquals(path[2], Dcp2Cone)
self.assertEquals(path[3], FlipObjective)
def reduction_path(self, current_type, current_path):
"""A reduction path is like a stack: the first element (0) is the end of the reduction
path (e.g. solver), the first reduction to apply to the problem is path.pop().
"""
if self.is_valid_reduction_path(current_type, current_path):
return current_path
for reduction in self.applicable_reductions(current_type):
self.reductions.remove(reduction)
current_path.insert(1, reduction)
old_type = current_type
if not hasattr(reduction, 'postconditions'):
current_path.pop(1)
current_type = old_type
continue
current_type = ProblemType(reduction.postconditions(current_type))
candidate_path = self.reduction_path(current_type, current_path)
if candidate_path:
return candidate_path
else:
self.reductions.add(reduction)
current_path.pop(1)
current_type = old_type
def test_cone_reduction_path_valid_as_is(self):
path = PathFinder().reduction_path(ProblemType(self.cp), [ECOS])
self.assertEquals(1, len(path))
def test_qp_reduction_path(self):
path = PathFinder().reduction_path(ProblemType(self.qp), [QpSolver])
self.assertEquals(2, len(path))
self.assertEquals(path[1], QpMatrixStuffing)
def test_QPcanon_postconditions(self):
pa = ProblemType(self.qp)
pc = Qp2SymbolicQp.postconditions(pa.type)
self.assertEquals(True, (Minimize, is_quadratic, True) in pc)
self.assertEquals(True, (NonPos, are_arguments_affine, True) in pc)
self.assertEquals(False, any(type(c[0]) == Zero for c in pc))
def test_QPcanon_type(self):
pa = ProblemType(self.qp)
self.assertEquals(True, (Minimize, is_quadratic, True) in pa.type)
self.assertEquals(True, (NonPos, is_affine, True) in pa.type)