def test_expected_two_segment_cut(self):
m = models.twoSegments_SawayaGrossmann()
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
TransformationFactory('gdp.cuttingplane').apply_to(m, bigM=1e6,
verbose=True)
self.check_expected_two_segment_cut(m)
def test_expected_two_segment_cut_fme(self):
m = models.twoSegments_SawayaGrossmann()
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
TransformationFactory('gdp.cuttingplane').apply_to(
m, bigM=1e6, create_cuts=create_cuts_fme, post_process_cut=None)
self.check_expected_two_segment_cut(m)
def test_integer_arithmetic_cuts_valid_inf_norm(self):
m = models.twoSegments_SawayaGrossmann()
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
TransformationFactory('gdp.cuttingplane').apply_to(
m, bigM=1e6, create_cuts=create_cuts_fme, norm=float('inf'),
post_process_cut=None, do_integer_arithmetic=True)
cuts = m._pyomo_gdp_cuttingplane_transformation.cuts
self.check_expected_two_segment_cut_exact(cuts)
def test_non_unique_cut_name_error(self):
m = models.twoSegments_SawayaGrossmann()
self.assertRaisesRegex(
GDP_Error, "cuts_name was specified as 'disj1', but this is "
"already a component on the instance! Please "
"specify a unique name.",
TransformationFactory('gdp.cuttingplane').apply_to,
m,
cuts_name="disj1")
def test_two_segment_cuts_valid(self):
m = models.twoSegments_SawayaGrossmann()
# add stupid variable to make sure that we don't require everything in
# rBigM to be useful.
m.will_be_stale = Var()
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
TransformationFactory('gdp.cuttingplane').apply_to(m, bigM=1e6)
self.check_two_segment_cuts_valid(m)
def test_expected_two_segment_cut_inf_norm(self):
m = models.twoSegments_SawayaGrossmann()
# make sure this is fine if dual Suffix is already on model
m.dual = Suffix(direction=Suffix.IMPORT)
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
TransformationFactory('gdp.cuttingplane').apply_to(
m, bigM=1e6, norm=float('inf'), post_process_cut=None)
self.check_expected_two_segment_cut(m)
def test_deactivated_objectives_ignored(self):
m = models.twoSegments_SawayaGrossmann()
# add an opposite direction objective, but deactivate it
m.another_obj = Objective(expr=m.x - m.disj2.indicator_var,
sense=maximize)
m.another_obj.deactivate()
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
TransformationFactory('gdp.cuttingplane').apply_to(m, bigM=1e6,
verbose=True)
self.check_expected_two_segment_cut(m)
def test_cuts_named_correctly(self):
m = models.twoSegments_SawayaGrossmann()
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
TransformationFactory('gdp.cuttingplane').apply_to(
m, bigM=1e6, create_cuts=create_cuts_fme, cuts_name="perfect_cuts",
post_process_cut=None, do_integer_arithmetic=True)
cuts = m.component("perfect_cuts")
self.assertIsInstance(cuts, Constraint)
self.assertIsNone(
m._pyomo_gdp_cuttingplane_transformation.component("cuts"))
self.check_expected_two_segment_cut_exact(cuts)
def test_two_segment_cuts_valid_inf_norm(self):
m = models.twoSegments_SawayaGrossmann()
# make sure this is fine if there is a random component called dual:
# Note that this not only tests that we handle the creating of the dual
# Suffix correctly, but also that we handle a stupid variable in rBigM
# that will come back stale and really shouldn't be in the separation
# problem.
m.dual = Var()
# have to make M big for the bigm relaxation to be the box 0 <= x <= 3,
# 0 <= Y <= 1 (in the limit)
# This one has to post process, but it is correct with the default
# settings.
TransformationFactory('gdp.cuttingplane').apply_to(
m, bigM=1e6, norm=float('inf'))
self.check_two_segment_cuts_valid(m)