def relax_objective(self, problem, objective):
result = self.relax_expression(problem,
objective.root_expr,
side=RelaxationSide.UNDER)
new_objective = Objective(objective.name, result.expression,
objective.original_sense)
return RelaxationResult(new_objective, result.constraints)
def relax_objective(self, problem, objective):
self._objective_count += 1
if self._objective_count > 1:
raise ValueError(
'Apply LinearRelaxation to multiobjective problem')
new_variable = Variable('_objvar', None, None, Domain.REAL)
new_objective_expr = LinearExpression([new_variable], [1.0], 0.0)
new_objective = Objective(
objective.name,
new_objective_expr,
objective.original_sense,
)
under_result = self.relax_expression(problem, objective.root_expr)
new_cons_expr = SumExpression([
under_result.expression,
LinearExpression([new_variable], [-1.0], 0.0),
])
new_cons = Constraint('_obj_{}'.format(objective.name), new_cons_expr,
None, 0.0)
under_result.constraints.append(new_cons)
return RelaxationResult(new_objective, under_result.constraints)
def relax_constraint(self, problem, constraint):
cons_idx = self._constraint_idx[constraint.name]
u = self._u[cons_idx]
minus_u = LinearExpression([u], [-1], 0.0)
new_expr = SumExpression([constraint.root_expr, minus_u])
new_constraint = Constraint(constraint.name, new_expr,
constraint.lower_bound,
constraint.upper_bound)
return RelaxationResult(new_constraint, [])
def relax_constraint(self, problem, constraint):
if constraint.lower_bound is None:
side = RelaxationSide.UNDER
elif constraint.upper_bound is None:
side = RelaxationSide.OVER
else:
side = RelaxationSide.BOTH
result = self.relax_expression(problem,
constraint.root_expr,
side=side)
new_constraint = Constraint(constraint.name, result.expression,
constraint.lower_bound,
constraint.upper_bound)
new_constraint.metadata = constraint.metadata
return RelaxationResult(new_constraint, result.constraints)
def relax_constraint(self, problem, constraint):
result = self.relax_expression(problem, constraint.root_expr)
new_constraint = Constraint(constraint.name, result.expression,
constraint.lower_bound,
constraint.upper_bound)
return RelaxationResult(new_constraint, result.constraints)
def relax_constraint(self, problem, constraint):
return RelaxationResult(constraint)
def relax_objective(self, problem, objective):
return RelaxationResult(objective)
def relax_objective(self, problem, objective):
result = self.relax_expression(problem, objective.root_expr)
new_objective = Objective(objective.name, result.expression,
objective.sense)
return RelaxationResult(new_objective, result.constraints)
def relax_constraint(self, problem, constraint):
if constraint.name != 'cons2':
return RelaxationResult(constraint)
w = Variable('aux', None, None, None)
return RelaxationResult(Constraint('aux_cons2', w, None, None))
def relax_objective(self, problem, objective):
coefficients = np.ones(problem.num_constraints)
expr = LinearExpression(self._u, coefficients.tolist(), 0.0)
new_objective = Objective('objective', expr, Sense.MINIMIZE)
return RelaxationResult(new_objective, [])