ILOG CPLEX C++ API 9.0 Reference Manual

IloCplex::GoalI
Methods
public void abort()
Abort the optimization, that is, the execution of method solve currently in process.
public static IloCplex::Goal AndGoal(IloCplex::Goal goal1,
IloCplex::Goal goal2)
The static methods AndGoal all return a goal that pushes the goals passed as
parameters onto the goal stack in reverse order. As a consequence, the goals will be
executed in the order they are passed as parameters to the AndGoal function.
public static IloCplex::Goal BranchAsCplexGoal(IloEnv env)
This static function returns a goal that creates the same branches as the currently
selected built-in branch strategy of IloCplex would choose at the current node.
This goal allows you to proceed with the IloCplex search strategy, but keeps the
search under goal control, thereby giving you the option to intervene at any point.
This goal is also important when you use node evaluators while you use a built-in
branching strategy.
For example, consider the execute method of a goal starting like this:
if (!isIntegerFeasible())
return AndGoal(BranchAsCplexGoal(getEnv()), this);
// do something
It would do something only when IloCplex found a solution it considers to be
a candidate for a new incumbent. Note the test of integer feasibility before returning the
BranchAsCplexGoal. Without it, BranchAsCplex would be executed for a
solution IloCplex considers to be feasible, but IloCplex would not know how to
branch on it. An endless loop would result.
public virtual IloCplex::Goal duplicateGoal()
This virtual method must be implemented by the user. It must return a copy of the
invoking goal object. This method may be called by IloCplex when doing parallel
branch & cut search.
public virtual IloCplex::Goal execute()
This virtual method must be implemented by the user to specify the logic of the goal.
The instance of IloCplex::Goal returned by this method will be added to the goal
stack of the node where the invoking goal is being executed for further execution.
public static IloCplex::Goal FailGoal(IloEnv env)
This static method creates a goal that fails. That means that the branch where the goal is
executed will be pruned or, equivalently, the search is discontinued at that node and the
node is discarded.
ILOG CPLEX C++ API 9.0 REFERENCE M ANUAL 138