ILOG CPLEX .NET Reference Manual

Cplex.HeuristicCallback Class

Base class for user-written callbacks injecting integer-feasible solutions during search.

For a list of all members of this type, see Cplex.HeuristicCallback Members.

System.Object
   ILOG.CPLEX.Cplex.Callback
      ILOG.CPLEX.Cplex.MIPCallback
         ILOG.CPLEX.Cplex.ControlCallback
            ILOG.CPLEX.Cplex.HeuristicCallback

public abstract class Cplex.HeuristicCallback : ControlCallback

Thread Safety

Public static (Shared in Visual Basic) members of this type are safe for multithreaded operations. Instance members are not guaranteed to be thread-safe.

Remarks

This is an advanced class.

Important:

Advanced classes typically demand a profound understanding of the algorithms used by ILOG CPLEX. Thus they incur a higher risk of incorrect behavior in your application, behavior that can be difficult to debug. Therefore, ILOG encourages you to consider carefully whether you can accomplish the same task by means of other classes instead.

This is the base class for user-written callbacks allowing you to inject integer-feasible solutions during the branch-and-cut search. During branching, the heuristic callback is called after each node subproblem has been solved, including any cuts that may have been newly generated. Before branching, at the root node, the heuristic callback is also called before each round of cuts is added to the problem and re-solved.

This callback class also provides support for implementing simplex-based heuristics for constructing solutions, by allowing you to change the bounds of variables and re-solve the node relaxation. Changing the bounds in the heuristic callback has no effect on the search after the callback has completed. This callback will be called after the node relaxation (including all cuts generated at that node) has been solved.

The constructor and methods of this class are protected to make sure that they are used only to derive a user-written callback class or to implement the main method in it.

Requirements

Namespace: ILOG.CPLEX

Assembly: ILOG.CPLEX (in ILOG.CPLEX.dll)

See Also

Cplex.HeuristicCallback Members | ILOG.CPLEX Namespace