Control Callbacks for IloCplex

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Control Callbacks for IloCplex

Control callbacks allow you to control the branch & cut search during the optimization of MIP problems. The following control callbacks are available for IloCplex:

The node callback allows you to query and optionally overwrite the next node ILOG CPLEX will process during a branch & cut search.
The solve callback allows you to specify and configure the optimizer option to be used for solving the LP at each individual node.
The cut callback allows you to add problem-specific cuts at each node.
The heuristic callback allows you to implement a heuristic that tries to generate a new incumbent from the solution of the LP relaxation at each node.
The branch callback allows you to query and optionally overwrite the way ILOG CPLEX will branch at each node.
The incumbent callback allows you to check and optionally reject incumbents found by ILOG CPLEX during the search.

These callbacks are implemented as an extension of the diagnostic callback class hierarchy. This extension is shown below along with the macro names for each of the control callbacks (see Diagnostic Callbacks for a discussion of how macros and callback implementation classes relate).

Again, the callback class hierarchy for Java is exactly the same, but the class names differ, in that there is no I at the end. For example, the corresponding Java implementation class for IloCplex::BranchCallbackI is IloCplex.BranchCallback.

Similar to the class IloCplex::CallbackI (IloCplex.Callback), the class IloCplex::ControlCallbackI (IloCplex.ControlCallback) is not provided for deriving user callback classes, but instead for defining the common interface for its derived classes. This interface provides methods for querying information about the current node, such as current bounds or solution information for the current node. See the class IloCplex::ControlCallbackI (IloCplex.ControlCallback) in the ILOG CPLEX Reference Manual for more information.

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