ILOG CPLEX 11.0 User's Manual

◆◆●●Cplex.HeuristicCallback in the .NET APICPXsetheuristiccallback in the Callable Library (C API)The branch callback allows you to query and optionally overwrite the way ILOG CPLEXwill branch at each node.●●●●IloCplex::BranchCallbackI in the C++ APIIloCplex.BranchCallback in the Java APICplex.BranchCallback in the .NET APICPXsetbranchcallbackfunc in the Callable Library (C API)The incumbent callback allows you to check and optionally reject incumbents found byILOG CPLEX during the search.●●●●IloCplex::IncumbentCallbackI in the C++ APIIloCplex.IncumbentCallback in the Java APICplex.IncumbentCallback in the .NET APICPXsetincumbentcallbackfunc in the Callable Library (C API)Control Callbacks and Dynamic SearchControl callbacks are not compatible with dynamic search, a feature which explores asolution space in a way that departs from a conventional branch & cut tree.Normally, ILOG CPLEX chooses whether to apply dynamic search or conventionalbranch & cut based on characteristics of the model. To benefit from dynamic search, a MIPmust not include control callbacks. In the presence of control callbacks, ILOG CPLEX turnsoff dynamic search, issues a warning, and applies conventional branch & cut.If you want to avoid this warning in an application where control callbacks are present, youcan deliberately turn off dynamic search yourself by setting the MIP search parameter(MIPSearch, CPX_PARAM_MIPSEARCH) to 1 (one).Control Callbacks and Deterministic Parallel SearchControl callbacks are not compatible with deterministic parallel search, a feature whichexplores a solution space in a way that departs from a conventional branch & cut tree.In the presence of a control callback, ILOG CPLEX turns off deterministic parallel searchand invokes opportunistic parallel search instead, if your application is licensed for parallelMIP optimization.For more information about deterministic and opportunistic parallel MIP optimization, seeDeterminism of Results on page 493 and Parallel MIP Optimizer on page 497.ILOG CPLEX 11.0 — USER’ S MANUAL 453