ILOG CPLEX C++ API 9.0 Reference Manual

IloCplex::ControlCallbackI
Description
See Also
Methods
This class defines the common application programming interface (API) for the
following classes that allow you to control the MIP search:
◆
◆
◆
IloCplex::SolveCallbackI
IloCplex::CutCallbackI
IloCplex::HeuristicCallbackI
◆ IloCplex::BranchCallbackI
An instance of one of these classes represents a user-written callback that intervenes in
the search for a solution at a given node in an application that uses an instance of
IloCplex to solve a mixed integer program (MIP). Control callbacks are tied to a
node. They are called at each node during IloCplex branch & cut search. The user
never subclasses the IloCplex::ControlCallbackI class directly; it only
defines the common interface of thosee listed callbacks.
In particular, SolveCallbackI is called before solving the node relaxation and
optionally allows substitution of its solution. IloCplex does this by default. After the
node relaxation has been solved, either by an instance of SolveCallbackI or by
IloCplex, the other control callbacks are called in the following order:
◆
◆
IloCplex::CutCallbackI
IloCplex::HeuristicCallbackI
◆ IloCplex::BranchCallbackI
If the cut callback added new cuts to the node relaxation, the node relaxation will be
solved again using the solve callback, if used. The same is true if IloCplex generated
its own cuts.
The methods of this class are protected and its constructor is private; you cannot directly
subclass this class; you must derive from its subclasses.
If an attempt is made to access information not available to an instance of this class, an
exception is thrown.
IloCplex, IloCplex::Callback, IloCplex::CallbackI,
ControlCallbackI::IntegerFeasibility,
IntegerFeasibilityArray, IloCplex::MIPCallbackI
protected IloNum getDownPseudoCost(const IloIntVar var)
This method returns the current pseudo cost for branching downward on the variable
var.
protected IloNum getDownPseudoCost(const IloNumVar var)
ILOG CPLEX C++ API 9.0 REFERENCE M ANUAL 109