ILOG CPLEX C++ API 9.0 Reference Manual

IloCplex::NodeCallbackI
protected void
protected void
selectNode(NodeId)
selectNode(int)
Inherited methods from IloCplex::MIPCallbackI
MIPCallbackI::getBestObjValue, MIPCallbackI::getCutoff,
MIPCallbackI::getDirection, MIPCallbackI::getDirection,
MIPCallbackI::getIncumbentObjValue, MIPCallbackI::getIncumbentValue,
MIPCallbackI::getIncumbentValue, MIPCallbackI::getIncumbentValues,
MIPCallbackI::getIncumbentValues, MIPCallbackI::getMyThreadNum,
MIPCallbackI::getNcliques, MIPCallbackI::getNcovers,
MIPCallbackI::getNdisjunctiveCuts, MIPCallbackI::getNflowCovers,
MIPCallbackI::getNflowPaths, MIPCallbackI::getNfractionalCuts,
MIPCallbackI::getNGUBcovers, MIPCallbackI::getNimpliedBounds,
MIPCallbackI::getNiterations, MIPCallbackI::getNMIRs,
MIPCallbackI::getNnodes, MIPCallbackI::getNremainingNodes,
MIPCallbackI::getObjCoef, MIPCallbackI::getObjCoef,
MIPCallbackI::getObjCoefs, MIPCallbackI::getObjCoefs,
MIPCallbackI::getPriority, MIPCallbackI::getPriority,
MIPCallbackI::getUserThreads, MIPCallbackI::hasIncumbent
Inherited methods from IloCplex::CallbackI
CallbackI::abort, CallbackI::duplicateCallback, CallbackI::getEnv,
CallbackI::getModel, CallbackI::getNcols, CallbackI::getNQCs,
CallbackI::getNrows, CallbackI::main
Description
An instance of the class IloCplex::NodeCallbackI represents a user-written
callback in an application that uses an instance of IloCplex to solve a mixed integer
programming problem (a MIP). The methods of this class enable you (from a userderived
callback class) to query the instance of IloCplex about the next node that it
plans to select in the branch & cut search, and optionally to override this selection by
specifying a different node.
When an instance of this callback executes, the invoking instance of IloCplex still
has n = getNremainingNodes (inherited from IloCplex::MIPCallbackI)
nodes left to process. These remaining nodes are numbered from 0 (zero) to (n - 1).
For that reason, the same node may have a different number each time an instance of
NodeCallbackI is called. To identify a node uniquely, an instance of IloCplex
also assigns a unique NodeId to each node. That unique identifier remains unchanged
throughout the search. The method getNodeId(int i) allows you to access the
ILOG CPLEX C++ API 9.0 REFERENCE M ANUAL 188