
Procedure
GMP::Instance::
SetCallbackCandidate
(GMP, callback)¶
GMP::Instance::SetCallbackCandidate¶
The procedure GMP::Instance::SetCallbackCandidate
installs a
callback procedure that is called every time an incumbent solution is
found during the solution process of a MIP model. By using the procedure
GMP::SolverSession::RejectIncumbent
the incumbent solution can be
rejected. If GMP::SolverSession::RejectIncumbent
is not called
inside the CallbackCandidate
callback procedure then the incumbent
solution will be accepted and replace the best incumbent solution found
by so far.
GMP::Instance::SetCallbackCandidate(
GMP, ! (input) a generated mathematical program
callback ! (input) an AIMMS procedure
)
Arguments¶
 GMP
An element in
AllGeneratedMathematicalPrograms
. callback
A reference to a procedure in the set
AllIdentifiers
.
Return Value¶
The procedure returns 1 on success, or 0 otherwise.
Note
The callback procedure should have exactly one argument; a scalar input element parameter into the set
AllSolverSessions
.The
CallbackCandidate
callback procedure should have a return value of0, if you want the solution process to stop, or
1, if you want the solution process to continue.
If the return value is 0 (i.e., interrupt the solution process) then the incumbent solution will not be accepted!
To remove the callback the empty element should be used as the callback argument.
If an incumbent callback procedure is installed by using the procedure
GMP::Instance::SetCallbackIncumbent
, then that callback will be called after the candidate callback procedure if the incumbent solution is not rejected inside the candidate callback.A
CallbackCandidate
callback procedure will only be called when solving mixed integer programs with CPLEX.