- Procedure GMP::Instance::SetCallbackTime(GMP, callback)¶
GMP::Instance::SetCallbackTime¶
The procedure GMP::Instance::SetCallbackTime
installs a callback
procedure that is called after a specified number of (elapsed) seconds.
By default this callback procedure is called every two seconds.
GMP::Instance::SetCallbackTime(
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
CallbackTime
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.
To remove the callback the empty element should be used as the callback argument.
The
CallbackTime
callback procedure is supported by CPLEX, Gurobi, CBC, COPT, ODH-CPLEX, XA, CP Optimizer, CONOPT, Knitro, SNOPT and IPOPT.The number of (elapsed) seconds is determined by the general solvers option
Progress Time Interval
. This option also specifies the interval for updating the Progress Window during a solve. As a consequence, the information passed to this callback procedure will be the same as the information displayed in the Progress Window (except for small differences for the solving time).The time callback will be called less often if CPLEX uses dynamic search as the MIP Search Strategy instead of branch-and-cut. In that case the interval between two successive calls might sometimes be larger than the interval as specified by the option
Progress Time Interval
.
See also
The routines GMP::Instance::Generate
, GMP::Instance::SetCallbackAddCut
, GMP::Instance::SetCallbackAddLazyConstraint
, GMP::Instance::SetCallbackBranch
, GMP::Instance::SetCallbackCandidate
,
GMP::Instance::SetCallbackHeuristic
, GMP::Instance::SetCallbackIncumbent
and GMP::Instance::SetCallbackStatusChange
.