- Procedure GMP::Instance::SetCallbackTime(GMP, callback)¶
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 )
The procedure returns 1 on success, or 0 otherwise.
The callback procedure should have exactly one argument; a scalar input element parameter into the set
CallbackTimecallback procedure should have a return value of
0, 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.
CallbackTimecallback 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.