Procedure GMP::Instance::SetCallbackIterations(GMP, callback, value)

# GMP::Instance::SetCallbackIterations¶

The procedure GMP::Instance::SetCallbackIterations installs a callback procedure that is called after a specified number of iterations.

GMP::Instance::SetCallbackIterations(
GMP,            ! (input) a generated mathematical program
callback,       ! (input) an AIMMS procedure
[value]         ! (optional) number of iterations
)


## Arguments¶

GMP

An element in AllGeneratedMathematicalPrograms.

callback

A reference to a procedure in the set AllIdentifiers.

value

A scalar value indicating after which number of iterations the callback procedure should be called. The default value is 0.

## 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 CallbackIterations callback 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.

• The number of iterations can also be set by the CallbackIterations suffix of the symbolic mathematical program, but will be overruled if the value is not equal to 0.

• During a MIP solve, the iterations callback will be called irregularly by CPLEX, GUROBI and ODH-CPLEX (especially during the MIP phase).

• The iterations callback will be called less often if CPLEX uses dynamic search as the MIP Search Strategy instead of branch-and-cut.