Callbacks

INDEX PREVIOUS NEXT

• during the presolve process;
• once per iteration in a linear programming or quadratic programming routine; and
• at various points, such as before node processing, in a mixed integer optimization.

In addition, callback functions can call CPXgetcallbackinfo to retrieve information about the progress of an optimization algorithm. They can also return a value to indicate whether an optimization should be aborted. CPXgetcallbackinfo and certain other callback-specific routines are the only ones of the Callable Library that a user-defined callback may call. (Of course, calls to routines not in the Callable Library are permitted.)

Using Optimization Callbacks explores callback facilities in greater detail, and Advanced MIP Control Interface discusses control callbacks in particular.