CPXgetcallbacklp

Usage

Mixed Integer Users Only

The routine CPXgetcallbacklp() is used to get the pointer to the MIP problem that is in use when the user-written callback function is called. It is the original MIP if CPX_PARAM_MIPCBREDLP is set to CPX_OFF, otherwise it is the presolved MIP. In contrast, the function CPXgetcallbacknodelp() returns a pointer to the node subproblem, which is an LP. Generally, this pointer may be used only in CPLEX Callable Library query routines, such as CPXsolution() or CPXgetrows().

This routine may be called only when the value of the wherefrom argument is one of CPX_CALLBACK_MIP, CPX_CALLBACK_MIP_BRANCH, CPX_CALLBACK_MIP_INCUMBENT, CPX_CALLBACK_MIP_NODE, CPX_CALLBACK_MIP_HEURISTIC, CPX_CALLBACK_MIP_SOLVE, or CPX_CALLBACK_MIP_CUT.

The routine returns a zero on success, and a nonzero if an error occurs.

int CPXgetcallbacklp (CPXCENVptr env, void *cbdata, int wherefrom, CPXCLPptr *lp_p);

Arguments

The pointer to the CPLEX environment, as returned by one of the CPXopenCPLEX routines.

The pointer passed to the user-written callback. This parameter must be the value of cbdata passed to the user-written callback.

An integer value indicating from where the user-written callback was called. The parameter must be the value of wherefrom passed to the user-written callback.

A pointer to a variable of type CPXLPptr to receive the pointer to the LP problem object, which is a MIP.

status = CPXgetcallbacklp (env, cbdata, wherefrom, &origlp);

See Also