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This is an advanced routine. Advanced routines typically demand a thorough understanding of the algorithms used by ILOG CPLEX. Thus they incur a higher risk of incorrect behavior in your application, behavior that can be difficult to debug. Therefore, ILOG encourages you to consider carefully whether you can accomplish the same task by means of other Callable Library routines instead.
The routine CPXgetcallbacknodeintfeas
is used to get
information for each variable on whether or not the variable is integer
feasible in the node subproblem. It can be used in a user-written callback
during MIP optimization. The information is from the original problem if
CPX_PARAM_MIPCBREDLP
is set to CPX_OFF
. Otherwise,
they are from the presolved problem.
Example
status = CPXgetcallbacknodeintfeas(env, cbdata, wherefrom, feas, 0, cols-1);
See admipex1.c
and admipex2.c
in the standard distribution.
This routine may be called only when the value of the
wherefrom
argument is one of the following:
CPX_CALLBACK_MIP
,
CPX_CALLBACK_MIP_BRANCH
,
CPX_CALLBACK_MIP_INCUMBENT
,
CPX_CALLBACK_MIP_NODE
,
CPX_CALLBACK_MIP_HEURISTIC
, or
CPX_CALLBACK_MIP_CUT
.
CPX_INTEGER_FEASIBLE | 0 | variable j+begin is integer-valued |
CPX_INTEGER_INFEASIBLE | 1 | variable j+begin is not integer-valued |
CPX_IMPLIED_INTEGER_FEASIBLE | 2 | variable j+begin may have a fractional value in the current solution, but it will take on an integer value when all integer variables still in the problem have integer values. It should not be branched upon. |
env | A pointer to the CPLEX environment, as returned by |
cbdata | The pointer passed to the user-written callback. This parameter must be the value of |
wherefrom | An integer value indicating from where the user-written callback was called. The parameter must be the value of |
feas | An array to receive integer feasibility information for the node subproblem. This array must be of length at least ( |
begin | An integer indicating the beginning of the range of integer feasibility information to be returned. |
end | An integer indicating the end of the range of integer feasibility information to be returned. |