Originally posted by: UserCplex

Hello,

In a lazy callback at some MIP node, CPLEX obtains a candidate integer feasible solution on applying some heuristic. This integer feasible objective function value is different from that node's LP relaxation solution value.

I am able to query the variable values associated with this candidate integer feasible solution in the lazy callback via 

status = CPXgetcallbacknodex(env, cbdata, wherefrom, cutinfo->x, 0, cutinfo->numcols - 1);

However, I am currently looping through cutinfo->x currently to figure out the objective function value related to this candidate integer solution. Is there a cplex function that provides this value directly?

I have looked at the following threads:

https://www.ibm.com/developerworks/community/forums/html/topic?id=a82ef24b-161d-4704-a4f9-74084a0d5999

but 

status = CPXgetcallbackinfo(env, cbdata, wherefrom, CPX_CALLBACK_INFO_BEST_INTEGER, &cbackobj);

returns garbage values in double cbackobj;

status = CPXgetcallbacknodeinfo(env, cbdata, wherefrom, 0, CPX_CALLBACK_INFO_NODE_OBJVAL, &cbackobj);

returns the LP relaxed solution objective function value at the current node, and not that of the candidate integer feasible solution.

status = CPXgetcallbacknodeinfo(env, cbdata, wherefrom, 0, CPX_CALLBACK_INFO_NODE_ESTIMATE, &cbackobj);

returns garbage values in cbackobj.

Thanks in advance.

Originally posted by: UserCplex

Just figured it out.

It is:

status = CPXgetcallbacknodeobjval(env, cbdata, wherefrom, &cbackobj);