Originally posted by: SystemAdmin

Dear all,
I used "CPXgetcallbacknodeintfeas(env, cbdata, wherefrom, feas, 0, N1)" to check if some variables are integer feasible at each node of the B&B tree.

When I solved node lp and find some variables are fractional. But CPXgetcallbacknodeintfeas returns integer-feasible. Please see the following case
solution x_2_1 is 0.999996 feas 0
solution x_2_3 is 0.000000 feas 0
solution x_2_4 is 0.000004 feas 0
solution x_3_1 is 1.000000 feas 0
solution x_3_2 is 0.000000 feas 0
solution x_3_4 is 0.000000 feas 0
solution x_4_1 is 0.000014 feas 1
solution x_4_2 is 0.000001 feas 0
solution x_4_3 is 0.999985 feas 1

I am not sure I used CPXgetcallbacknodeintfeas correctly. Thanks.
Shaon
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Yes, this solution is integer-feasible. The tolerance for integer-feasibility (EpInt) defaults to 1e-5; all these values are within 1e-5 of either 1 or 0. Just round them.

Paul

Mathematicians are like Frenchmen: whenever you say something to them, they translate it into their own language, and at once it is something entirely different. (Goethe)
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Thanks, paul.

I have tried to set CPX_PARAM_EPINT to zero, using "status = CPXsetintparam (env, CPX_PARAM_EPINT, 0)" But some erro information came up:

CPLEX Error 1013: Bad parameter number to CPLEX parameter routine.

I checked the CPLEX manual and found that CPLEX allows us to set CPX_PARAM_EPINT to zero.
Shaon
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

Parameter CPX_PARAM_EPINT is of type double. You need to use CPXsetdblparam(), not CPXsetintparam().
#CPLEXOptimizers
#DecisionOptimization