> I would like to generate a dual ray when the first phase of the > primal simplex algorithm cannot reach the zero objective value. The > auxiliary optimization problem's dual solution is exactly an > infeasible ray (dual unbounded ray), but I do not know, how can I > retrieve it in glpk. Could you advice some solution?
You may call the dual simplex: glp_smcp parm; parm.meth = GLP_DUAL; glp_simplex(lp, &parm); and then check the solution status with glp_get_status. If it is GLP_NOFEAS, you may determine a basic variable which causes dual unboundedness with the routine lpx_get_ray_info. For detail please see the reference manual. _______________________________________________ Help-glpk mailing list Help-glpk@gnu.org http://lists.gnu.org/mailman/listinfo/help-glpk
