On Mon, 21 Mar 2022, Andrew Makhorin wrote:
-------- Forwarded Message -------- From: Will Tipton <[email protected]> To: [email protected] Cc: John Rice <[email protected]> Subject: identifying infeasible problem without using the LP presolver Date: Mon, 21 Mar 2022 11:15:44 -0400
Running without the presolver usually works great. However, we can't rely on the results in this case, because the simplex algorithm returns an OK error code even when it fails to find a feasible solution.
If the presolver is not used, glp_simplex will return 0 iff it was able to do its job. That includes discovering that the problem has no solution. To get the desired information, use glp_get_status. If the presolver is used, glp_simplex will return 0 iff it was able to do its job and the presolver did not determine that the problem was primal or dual infeasible. -- Michael [email protected] Electic cars run on coal.
