My guess: You have a numerically unstable constraint. If x=20, y=10 and x - y + 1000000 * z = 1000000, then z = 0.99999. This is most likely 'close enough' for the solver to believe z is 1.0.
I'm not aware of any parameter using glpsol.exe to set a tolerance. Also, using '--exact' math also does not seem to help. -Marc -----Original Message----- From: Help-glpk <[email protected]> On Behalf Of Evgeny Kapun Sent: Sunday, June 27, 2021 5:51 PM To: [email protected] Subject: GLPK finds a solution that violates a constraint I have a model (attached). It includes a constraint: > s.t. contra : x - y + 1000000 * z <= 1000000; When I solve it (using glpsol --math model.sol), I get a solution with x=20, y=10 and z=1, which clearly violates that constraint. Why is it happening? ________________________________ This e-mail and any attachments may be confidential or legally privileged. If you received this message in error or are not the intended recipient, you should destroy the e-mail message and any attachments or copies, and you are prohibited from retaining, distributing, disclosing or using any information contained herein. Please inform us of the erroneous delivery by return e-mail. Thank you for your cooperation.
