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[Trac #165] Command line CBC reports "Optimal solution found", but the solution file reports "Status unknown" #45

Open s-c-e opened 5 years ago

s-c-e commented 5 years ago

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Attachments: https://github.com/s-c-e/cbc-trac-migration-attachments/blob/master/trac-ticket-165.zip

Hello,

I have a problem where the command line reports "Optimal solution found", with a reasonable objective value, but in the solution file "Status unknown" is reported. CBC has been compiled with MinGW 4.9.2, and works quite well with many other problems. The command line parameters are:

cbc -import pcbc.lp -solve -solution pcbc.sol -quit

By using:

cbc -import pcbc.lp -perturbation off -solve -solution pcbc.sol -quit

I get rid of some infeasibility warnings, the problem get solved to the same exact objective, but the solution file now is correct, so probably it is just a minor problem in the output procedure.

Attached the sample problem.

Thanks in advance for your attention, and thanks also for the excellent work.