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Couenne - Another bug. For an infeasible problem, status shows locally solved. #67

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guanghuidatafuelx opened this issue Oct 31, 2022 · 1 comment

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@guanghuidatafuelx
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using AmplNLWriter, Couenne_jll
model = Model(() -> AmplNLWriter.Optimizer(Couenne_jll.amplexe))
...
optimize!(model)
println("primal_status=", primal_status(model))
println("termination_status=", termination_status(model))
print("raw_status(model)=", raw_status(model))

The couenne.opt file is
couenne.opt1.txt

The .lp file is
Couenne_model1.lp.txt

The .nl file is
Couenne_problem1.nl.txt

But this problem is actually infeasible because Spots_x[i]<=5, i=1,..,5.
4315 Spots_x[1] + 4315 Spots_x[2] + 4315 Spots_x[3] + 4315 Spots_x[4] + 4315 Spots_x[5] <=(4315)(5)(5)=107865.

So the constraint:

4315 Spots_x[1] + 4315 Spots_x[2] + 4315 Spots_x[3] + 4315 Spots_x[4] + 4315 Spots_x[5] ≥ 107876.0

will never be satisfied.

However, the status coming from the solver are:

primal_status(model)=FEASIBLE_POINT. termination_status(model)=LOCALLY_SOLVED

@guanghuidatafuelx
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A note: both SCIP and Juniper identified this problem as infeasible.

@guanghuidatafuelx guanghuidatafuelx changed the title Couenne - Another bug. For an infeasible problem, status shows locally soved. Couenne - Another bug. For an infeasible problem, status shows locally solved. Oct 31, 2022
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