Clp.old icon indicating copy to clipboard operation
Clp.old copied to clipboard

[TRAC] OsiClp solver status bug

Open bernalde opened this issue 6 years ago • 1 comments

Moved from TRAC as part of COIN fORgery: https://projects.coin-or.org/Clp/ticket/77 image OSICLP trunk version fails to update the solver status on some cases. Please compile and run the attached solve.cpp with the provided input file node7.mps.

Run solve node7.mps OSICLP claims problem is solved optimally even though it is infeasible. I think OSICLP/CLP realizes the problem is infeasible but just does not update the solver status properly.

Output:

Coin0008I BLANK read with 0 errors
Calling initialSolve()...
Calling resolve()...
Optimal solution found. Obj Value: 12035.2
Update upper bound of variable 1 to 0.
Calling resolve...
Optimal solution found. Obj Value: 12035.2
lower bound of x[1]: 0
upper bound of x[1]: 0
optimal value of x[1]: 0.0294118
D'oh!

Attachments: https://projects.coin-or.org/Clp/attachment/ticket/77/node7.mps https://projects.coin-or.org/Clp/attachment/ticket/77/solve.cpp Comment: This defect appears in release 1.16.0 but not in release 1.15.12

bernalde avatar Oct 16 '18 20:10 bernalde

Unable to reproduce with trunk

jjhforrest avatar Nov 12 '18 15:11 jjhforrest