[Scip] adding constraints within pricer redcost method

Gerald Gamrath gamrath at zib.de
Wed Apr 17 15:39:33 MEST 2013


Hi Andreas,

from what I can see in the code, all initial constraints should be added
after each pricing round. You should not need an extra parameter for
that and your constraint properties look ok.

So I guess we need to do some more debugging. Please add a "#define
SCIP_DEBUG" at top of src/scip/solve.c and src/scip/cons_linear.c for
additional debugging output. Additionally, you could remove the two if's
around
SCIP_CALL( SCIPdispPrintLine(set, messagehdlr, stat, NULL, TRUE) );
in priceLoop() in SCIPsolve.c in order to get an output line after each
pricing call.

Please run again with these changes and send me the output (don't send
it to the list, it might be quite large).

Best,
Gerald


On 17.04.2013 14:02, Andreas Gebauer wrote:
> Hi all,
>
> I'm still having trouble with adding constraints dynamically in the pricer redcost method.
> The linear constraints are added to the problem immediately but the corresponding rows are not.
> So the next LP-Loop produces infeasible solutions but does not notice it.
>
> The properties of the corresponding constraints are as follows:
> cons is active, added, checked, not deleted, not dynamic, enabled, enforced, global, inProb, initial, not local, locked, not lockedNeg, lockedPos, Modifiable, not obsolete, not original, propagated, propagationEnabled, not removable, separated, separationEnabled, not stickingAtNode, transformed
>
> The constraints are created with
>   SCIP_CALL(SCIPcreateConsLinear(scip, &cons, consname.str().c_str(), 0, NULL, NULL, 0.0,0.0, TRUE, TRUE, TRUE, TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE));
>
> Nevertheless, there is discrepancy of the numbers of rows and cons.
>
> I guess it is a problem with some parameters of the linear constraint handler but I don't know the magic trick.
> Does anybody has a hint?
>
> Thanks!
> Best regards,
> Andreas
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