[Scip] Strange behavior

[Stefan Heinz]

Hi Aurélien,

hard to tell where the issue is. You could write the pricer problem to a 
file via SCIPprintOrigProblem()

http://scip.zib.de/doc/html/scip_8h.html#ab0fbe8783e109c1f89e47c63103a70e0

and try to solve it with (plain) SCIP. Does that issue occur as well 
send us the instance. If that issue does not occur check if the 
constraints of the pricer problem are created "correctly". That mean, 
for example, that the check flag is set to TRUE.

Best Stefan

How do you create the constraint
On 06/15/12 15:25, Aurélien Questel wrote:
> Hi everyone,
> I'm currently working on a B&Price algorithm, using a second scip instance to solve my pricing problem.
>
> I have a strange behavior on some instances.
> Here is the output at the end of my pricer solving :
>
> SCIP Status        : problem is solved [optimal solution found]
> Solving Time (sec) : 0.03
> Solving Nodes      : 6
> Primal Bound       : -1.69360996591490e+10 (2 solutions)
> Dual Bound         : -1.69360996591490e+10
> Gap                : 0.00 %
>   [linear] <consCapa>: 0 <= +5<y_11->11>[B] +5<y_11->8>[B] +5<y_11->9>[B] +5<y_12->12>[B] +5<y_12->4>[B] +5<y_12->7>[B] +5<y_12->8>[B] +5<y_12->11>[B] +5<y_11->12>[B] +5<y_13->13>[B] +5<y_13->9>[B] +5<y_13->10>[B] +5<y_14->14>[B] +5<y_14->5>[B] +5<y_14->8>[B] +5<y_14->11>[B] +5<y_11->14>[B] +5<y_15->15>[B] +5<y_15->5>[B] +5<y_15->7>[B] +5<y_15->8>[B] +5<y_15->12>[B] +5<y_12->15>[B] +5<y_16->16>[B] +5<y_16->1>[B] +5<y_16->3>[B] +5<y_16->4>[B] +5<y_16->7>[B] +5<y_16->12>[B] +5<y_12->16>[B] +5<y_17->17>[B] +5<y_17->2>[B] +5<y_17->6>[B] +5<y_17->10>[B] +5<y_17->13>[B] +5<y_13->17>[B] +5<y_18->18>[B] +5<y_18->2>[B] +5<y_18->9>[B] +5<y_18->10>[B] +5<y_18->11>[B] +5<y_11->18>[B] +5<y_18->12>[B] +5<y_12->18>[B] +5<y_19->19>[B] +5<y_19->1>[B] +5<y_19->3>[B] +5<y_19->6>[B] +5<y_19->7>[B] +5<y_19->16>[B] +5<y_16->19>[B] +5<y_20->20>[B] +5<y_20->5>[B] +5<y_20->9>[B] +5<y_20->11>[B] +5<y_11->20>[B] +5<y_20->13>[B] +5<y_13->20>[B] +5<y_20->14>[B] +5<y_14->20>[B] <= 20;
> violation: right hand side is violated by 280
>
>
> I just can't figure how scip can state he found a "best solution" while a constraint of the original problem is violated ?
> (on this solution all my 'y' variables are set to 1, and other original constraints are violated too)
> Do you have any clue where my mistake can be ?
>
> It happens when I use all the plugins :
>      SCIP_CALL( SCIPincludeDefaultPlugins(_scipPricer) );
>      /* include 2 connexity constraint handlers */
> 	SCIP_CALL( SCIPincludeObjConshdlr(_scipPricer, new QRing2ConCliHdlr(_scipPricer, _Pd), FALSE) );
>
> Or only these ones :
>
>    SCIP_CALL( SCIPincludeConshdlrLinear(_scipPricer) );
>    SCIP_CALL( SCIPincludeConshdlrIntegral(_scipPricer) );
>    SCIP_CALL( SCIPincludeNodeselBfs(_scipPricer) );
>    SCIP_CALL( SCIPincludeReaderCip(_scipPricer) );
>      
>    /* DISPLAY *
>    SCIP_CALL( SCIPincludeDispDefault(scip) );
>    SCIP_CALL( SCIPincludeDialogDefault(scip) );
>    /* include 2 connexity constraint handlers */
>    SCIP_CALL( SCIPincludeObjConshdlr(_scipPricer, new QRing2ConCliHdlr(_scipPricer, _Pd), FALSE) );
>      
>
>
> Thanks for all
>
> Best,
>
> Aurélien Questel
>
>
> PS : the statistics are joint to this mail
>
>
>
>
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