[SCIP] SCIPmarkDoNotUpgradeConsLinear

[Gerald Gamrath]

Dear Luciana,

there is the method SCIPconsAddUpgradeLocks() in pub_cons.h now which 
allows you to disallow upgrading of constraints. Sorry, it seems that we 
forgot to document this replacement in the change log.

By the way: If you need dual values of a constraint in column 
generation, you probably want to possibly add variables to that 
constraint? In that case, the constraint should be marked as modifiable 
when creating it, and in this case, no upgrade should happen. Please be 
sure that you mark all constraint as modifiable to which variables may 
be added during solving, because otherwise, they may do reductions based 
on the assumption that the constraint won't change.

Best,
Gerald

Am 08.04.2016 um 01:07 schrieb Luciana Garcia Richter:
> Hi,
>
> I was looking an old version of scip which includes function 
> SCIPmarkDoNotUpgradeConsLinear. But later I realize this function was 
> removed in the last version. I didn't found any comment about this in 
> the change log.
>
> There is any reason this function was removed? There is any other way 
> to force scip to maintain specific constrains?
>
> I'm doing a column generation algorithm, and I need some constraint 
> not being removed because I need to get the dual value of them (if 
> they get removed I get a zero when I ask for dual value).
>
> Thanks in advance,
> Luciana
>
>
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