[Scip] Add and delete variable in probing

[Gerald Gamrath]

Hi Jonas,

do you want to tighten the constraints or relax them? If you only want 
to tighten them, I would suggest you just add the variables at the 
beginning, and then tighten the bounds of the auxiliary variables during 
probing, which will automatically be undone later.

If you want to relax the constraints, can you explain why you want to do 
this?

Currently, variables priced during probing mode are not automatically 
deleted after the probing node was processed, but this could probably be 
added, even if it does not guarantee that the variable is really deleted 
(you cannot delete it if the variable already occurs in some global data 
like a solution or conflict.

Best,
Gerald

Am 10.01.2014 15:12, schrieb Jonas Witt:
> Hi all,
>
> I want to change the rhs/lhs of some constraints during probing (it 
> has to be probing not diving!). Since this is not possible, I would 
> like to add a new variable to each constraint which I want to change. 
> Then I want to fix this variable in probing mode via 
> SCIPfixVarProbing(), which implicitly changes the rhs and lhs of the 
> constraint. In the end I want to solve the probing LP, exit the 
> probing mode and delete the created variables.
>
> How can I achieve this? Should I mark the variables to be deletable by 
> SCIPvarMarkDeletable() and add the variables to the problem during 
> probing in order to automatically delete the variables after the 
> probing node was processed?
>
> Best regards,
> Jonas
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