[Scip] Branching using SCIP solely as a CP Solver

[Alexander Schnell]

Hi again,

now i'm trying to implement a branching rule based on fixed values
depending on the variable names.
Though, i want to select the first variable from the candidates (which i
can get with SCIPgetPseudoBranchCands()), check its name and then select
a value s based on its name. Based on this value i will apply the
function SCIPbranchVarVal() to create three 
child nodes (x <= s-1, x == s and x >= s+1).

How can i tell SCIP that it should first analyze the node x == s?
Is there a possibility to set a branching priority for this node?

Best Regards,
Alexander Schnell


  


On Tue, 2011-11-15 at 16:22 -0500, Stefan Heinz wrote:
> Hi Alexander,
> 
> On 11/15/2011 10:30 AM, Alexander Schnell wrote:
> > Hi all,
> >
> > i'm using SCIP solely as a CP Solver by setting the corresponding
> > emphasis.
> >
> > The decision variables of my problem are integer.
> >
> > How could i add a branching rule
> > which at first branches on the variable with the shortest
> > lower bound and then starts by selecting the smallest value in the
> > respective domain?
> Such a branching rule does not exist in SCIP.
> > Do i have to implement a branching rule myself or is this
> > already included in SCIP?
> Yes you have to implement that rule. This is, however, not so hard. Just 
> follow the instruction:
> 
> http://scip.zib.de/doc/html/BRANCH.html
> 
> Basically, you only need to implement the method:
> 
> http://scip.zib.de/doc/html/BRANCH.html#BRANCHEXECPS
> 
> in case of a CP search.
> 
> To get the information you need you use the method 
> SCIPgetPseudoBranchCands()
> 
> http://scip.zib.de/doc/html/scip_8h.html#acb6423287e73b4c01172b888b615d5d6
> 
> to get all integer which are not fixed yet. Using the function 
> SCIPvarGetLbLocal() and SCIPvarGetUbLocal() you get access to the 
> (local) variable bounds.
> 
> Best Stefan
> > Best regards,
> >
> > Alexander Schnell
> >
> >
> >
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