[SCIP] FORCE BRANCHING WITH CONTINUOUS VARIABLES

[Gerald Gamrath]

Hi Diego,

branching is done as part of the enforcement of LP (or pseudo) 
solutions. The enforcement callback of the integrality constraint 
handler calls the branching rules by decreasing priority. But any other 
constraint handler with active constraints can also do branching.

Thus, you can implement your own constraint handler which checks whether 
you need to do branching in the CONSENFOLP callback. You should add one 
constraint of this handler which stores the data needed to check 
feasibility.

Note that the enforcement callbacks of constraint handler are called in 
decreasing priority until one did perform a branching. So you could even 
mix branching on integer variables with other branching by your own 
constraint handler. If your constraint handler has a positive priority, 
it will always be called before the integer variable branching, 
otherwise afterwards. In your case, however, I would recommend to just 
define your variables as continuous.

Best,
Gerald

On 04.03.2016 17:23, dponce at us.es wrote:
>
> Hello list,
>
> I have to develope a Ryan and Foster Branching similar to the 
> binpacking one. The difference is that when I finish my branching I 
> cannot assure integrality on the variables. But I don't have to, since 
> I'm able to build a solution for my problem easily.
>
> It is possible to force the problem to go to the branching when I 
> define my variables as continuous? If not, is there a way to just use 
> my branching and no the default branching?
>
> Best.
>
> Diego.
>
>
>
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