[Scip] Solving a subproblem within a B&B node

[Andrei Braga]

  Hello again,

  Reading the source code of SCIPcopy() method, I understood that it
creates a
new and independent SCIP instance, and copies into this instance information
from the original one. Then, I concluded that my concern about changes in a
sub-scip affecting the original SCIP instance makes no sense.

  I will keep going with my implementation, and report on further issues.

  Best regards,


On Fri, Apr 3, 2015 at 11:41 AM, Andrei Braga <andreisampaio at gmail.com>
wrote:

>   Dear all,
>
>   I am new to SCIP and I am trying to code a branch-and-price method. I'd
> like
> to ask you about how to implement the steps I describe below.
>
>   I've read about "diving" and "probing", but I think these aren't
> approaches
> suited for my purposes. I guess I should use a "sub-SCIP" (which I suppose
> is
> obtained through a call to the scipCopy() method), but I don't understand
> the
> details of the process (for example, changes made in the sub-SCIP affect
> the
> original SCIP instance?).
>
>   Let X be a subset of variables. When, after LP solving in a B&B node, all
> variables in X have integer value, I want to:
>   1) Create an copy of SCIP;
>   2) In this copy, delete some variables and constraints;
>   3) In this copy, replace the branching rules and the pricers by other
> ones;
>   4) In this copy, solve the "smaller" problem to optimality;
>   5) In the original SCIP instance, prune the B&B-node for optimality.
> I need that the deletions made in the SCIP copy do not affect the original
> SCIP instance.
>
>   Thank you very much,
>
> --
> Andrei Braga
>



-- 
Andrei Braga
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