[SCIP] [Scip] Question about column generation in scip

[M. Farham]

Hi all,

Same question here.
But I am not sure if I am giving the initial columns correctly. What I do
is to create a variable and add its coefficients to the objective function
and corresponding constraints before calling the pricer. Is this ok, or
should I price this variable and add it in the pricing stage?

Bests,

Saleh

On Tue, Mar 10, 2015 at 12:36 AM, Abdelkader Ouali <oualiaek at hotmail.fr>
wrote:

> Hi all,
>
> I have implemented branch-and-price using Scip,
> and launch it to solve short examples before attacking big ones.
> I noticed that when I give an optimal solution as initial columns
> for the master or also during the solving, the pricing process generates
> unused  columns, which are in final all zero (because they not participate
> in optimal solution).
> So, I wonder why the pricing generates columns while an already optimal
> solution was given, is it due to duals given by Scip or ... ?
>
> Thanks for any help
> With regards
> ---
> A. Ouali
>
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>


-- 
M Saleh F
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