[Scip] Column generation, meaning of the output from CPLEX after a column is added

[Gerald Gamrath]

Hi Xavier,

I can only guess what it means: Probably, the steepest edge norm for the
new column is computed, because we use the steepest edge pricing method
within CPLEX by default. Is there any more output? But probably the time
is spent for solving the LP after the norms were initialized, CPLEX does
not always print output for that.

You can also try to change the CPLEX pricing method to something else,
e.g., devex pricing by setting the parameter "lp/pricing = d" and see
how this changes the behavior.

Best,
Gerald

On 11.03.2014 16:49, Xavier Schepler wrote:
> Hi,
>
> What does the following message mean :
>
> Reinitializing primal norms . . .
> Computed 1 new norms.
> Initializing primal norms rowwise . . .
>
> produced each time a column is added ?
> So much time (several seconds) is spent between each of this line.
> It appears at each column generation iteration.
> Then the LP is re-optimized.
>
> Best,
>
> Xavier
>
>
>
>
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