[SCIP] How to deactivate aging and avoid scip internal pricer ?

[Matheus Ota]

Hi All,

I think I'm passing through a similar problem. I've already set the
lp/colagelimit with:
SCIP_CALL(SCIPsetIntParam(scip, "lp/colagelimit", -1));

Still, when looking at my output, I see that a bunch of variables are
priced by the internal SCIP pricing:

Pricers            :   ExecTime  SetupTime      Calls       Vars
  problem variables:       1.08          -       1055       2775
  CVRPPricer       :      51.84       0.00        843       5017


Anyone have any tips here?

Thanks,
Matheus

2018-06-25 14:19 GMT-03:00 Gerald Gamrath <gamrath at zib.de>:

> Dear Sandra,
>
> I don't think that SCIPgetNPricevarsFound returns what you are interested
> in. As far as I can see, this is the total number of variables that were
> added to the to the pricestore. This may be variables "priced" by SCIP, but
> also the variables you priced, as well as all variables in your original
> formulation, that go through the pricestore once to enter the LP. Perhaps
> your original formulation is quite large?
>
> Setting the age limit to -1 should normally do the trick. There are other
> things like "lp/cleanupcols(root)", but those are disabled by default.
>
> When you look at the statistics after solving ("disp stat" in the
> interactive shell or SCIPprintStatistics()), you should see how many
> variables are really added by your pricer and by the internal SCIP pricing
> ("problem variables").  Is there a nonzero number for the latter?
>
> Best,
> Gerald
>
> On 25.06.2018 18:28, Sandra Ulrich Ngueveu wrote:
>
>> Hello,
>>
>> We are doing a Branch-and-Price with SCIP. Using function
>> "SCIPgetNPricevarsFound", we realized that a very higher number of
>> variables were "priced" by scip, compared to the number of columns that we
>> explicitely added (127253 instead of 475).
>>
>> We would like to deactivate such internal pricing (which according to
>> some forum is related to column aging) just to verify if the code would be
>> faster for our specific problem. We tried setting parameter lp/colagelimit
>> to -1, but the number of additional pricedvars declared by scip remained
>> unchanged.
>>
>> Could you please tell us if there is another parameter we could activate
>> or deactivate to achieve the desired behaviour ?
>>
>> Best regards,
>>
>> Sandra U. Ngueveu
>>
>>
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