[SCIP] Adding separating cuts at root node only

[Gerald Gamrath]

Hi Naga,

no, it cannot be disabled, because it is checking the feasibility of 
solutions and without it, the algorithm is not correct anymore, see 
https://www.scipopt.org/doc-7.0.1/html/CONS.php#CONSCHECK

Best,

Gerald

Am 15.07.20 um 19:32 schrieb Naga Venkata Chaitanya Gudapati - 
nagavenkata.gudapati at studio.unibo.it:
> Thanks a lot Filipe and Ambros,
>
> SCIP_DECL_CONSCHECK(scip_check) is being called again and again after after the branching starts. Is there a way to disable it once branching starts?
>
> Thanks a lot!
> Naga
>
> ________________________________________
> From: Scip <scip-bounces at zib.de> on behalf of Felipe Serrano <fserranom5 at gmail.com>
> Sent: Wednesday, July 15, 2020 6:49 PM
> To: SCIP mailing list
> Subject: Re: [SCIP] Adding separating cuts at root node only
>
> Hi
>
> In this particular example, notice also that the function findSubtour gets called in CONSCHECK as well!
>
> Best,
> Felipe
>
> On Wed, Jul 15, 2020 at 5:23 PM Ambros Gleixner <gleixner at zib.de<mailto:gleixner at zib.de>> wrote:
> Dear Naga,
>
> This could happen when a sub-SCIP heuristic is called in the tree.  You
> could check this by printing SCIPgetProbName(), since sub-SCIP
> heuristics typically append their name to the problem name of the
> original SCIP.
>
> Best,
> Ambros
>
>
> Am 15.07.20 um 16:51 schrieb Naga Venkata Chaitanya Gudapati -
> nagavenkata.gudapati at studio.unibo.it<mailto:nagavenkata.gudapati at studio.unibo.it>:
>> Hello SCIP community,
>>
>> I have created a constraint handler using the following piece of c++ code
>>
>> ObjConshdlr(scip, "subour", "subtour 3_constraints",
>>            1000000, -2000000, -2000000, 0, -1, 1, 0,
>>            FALSE, FALSE, TRUE, SCIP_PROPTIMING_BEFORELP, SCIP_PRESOLTIMING_FAST)
>>
>> I used the TSP example as foundation and followed the documentation here, https://www.scipopt.org/doc/html/classscip_1_1ObjConshdlr.php
>>
>> I am keeping sepafreq at 0 so that the cuts are only added at the root node. But I noticed that some of the functions of the constraint handler like findSubtour are still getting called after the branching starts. Is there something else I have to do?
>>
>> Thanks for the help,
>> Naga
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>> Scip at zib.de<mailto:Scip at zib.de>
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>>
> --
> Ambros Gleixner, Research Group Mathematical Optimization Methods at
> Zuse Institute Berlin, http://www.zib.de/gleixner
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