[SCIP] Correction: Reliability Branching

[Jakob Witzig]

Hi Ahmed,

sorry for the confusing description of the parameters. Sometimes a look 
into the source helps to see the differences, e.g., 
http://scip.zib.de/doc/html/branch__relpscost_8h_source.php, lines 625 
-- 627 and 892 -- 919.

The first two parameters are used to calculate the maximal number of 
strong branching iterations for the current node, where sbiterquot is 
multiplied with the total number of LP iterations done so far. 
Afterwards, an offset, i.e., sbiterofs, and the number of strong 
branching LP iterations used in the root node are added.

The third parameter is used to calculate the number of strong branching 
iterations for a single strong branching candidate.

I hope this short explanation makes the differences a bit more clear.

Best,
Jakob

Am 07.01.2016 um 00:31 schrieb Ahmed Ibrahim:
> For the third one I meant branching/relpscost/inititer
> ------------------------------------------------------------------------
> *From:* Scip [scip-bounces at zib.de] on behalf of Ahmed Ibrahim
> [Ahmed.Ibrahim at umanitoba.ca]
> *Sent:* Wednesday, January 06, 2016 4:36 PM
> *To:* scip at zib.de
> *Subject:* [SCIP] Reliability Branching
>
> Hi SCIP community,
> Can any one help me clear the confusion between the following parameters
> in reliability branching:
>
>  1. branching/relpscost/sbiterofs: explained in
>     'http://scip.zib.de/doc/html/PARAMETERS.php' as the additional
>     number of allowed strong LP iterations
>  2. branching/relpscost/sbiterquot: explained in
>     'http://scip.zib.de/doc/html/PARAMETERS.php' as the amaximal
>     fraction of strong branching LP iterations compared to node
>     relaxation LP iterations
>  3. branching/relpscost/initcand: explained in
>     'http://scip.zib.de/doc/html/PARAMETERS.php' as the iteration limit
>     for strong branching initializations for pseudocosts entries
>
> To me the three seem to do the same thing, which is deciding the maximum
> number of strong branching LP iterations . I don't understand how they
> are different?
>
> Regards,
> Ahmed
>
>
> _______________________________________________
> Scip mailing list
> Scip at zib.de
> http://listserv.zib.de/mailman/listinfo/scip
>


-- 
Jakob Witzig

Konrad-Zuse-Zentrum für
Informationstechnik Berlin (ZIB)

Division Mathematical Optimization and Scientific Information
Research Group Mathematical Optimization Methods

Takustrasse 7
14195 Berlin

Tel. : +49 (0)30 84185-416
Fax  : +49 (0)30 84185-269
email: witzig at zib.de