[gecode-users] Multi-objective Model with Searchcombinators in Gecode

[Mohamed Rezgui]

Thank you very much for your answer. My problem is a pseudo bin
packing problem.
I would like to minimize a number of components of a certain sizes and
minimize the number of bins.
So I would like to do a lexicographic order on my multi-objective solutions.

Best Regards,
Mohammed REZGUI

2014-03-09 10:54 GMT+01:00 Guido Tack <tack at gecode.org>:
> Hi,
>
> could you clarify in what way you want to reuse the solution?
>
> Here's a combinator that first minimizes obj1, then maximizes obj2 keeping obj1 at the optimal value:
>
> annotation two_stage_bnb(var int: obj1, var int: obj2, ann: s) =
> let { svar int: best1 = 1000000,
>       svar int: best2 = 0 }
> in (
>   portfolio([and(post(obj1 < lv("best1"), and(s,assign(best1,obj1))),
>                  prune),
>              post(obj1=lv("best1"),
>                post(obj2 > lv("best2"), and(s,assign(best2,obj2)))
>              )]));
>
> Cheers,
> Guido
>
> On 9 Mar 2014, at 9:43 am, Mohamed Rezgui <kyo.alone at gmail.com> wrote:
>
>> Dear Sir,
>>
>> I would like to know how can I use searchcombinators in my
>> multi-objective model in FlatZinc.
>> I have 2 objectives. I minimize the first and I reuse the solution for
>> the minimization of the second objective.
>> Can you give me the good syntax in FlatZinc with searchcombinators to
>> do that please ?
>>
>> Best Regards,
>> Mohammed REZGUI
>> PhD Student
>>
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>



-- 
Cordialement,
Mohamed REZGUI