[Cbc] Fwd: please help

[Christos]

Do you mean that i should include these words in the command /const char 
* argv2[]={"DAS","-solve","-quit"};  ?
/(Don't shoot, i am inexperienced)/
/
On 5/10/2012 19:07, Haroldo Santos wrote:
> Some options may accelerate (or slowdown) a lot. Heuristics usually 
> have a huge impact on the solution time. Try including
>
> cbc air04.mps.gz passF 100 solve
>
> Also, if you to not need the optimality proof you can disable cuts
>
> cbc air04.mps.gz passF 100 cuts off solve
>
> []'s
>
> On Fri, Oct 5, 2012 at 5:20 AM, Christos <chtsolak at gmail.com 
> <mailto:chtsolak at gmail.com>> wrote:
>
>     Thank you for your suggestion, i will check it and let you know.
>
>     But i think the problem is elsewhere.
>     When i solve the same problem with gams via cbc solver it takes
>     30-60 seconds, and not 60 minutes!
>     Why?
>
>
>     On 4/10/2012 17:57, Haroldo Santos wrote:
>>     On Thu, Oct 4, 2012 at 6:41 AM, Christos <chtsolak at gmail.com
>>     <mailto:chtsolak at gmail.com>> wrote:
>>
>>         I am asking you because i have a big problem. With very small
>>         alteration in data operation time goes from 9' to 65' !!!
>>
>>     This is  expected when solving Integer Programs if you are
>>     willing to proof the optimality.
>>     One thing you can do to exit more quickly, if you do not need the
>>     optimal solution (a good one may be enough), is to force the
>>     solver to quit after finding some solutions with the maxSolutions
>>     paramater.
>>
>>
>>         Any recommendations on the way i solve the model?
>>         Do you think that the above times are normal for such a model?
>>
>>
>>
>>         -------- Original Message --------
>>         Subject: 	please help
>>         Date: 	Wed, 03 Oct 2012 13:13:03 +0300
>>         From: 	Christos <chtsolak at gmail.com> <mailto:chtsolak at gmail.com>
>>         To: 	cbc at list.coin-or.org <mailto:cbc at list.coin-or.org>
>>         <cbc at list.coin-or.org> <mailto:cbc at list.coin-or.org>
>>
>>
>>
>>         Hi all,
>>
>>         i am a student in the final phase of the Milp model which i
>>         want to solve.
>>
>>         So, i have a milp model
>>         columns: 46614
>>         integers:  12540 (binary)
>>         rows:        40842
>>         nonzeros:117823
>>
>>         I tried these simple methods
>>         1.
>>         /solver1.loadProblem(numcols, numrows, start, index, value,
>>         collb, colub, obj, rowlb, rowub);
>>         solver1.initialSolve();
>>         solver1.branchAndBound() ;/
>>         2.
>>         /solver1.loadProblem(numcols, numrows, start, index, value,
>>         collb, colub, obj, rowlb, rowub);
>>         CbcModel model(solver1);
>>         CbcMain0(model);
>>         const char * argv2[]={"DAS","-solve","-quit"}; /-> _i don't
>>         know what this do._/
>>         CbcMain1(3,argv2,model);
>>
>>         /Since i am an amateur, can you help me?
>>         What method should i use to solve the model? 1,2 or something
>>         else?
>>         Any recommendations?
>>
>>         The 1st takes an hour and stops.
>>         The 2nd takes either 8' or 35' depending on the data.
>>
>>         Your help is much appreciated.
>>
>>         Christos
>>
>>
>>
>>         _______________________________________________
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>>
>>
>>
>>
>>     -- 
>>     =============================================================
>>     Haroldo Gambini Santos
>>     Computing Department - Universidade Federal de Ouro Preto - UFOP
>>     email: haroldo [at ] iceb.ufop.br <http://iceb.ufop.br>
>>     home/research page: www.decom.ufop.br/haroldo/
>>     <http://www.decom.ufop.br/haroldo/>
>>
>>     "Computer science is no more about computers than astronomy
>>     is about telescopes." Edsger Dijkstra
>>
>
>
>
>
> -- 
> =============================================================
> Haroldo Gambini Santos
> Computing Department - Universidade Federal de Ouro Preto - UFOP
> email: haroldo [at ] iceb.ufop.br <http://iceb.ufop.br>
> home/research page: www.decom.ufop.br/haroldo/ 
> <http://www.decom.ufop.br/haroldo/>
>
> "Computer science is no more about computers than astronomy
> is about telescopes." Edsger Dijkstra
>

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