[Cbc] solving time in C++ >> time in Gams

[Iain Dunning]

I wrote that guide.
Is it possible you are building your program in "Debug" mode? If the lib
files are large, it suggests they are being built with debugging
information...
Changing to "Release" mode could create speed ups of that order.

Cheers,
Iain

On Wed, Oct 10, 2012 at 4:39 AM, Christos <chtsolak at gmail.com> wrote:

>  In order to help you help me i compiled my code with this method:
> https://projects.coin-or.org/Cbc/wiki/VSSetup
>
> And as i can see lib files from repository are much smaller then these
> created with the above method.
>
> Is this matter?
>
>
> On 9/10/2012 23:00, Christos wrote:
>
> Very useful info!
>
> I downloaded Cbc-2.7.5-win64-intel11.1 and run cbc.exe in the bin folder.
> I used 2 methods-commands for solving, branchAndBound and solve.
>
> They both solved it almost 10 times faster!!!
>
> Now, to come to a solution, i need to know what's the differnece between
> solving with stand alone and simply by calling the solver via my code which
> was implemented in MS visual studio 2010..
>
> If you can help me with this, i would have find the solution to my big
> problem!
> I am waiting impatiently for your words.
>
> Thank you!
>
> On 9/10/2012 22:26, David Ibarra Gómez wrote:
>
>  You can find the CBC binaries here:
> https://projects.coin-or.org/CoinBinary or (here
> http://www.coin-or.org/download/binary/Cbc/). You can test different
> versions
>
>  From the shell you can call the executable binary. Then you just:
>
>  1. Import MPS file by just typing "import mpsfilename.mps"
> 2. and then you can solve it just typing "branchAndCut"
>
>  Then compare the time to solve with the API.
>
>  A random google search to find a "recipe" could be (at the end of page
> 6): http://wpweb2.tepper.cmu.edu/fmargot/coin/proj5.pdf
>
>  Regards
>
>
>
>  ------------------------------
> Date: Tue, 9 Oct 2012 20:50:04 +0300
> From: chtsolak at gmail.com
> To: dibarra21 at hotmail.com
> CC: cbc at list.coin-or.org
> Subject: Re: [Cbc] solving time in C++ >> time in Gams
>
> i have the latest version, 2.7.7....
>
> I solve it by using the default cbc solver, (i am not getting involved in
> the solver) with this way:
>
> *solver1.loadProblem(numcols, numrows, start, index, value, collb, colub,
> obj, rowlb, rowub);
> CbcModel model(solver1);
> CbcMain0(model);
> const char * argv2[]={"DAS","-solve","-quit"};   **
> CbcMain1(3,argv2,model);    *
>
> So, i do not think that it's ommiting the presolve step, am i wrong?
>
> Where can i find the latest version, and how can i load an mps file?
>
> Thank you
>
> On 9/10/2012 20:42, David Ibarra Gómez wrote:
>
>  Hi,
>
>  there are several things that can cause this:
>
>
>    - different solvers version,
>    - solving is a complex task: presolve (cuting planes, heuristics, ...)
>    and then branch and bound (cut). If you omit the first part or you do
>    not do exactly the same steps result could be different.
>
>
>  Did you try to solve using CBC CLI (stand alone executable) ?
>
>  Regards
>
>  ------------------------------
> Date: Tue, 9 Oct 2012 12:16:49 +0300
> From: chtsolak at gmail.com
> To: cbc at list.coin-or.org
> Subject: [Cbc] solving time in C++ >> time in Gams
>
> Hi all again,
>
> I have 1  question for you, if i solve it, i won't bother you again :-P
>
> I am using cbc in order to make an executable via MS visual studio which
> solves a model.
> In order to solve it, takes 60 mins
>
> I have made the same problem with GAMS and solved it in 30 secs, 120 times
> faster!!
>
> Is it because of an error in modeling or due to the different interface?
> (exe-GAMS)
>
> Why is there this enormous difference?
>
>
> Thank you in advance.*
> *
> *
>
> *
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>
>
>
>
>
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>


-- 
*Iain Dunning*
PhD Student <http://orc.scripts.mit.edu/people/student.php?name=idunning> / MIT
Operations Research Center <http://web.mit.edu/orc/www/>
www.iaindunning.com
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