[Cbc] CBC Multiple Optimal Solutions

[Enio Gjerga]

Hi Haroldo,

Thank you very much for your feedbacks, I have truly appreciated.

I have tried to run my command on a simple toy example that I have prepared
and have tested the commands that you have suggested for obtaining the
multiple solutions of my problem. However, unfortunately it seemed like
that didn't work and I think I might be writing the commands wrong somehow.
I have tried to solve the problem with cplex and on that case I indeed am
able to obtain the multiple solutions that I wanted.

I am attaching a gdrive folder where I have the problem and the solutions
that I get with cplex and cbc:
https://drive.google.com/drive/folders/1GEvrNs-ScLr6NhbvsCnR6u8p0WAK1j7F?usp=sharing.
The testFile.lp contains the ILP problem, the command files contain the
cplex and cbc commands that I am using to solve that specific problem, the
cbc_execution contains the execution flow while optimizing the problem with
cbc solver while the cplex_results.txt + 2.sol, 3.sol and best.sol contain
the solutions that I obtain from cbc. Unfortunately it sems that the .sol
files are all identical and they don't contain the multiple solutions and
they contain only 1 of the 2 feasible solutions for this problem.

Please, is there something wrong on the way I am writing the cbc command
for solving? Are there any equivalent commands that are typically used for
the cplex (on the cplexCommand.txt files) that can also be used on the cbc?

I apologize for the late reply and for the long email. Any is always very
much appreciated:))

Cheers,
Enio

On Thu, 18 Jul 2019 at 14:07, Haroldo Gambini Santos <
haroldo.santos at gmail.com> wrote:

> Hi,
>
> If you like Python the Python-MIP interface for CBC provides easy access
> to the solution pool.
>
> https://github.com/coin-or/python-mip
>
> In the command line,
>
>   cbc air04.mps.gz -timem=elapsed -seconds 100 -maxSaved=200 -solve
> -solution best.sol
> -nextbest 2.sol -nextbest 3.sol
>
> Cheers
>
> --
> =============================================================
> Haroldo Gambini Santos
> Computing Department
> Universidade Federal de Ouro Preto - UFOP
> email: haroldo at ufop.edu.br
>         Haroldo.GambiniSantos at cs.kuleuven.be
> home/research page: www.decom.ufop.br/haroldo
>
>
> It has long been an axiom of mine that the little things are infinitely
> the most important.
> -- Sir Arthur Conan Doyle, "A Case of Identity"
>
> On Thu, 18 Jul 2019, Enio Gjerga wrote:
>
> > Hello,
> > I am Enio Gjerga, a PhD candidate working in RWTH Aachen and Heidelberg
> University
> > and my research focus consists on logic modelling of cell signalling
> networks. For
> > that I often rely on integer linear formulations for training my
> networks to the data
> > and I am particularly interested in cbc as a free MIP solver alternative.
> >
> > Please, is it possible for directly obtaining multiple solutions from
> the cbc solver?
> > If yes, is there any command I could use in the interactive mode of cbc
> for such a
> > purpose? I am very interested in my problems to explore as many
> alternative solutions
> > as possible.
> >
> > Looking forward for your kind reply and any help would be much
> appreciated.
> >
> > Best regards,
> > Enio Gjerga
> >
> > --
> > Enio GJERGA
> > PhD student
> > JRC-COMBINE RWTH Aachen
> > Tel : +4917685132057
> >
> [uc?export=download&id=0B6mjZ0BJeekOeUgyQmpTQXYwWjg&revid=0B6mjZ0BJeekORUxnZ1VVS1ZjY
> > 25UTUc2VUU1dDA4N0lLUlM0PQ]
> >
> >
>


-- 
Enio GJERGA
PhD student
JRC-COMBINE RWTH Aachen
Tel : +4917685132057
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