[Cbc] cbc solver

[Ted Ralphs]

If you post the MPS file, I'm sure someone will be able to help.

Ted

On Wed, Mar 8, 2017 at 7:53 PM, Liu, Lu <Lu.Liu at fisglobal.com> wrote:

> Hi,
>
>
>
> I created a MPS file for my problem and I have tried CBC solver via the
> command line and also CPLEX via an online solver. CBC returned “ problem is
> unbounded” error, but CPLEX is able to give me a solution and the solution
> obeys the constraints. I wonder if this is a limitation of CBC. In
> addition, in the CBC command window, I also found that it says:
>
>
>
> Problem SOLVER_TEST has 26 rows, 32 columns and 118 elements
>
>
>
> but in my problem, I only have 25 columns, I find this suspicious. Could
> it be my MPS file formatting problem which leads the solver to think there
> are 32 variables? When I tweak the objective function and tried to make it
> bound, I got a solution like below:
>
> X1
>
> X2
>
> X2
>
> X3
>
> X3
>
> …
>
> X8
>
> X8
>
> X9
>
> X10
>
>
>
> Clearly it seems to treat some of my variables as duplicates, can someone
> help? Thanks!
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-- 
Dr. Ted Ralphs
Visiting Researcher, Zuse Institute Berlin
Professor, Lehigh University
(610) 628-1280
ted 'at' lehigh 'dot' edu
coral.ie.lehigh.edu/~ted
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