[Couenne] Couenne and Cplex

[Pietro Belotti]

Hi Giacomo,

I don't know if that is a problem with Couenne generating a numerically 
unstable LP. CPX_ERR_NO_SOLN (code 1217) follows an attempt to read a 
solution before the problem is actually solved. I haven't looked at the 
Cplex interface used by Couenne for a while, but the LP solver interfaces 
in Couenne are all transparent to the actual solver (they are templated 
on Osi???SolverInterface classes).

I will try to address this issue as soon as I can, but in the meantime can 
you check whether the solve() methods in 
Couenne/src/problem/CouenneSolverInterface.cpp are actually called?

Thanks,
Pietro

--
Pietro Belotti
Dept. of Mathematical Sciences
Clemson University
email: pbelott at clemson.edu
phone: 864-656-6765
web:   myweb.clemson.edu/~pbelott

On Tue, 16 Nov 2010, Giacomo Nannicini wrote:

> Hi,
> if I set the option:
>
> couenne.lp_solver cplex
>
> and try to use Cplex as LP solver, I get a huge amount of error messages:
>
> CPX0000  CPLEX Error  1217: No solution exists.
>
> I didn't look into the problem, but maybe somebody knows what is the 
> cause of this problem and save me some time? Is this just a 
> visualization issue, i.e. the LPs are actually correctly solved and 
> simply turning off the output on screen is the right thing to do?
>
> Thanks
>
> Giacomo
>
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