[Coin-discuss] How to choose a MIP solver in GLPK OSI?

[Stefan Vigerske]

Hi,

> I have a MIP problem that GlpSol with "--intopt" solves in 0.2 seconds, 
> but won't solve at all without the option  (I let it run over the 
> weekend, it did not even find a feasible solution...)
> 
> Unfortunately, using GLPK OSI uses the old/original lpx_integer() 
> method, which is equivalent to running glpsol without parameters - and 
> hence useless for my problem.
> Is there a way (in OSI) to use lpx_intopt() instead of lpx_integer(), 
> other than rewriting OsiGlpkSolverInterface::branchAndBound() and 
> re-compiling OSI?

It is planned for the near future to check during the configure whether 
lpx_intopt is available and to use it in this case.

Best,
Stefan

> I found a discussion on coin-osi-devel from March 2006:
> http://list.coin-or.org/pipermail/coin-osi-devel/2006-March/000002.html
> Has anything changed since then? I really believe that it is important 
> that OSI has some (preferably simple-to-use) interface to 
> solver-specific options.
> 
> Note: In the discussion, they mention downcasting/direct call of the 
> GLPK function. Would it work also from FlopCpp? If so, could someone 
> show me how?
> 
> 
> Thanks a lot in advance.
> 
> 
> Regards,
> Michal Kaut
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> 


-- 
Stefan Vigerske
Humboldt University Berlin, Numerical Mathematics
http://www.math.hu-berlin.de/~stefan