[Clp] Clp Digest, Vol 109, Issue 7

[Miles Lubin]

Hi Wolfgang,

If you're reading from an MPS file, there shouldn't be any difference
at all between using the C interface, the C++ interface, or the CLI.
Does the CLI return the same objective value as the C interface?

I don't believe it's possible to access the presolved model by using
the C api, but you can disable presolve if you believe that this could
be an issue. In recent versions of Clp, you can do this by creating a
ClpSolve object, calling ClpSolve_setPresolveType, and then passing
the ClpSolve object to Clp_initialSolveWithOptions.

Best,
Miles

On Wed, Jul 30, 2014 at 1:44 AM, Wolfgang Hartmann
<cmat.wolfgang at gmail.com> wrote:
> Hi,
> I'm using the C Interface for Clp!!
>
> that means I'm calling (among others):
>   -  irc = Clp_readMps(model,ofil,1,0);
>   - one of the following four:
>     irc = Clp_dual(model,ifValuesPass);
>     irc = Clp_initialDualSolve(model);
>     irc = Clp_primal(model,ifValuesPass);
>     irc = Clp_initialPrimalSolve(model);
>
> For larger Problems, however, the Solutions I get are infeasible.
> With any of the methods above!
>
> I had a look at the C++ examples and thought maybe running something like
>    Presolved.Info.presolvedModel(model)
> would help getting some more reasonable result.
>
> However, I did not find something similar in the C Interface source code
> distributed with Clp.  Is it just me or is there anybody else of you who
> works
> with that C Interface? How do you call
>    Presolved.Info.presolvedModel(model)
> using the C Interface??
>
> Thanks,
> Wolfgang
>
>
> --
> Time is not Onedimensional!
> And even if it were - it would still be too difficult for me to handle.---
> Wolfgang M. Hartmann
>
>
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