[Osi] Is there a way to deactivate solver output?

Ted Ralphs ted at lehigh.edu
Sat Apr 24 14:23:12 EDT 2010

The branchandbound() method in OsiClp is a very basic branch and bound
implementation that should not really be used in practice. The
messages that are output there do not come through the message handler
and so you can't turn them off. If you really want to solve an integer
program, you should use Cbc directly. If you use OsiCbc, I think
things will work as you expect, although OsiCbc may have its own
quirks. I realize this is a bit confusing and it is in my TODO list to
look at these two Osi's and try to fix them up so they behave a little
more consistently. Perhaps there should really just be one Osi class
that calls both Clp and Cbc, depending on whether the problem is an LP
or an MILP. If you could file tickets on whatever we can't get
resolved quickly, that would be helpful.



On Sat, Apr 24, 2010 at 1:56 PM, Christophe-Marie Duquesne
<chm.duquesne at gmail.com> wrote:
> I guess this is because I solve a MIP problem, so I need some
> variables to be integers in the end. So I call:
>    osi->initialSolve();
> and then:
>    osi->branchAndBound();
> I guess the branch and bound part implies some Cbc call...
> --
> Christophe-Marie Duquesne
> 06 84 14 26 82 - mobile
> 04 76 57 48 06 - g-scop
> 04 97 23 27 33 - amadeus

Dr. Ted Ralphs
Associate Professor, Lehigh University
(610) 628-1280
ted 'at' lehigh 'dot' edu

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