Just my 2-cents, but dropping to Cbc instead of supporting what is needed at OsiCbc defeats the purpose of OSI. OsiXxx should at least support LP and MILP solvers. <br><br>If the long term plan is really to just support LP solvers, than let's call it OSILP or something more appropriate.<br>
<br>Matt<br><br><br><br><div class="gmail_quote">On Tue, Jun 28, 2011 at 5:46 PM, Stefan Vigerske <span dir="ltr"><<a href="mailto:stefan@math.hu-berlin.de">stefan@math.hu-berlin.de</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hi,<br>
<br>
I agree with Lou.<br>
If you still want to use Cbc via Osi, then you can get to the CbcModel<br>
via OsiCbc::getModelPtr() and call the status methods from there.<br>
You can then call isNodeLimitReached(), isSecondsLimitReached(), and get<br>
the dual bound via getBestPossibleObjValue().<br>
Comparing the latter with getObjValue() should be most reliable for<br>
seeing whether Cbc finished with a proven optimal solution or how far it<br>
may still be away.<br>
<font color="#888888"><br>
Stefan<br>
</font><div><div></div><div class="h5"><br>
> Troy,<br>
><br>
>> Using the OSI interface to CBC,<br>
><br>
> This is your mistake :-) Seriously, Osi is just not set up to<br>
> provide the kind of control necessary for a MIP solver. If you want to<br>
> do anything more than run the solver to completion, you're better off to<br>
> use Cbc directly.<br>
><br>
> There are a few folks out there who are more fond of OsiCbc. One of<br>
> them may be able to offer more helpful advice.<br>
><br>
> Lou<br>
><br>
> if I call setMaximumSeconds and<br>
>> branchAndBound() terminates due to that limit, how do I distinguish<br>
>> between it finishing with a feasible (but possibly suboptimal)<br>
>> solution and finishing with an infeasible solution? I see methods<br>
>> like isProvenOptimal and isProvenPrimalInfeasible, but nothing like<br>
>> isFeasible.<br>
>><br>
>> I could loop over all of the integer variables and check if they are<br>
>> within tolerance of integer values, but it seems that there should be<br>
>> a method that does that (and does not risk me using the wrong<br>
>> tolerance or getting a different rounding error).<br>
>><br>
>> Is there something I am missing?<br>
>><br>
>> Troy<br>
>><br>
>><br>
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