[Osi] issue in OsiCbc - corrupting bounds

[Matthew Galati]

I am trying to make my code independent of solver. That is, I am coding using base OSI so that I don't need different codes for CBC and CPX. Using CbcModel defeats the purpose.

I guess OSI solver independence is not really possible when doing MIP stuff? 

> -----Original Message-----
> From: osi-bounces at list.coin-or.org [mailto:osi-bounces at list.coin-or.org]
> On Behalf Of Lou Hafer
> Sent: Monday, August 09, 2010 12:09 PM
> To: osi at list.coin-or.org
> Subject: Re: [Osi] issue in OsiCbc - corrupting bounds
> 
> Matt,
> 
> 	As far as I know this is a feature of cbc.  There's a thread in the cbc
> mailing list (`More problem with re-solving a model', 6 Apr 2009) that talks
> about just this issue.  The solution proposed there (dating back to 2008) is to
> use the saveReferenceSolver() and resetToReferenceSolver() methods from
> CbcModel.
> 
> 	Hard to say why this developed as it did, except that it's clearly more
> efficient in a single-solve use to leave the problem representation in
> whatever state it's in at the conclusion of the solve.
> 
> 						Lou
> 
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