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<p><tt>> Matt,<br>
> <br>
> As far as I know this is a feature of cbc. There's a thread in the cbc<br>
> mailing list (`More problem with re-solving a model', 6 Apr 2009) that talks<br>
> about just this issue. The solution proposed there (dating back to 2008) is to<br>
> use the saveReferenceSolver() and resetToReferenceSolver() methods from<br>
> CbcModel.<br>
> <br>
> Hard to say why this developed as it did, except that it's clearly more<br>
> efficient in a single-solve use to leave the problem representation in whatever<br>
> state it's in at the conclusion of the solve.</tt><br>
<br>
<tt>It's easy to say why is this there: John Forrest wrote cbc, and that's</tt><br>
<tt>how it was in OSL. Now why it was this way in OSL...</tt><br>
<br>
<tt>Anyway, to achieve solver independence it should be OsiCbc's job to</tt><br>
<tt>hide this from the user: either</tt><br>
<tt>- save the lb/ub vector just before it calls cbc to optimize and restore </tt><br>
<tt> them after the call is done. (And make this in a fashion that every </tt><br>
<tt> result is still accessible.); or</tt><br>
<tt>- keep a cached copy of lb/ub, update its cached copy when necessary and</tt><br>
<tt> return those when the user queries.</tt><br>
<br>
<tt>--Laci</tt><br>
<tt><br>
> <br>
> Lou<br>
> <br>
> _______________________________________________<br>
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