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<div>Hi John,</div>
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<div>The infeasibility is minimal – in the 1e-6 range. Your explanation makes sense; I'll just modify our CBC solver plugin to check+suppress the "**" prefix. </div>
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<div>As to why it doesn't happen that frequently, I haven't a clue…</div>
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<div>Jean-Paul</div>
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<span style="font-weight:bold">From: </span>John Forrest <<a href="mailto:john.forrest@fastercoin.com">john.forrest@fastercoin.com</a>><br>
<span style="font-weight:bold">Date: </span>Wed, 4 Apr 2012 08:56:00 +0100<br>
<span style="font-weight:bold">To: </span><<a href="mailto:cbc@list.coin-or.org">cbc@list.coin-or.org</a>><br>
<span style="font-weight:bold">Subject: </span>[EXTERNAL] Re: [Cbc] Question about "**" prefix in CBC solution file lines<br>
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<div bgcolor="#FFFFFF" text="#000000">Jean-Paul,<br>
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How infeasible?<br>
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The most likely explanation is that when scaled the problem was feasible within tolerance, but when the solution was unscaled it violated a tolerance. Clp would have reported that as optimal but with a secondary status flag set. OsiSolverInterface would drop
that information. Why this happens so rarely is odder.<br>
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John<br>
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On 03/04/12 04:40, Watson, Jean-paul wrote:
<blockquote cite="mid:CB9FCD32.23CD7%25jwatson@sandia.gov" type="cite">
<div>I just encountered our first Coopr user that has generated models such that the resulting CBC solution files contain rows for variable lines that are prefixed by "**". </div>
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<div>When I look at the code (CBCGenSolution.cpp), it is obvious that the "**" indicate – in the case of variables – that the bounds have been violated for this particular variable.</div>
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<div>This makes sense for a brief moment, until I realize that CBC is reporting the solution is optimal. Solutions can of course violate strict bounds when tolerances are considered, but I would assume I would see this behavior on any of the numerous other
models we have solved with CBC. </div>
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<div>Can anyone shed some light on this condition, and how the resulting solution should be interpreted? </div>
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<div>Thanks,</div>
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<div>Jean-Paul </div>
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