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<div>Hi Pietro,</div>
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<div>thanks for your help. Do you know if there exists a good paper with explanations how these 2 heuristics work?</div>
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<div>Best, Ina</div>
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<div style="margin:0 0 10px 0;"><b>Gesendet:</b> Freitag, 29. März 2013 um 04:42 Uhr<br/>
<b>Von:</b> "Pietro Belotti" <pbelott@clemson.edu><br/>
<b>An:</b> Liffey1986@gmx.de<br/>
<b>Cc:</b> "Couenne mailing list" <couenne@list.coin-or.org><br/>
<b>Betreff:</b> Re: [Couenne] solution output / heuristics</div>
<div name="quoted-content">Hi Ina, > 1) Does this mean that Couenne found a new AND better solution to the > incumbent, or just a new solution that might not be better? It means that Couenne found a new and better solution. > 2) I solved some instances and the only heuristics that found solutions > are 'Init Rounding NLP' and 'Couenne Rounding NLP'. Does Couenne only > use these 2 heuristics? Yes, and actually they are the same heuristic, the "Init" version being something that is applied at the very beginning. Of course a solution can also be found after solving the LP relaxation (whose solution sometimes happens to be integer feasible), strong branching, etc. A feasibility pump heuristic is available in trunk and stable/0.4, but it is quite time consuming. You can enable it with the option feas_pump_heuristic yes in the couenne.opt option file. Regards, Pietro -- Pietro Belotti Dept. of Mathematical Sciences Clemson University email: pbelott@clemson.edu phone: 864-656-6765 web: <a href="http://myweb.clemson.edu/~pbelott" target="_blank">http://myweb.clemson.edu/~pbelott</a> On Tue, 26 Mar 2013, Liffey1986@gmx.de wrote: > Hi all, > > in the output Couenne gives information whenever a solution is found > (Integer solution of xxx found by xxx). > I have two questions about this: > > 1) Does this mean that Couenne found a new AND better solution to the > incumbent, or just a new solution that might not be better? > > 2) I solved some instances and the only heuristics that found solutions > are 'Init Rounding NLP' and 'Couenne Rounding NLP'. Does Couenne only > use these 2 heuristics? > > Best, Ina</div>
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