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Re: [Help-glpk] GLPK and MIPLIB 2003 manna81.mps
From: |
glpk xypron |
Subject: |
Re: [Help-glpk] GLPK and MIPLIB 2003 manna81.mps |
Date: |
Thu, 29 May 2008 08:25:30 +0200 |
Hello Jen-Min,
the problem file can be found at
http://miplib.zib.de/miplib2003/manna81.php
The optimum solution is described in
http://www.dei.unipd.it/~fisch/papers/lexGomory_cuts.pdf
as
LP opt = -13297
MILP opt = -13164.
-13164 is the first integer solution found by GLPK (after 2 minutes on a rather
slow Linux server) with a gap of 1 %.
This matches a report concerning the Dash optimizer
http://www.ima.umn.edu/2004-2005/W7.25-29.05/activities/Perregaard-Michael/cbranch.ppt
manna81: solved on root with no branching.
Could You, please, identify which is the termination criterion for COIN_OR, e.g
does it simply stop if the gap is less then 1 %? Glpsol will only stop at a
much smaller gap if You do not use the command line parameter --mipgap.
Which was the optimum found by COIN_OR?
Do You get the same result on Windows: MILP opt = -13164 for gap = 1 %?
Best regards
Xypron
-------- Original-Nachricht --------
> Datum: Wed, 28 May 2008 06:45:57 -0700
> Von: "Cheng,Jen-Min" <address@hidden>
> An: address@hidden
> Betreff: [Help-glpk] GLPK and MIPLIB 2003 manna81.mps
>
> I generated glpsol.exe 4.2.8 using Microsoft Visual Studio 2005. It did
> not stop after over 10 hours when manna81.mps of MIPLIB 2003 was being
> solved. However COIN_OR could solve manna81.mps in less than 10
> seconds.
>
> Will any please tell me what happened. Thanks.
>
>
>
>
> _______________________________________________
> Help-glpk mailing list
> address@hidden
> http://lists.gnu.org/mailman/listinfo/help-glpk
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