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Re: [Help-glpk] Infinite cycles
From: |
Heinrich Schuchardt |
Subject: |
Re: [Help-glpk] Infinite cycles |
Date: |
Wed, 11 Jan 2017 20:26:11 +0100 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.5.1 |
Hello Andrew,
The dual simplex method, techniques for a fast and stable implementation
/ Achim Koberstein
Paderborn, Univ., Diss., 2005
Dissertation (PhD)
describes on page 89 the possibility of numerical cycling due to the
Harris test:
http://digital.ub.uni-paderborn.de/hs/content/pageview/1508326
Wouldn't it be safer to change the default ratio test to --norelax.
See
https://pdfs.semanticscholar.org/2472/518346d657b8126d8ebe8657e2626dff5ef9.pdf
for ideas how to avoid cycling.
Best regards
Heinrich
On 01/11/2017 08:06 PM, Mathieu Dutour wrote:
> Thanks a lot!
>
> Mathieu
>
> On 11 January 2017 at 19:52, Heinrich Schuchardt <address@hidden
> <mailto:address@hidden>> wrote:
>
> glpsol -m GLP_buggy.mod --norelax
> runs fine.
>
> glpsol -m GLP_buggy.mod
> loops for ever.
>
> I tested with the GLPK 4.61 prerelease.
>
> Best regards
>
> Heinrich Schuchardt
>
> On 01/11/2017 12:14 PM, Mathieu Dutour wrote:
> > Dear all,
> >
> > I obtained some infinite cycles when running the
> > glpsol standalone solver on some instances.
> > See two files in attachment.
> >
> > I had the instances of this phenomenon with
> > version 4.57 which disappeared with version 4.60.
> >
> > Is there a way to avoid this phenomenon? I mean
> > it is fully acceptable to me to have GLPK report
> > that he cannot solve an instance due to numerical
> > instability. What is not acceptable is the infinite
> > cycles.
> >
> > Thanks in advance for any help.
> > Sincerely,
> >
> > Mathieu
> >
> >
> > _______________________________________________
> > Help-glpk mailing list
> > address@hidden <mailto:address@hidden>
> > https://lists.gnu.org/mailman/listinfo/help-glpk
> <https://lists.gnu.org/mailman/listinfo/help-glpk>
> >
>
>
- [Help-glpk] Infinite cycles, Mathieu Dutour, 2017/01/11
- Re: [Help-glpk] Infinite cycles, Heinrich Schuchardt, 2017/01/11
- Re: [Help-glpk] Infinite cycles, Andrew Makhorin, 2017/01/11
- Re: [Help-glpk] Infinite cycles, Mathieu Dutour, 2017/01/12
- Re: [Help-glpk] Infinite cycles, Mathieu Dutour, 2017/01/16
- [Help-glpk] Fwd: Re: Infinite cycles, Heinrich Schuchardt, 2017/01/16
- Re: [Help-glpk] Fwd: Re: Infinite cycles, Andrew Makhorin, 2017/01/16
- Re: [Help-glpk] Fwd: Re: Infinite cycles, Heinrich Schuchardt, 2017/01/16
- Re: [Help-glpk] Fwd: Re: Infinite cycles, Mathieu Dutour, 2017/01/17
- Re: [Help-glpk] Fwd: Re: Infinite cycles, Andrew Makhorin, 2017/01/17
- Re: [Help-glpk] Fwd: Re: Infinite cycles, Mathieu Dutour, 2017/01/17