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Re[4]: [Help-glpk] proposal for gnu lp/mip low-level format
From: |
Andrew Makhorin |
Subject: |
Re[4]: [Help-glpk] proposal for gnu lp/mip low-level format |
Date: |
Thu, 29 Jul 2004 08:25:28 +0400 |
>> There was an idea to implement a "mathematically exact" version of the
>> simplex method which would perform all calculations in rational numbers
>
>I'm not suggesting that rationals be used internally.
>As you noted, multi-precision is too slow.
There is an exact lp solver, exlp, which is based on GNU MP library
and performs all computations in rational numbers:
http://members.jcom.home.ne.jp/masashi777/exlp.html
(There are more things in heaven and earth, Horatio, ... :+).
And it looks like the solution time is not so pessimistic even for
real-world models (I'm attaching exlp's benchmarks for netlib).
The solver's output is just fanatstic:
$ ./exlp boeing2.mps
variables: 162
rows: 166
iteration count(degenerate): 95(36)
iteration count(degenerate): 57(25)
optimal value: -6239290250177881164363943/19806093083700000000000
(-315.018728015)
size: 3/3
Andrew Makhorin
bench-steepest-edge.
Description: Binary data
bench-dual.
Description: Binary data
- [Help-glpk] proposal for gnu lp/mip low-level format, Andrew Makhorin, 2004/07/21
- Re: [Help-glpk] proposal for gnu lp/mip low-level format, Brady Hunsaker, 2004/07/22
- Re: [Help-glpk] proposal for gnu lp/mip low-level format, Michael Hennebry, 2004/07/22
- Re[2]: [Help-glpk] proposal for gnu lp/mip low-level format, Andrew Makhorin, 2004/07/23
- Re[2]: [Help-glpk] proposal for gnu lp/mip low-level format, Michael Hennebry, 2004/07/27
- Re[3]: [Help-glpk] proposal for gnu lp/mip low-level format, Andrew Makhorin, 2004/07/28
- Re[3]: [Help-glpk] proposal for gnu lp/mip low-level format, Michael Hennebry, 2004/07/29
- Re[5]: [Help-glpk] proposal for gnu lp/mip low-level format, Andrew Makhorin, 2004/07/30
- Re[5]: [Help-glpk] proposal for gnu lp/mip low-level format, Michael Hennebry, 2004/07/30
- Re[4]: [Help-glpk] proposal for gnu lp/mip low-level format,
Andrew Makhorin <=