Re: [Help-glpk] glpk 4.49 release information

[Robbie Morrison]

Hello Marc, all

------------------------------------------------------------
To:          "Meketon, Marc" <address@hidden>
Subject:      Re: [Help-glpk] glpk 4.49 release information
Message-ID:  <address@hidden>
From:         Andrew Makhorin <address@hidden>
Date:         Wed, 17 Apr 2013 01:32:21 +0400
------------------------------------------------------------

[snip]

> I am really glad that there is now a high-
> performance open-source solver that uses the
> relaxation method that others would also use and
> over time improve.
>
> Below here some benchmarks for a subset of
> Klingman's standard mincost flow instances
> (glp_netgen / glp_netgen_prob):

[snip : results table]

The University of Pisa Computer Science Department
have also reimplemented the original RELAX-IV
Fortran code, but into C++ instead.  They offer
their version with warning that the algorithm may
fail to converge.  The full text is:

 "RelaxIV is our C++ re-implementation of the
  Relaxation algorithm by D. Bertsekas, based on
  his original Fortran code. The code seems to
  work fairly well as a general-purpose MCF
  solver, and it is apparently capable of dealing
  with problems with nonintegral costs and/or
  capacities, although you have to be warned that
  Relaxation algorithms may in theory fail to
  converge with nonintegral data."

  http://www.di.unipi.it/di/groups/optimize/Software/MCF.html#RelaxIV

This information may be of interest to those using
the new 'glp_mincost_relax4' call.

Robbie
---
Robbie Morrison
PhD student -- policy-oriented energy system simulation
Technical University of Berlin (TU-Berlin), Germany
University email (redirected) : address@hidden
Webmail (preferred)           : address@hidden
[from Webmail client]