Re: [Help-glpk] glpk 4.49 release information

[Meketon, Marc]

Thank you for the link.  I had known about that work, but it's only for an 
academic license.  I did request it once (I am also an adjunct professor at 
Villanova University) to look at it, but the academic license holds me back 
from using it as I would have liked to.


-----Original Message-----
From: Robbie Morrison [mailto:address@hidden
Sent: Thursday, April 18, 2013 4:42 AM
To: GLPK help
Cc: Meketon, Marc
Subject: Re: [Help-glpk] glpk 4.49 release information


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]



This e-mail and any attachments may be confidential or legally privileged. If 
you received this message in error or are not the intended recipient, you 
should destroy the e-mail message and any attachments or copies, and you are 
prohibited from retaining, distributing, disclosing or using any information 
contained herein.  Please inform us of the erroneous delivery by return e-mail. 
Thank you for your cooperation.