[Coin-discuss] New release of LPFML: An XML schema for LP/MIP

[Leo Lopes]

This is a message announcing a release of a standards proposal for an XML schema for LP/MIP. We apologize if you receive multiple copies. Comments, suggestions, additions, and bug reports are always welcome.

There are numerous algebraic modeling languages for generating instances of
optimization problems, and even more numerous solvers for applying
optimization methods to problem instances.  These proliferating tools
achieve less than their potential, however, because each solver works with
only some languages, while each language supports only some solvers.

Modeler-solver compatibility could be greatly enhanced by adoption of a
standard problem instance representation.  As a step in this direction, we
are proposing LPFML, XML-based general representation for linear and
mixed-integer programming instances.  Our proposal incorporates a W3C XML
schema against which instances can be validated, together with a library of
open-source C++ classes that facilitate the use of LPFML for exchanging
information between modeling languages and solvers.

As examples of what can be done with LPFML, we provide the C++ classes that
allow LINDO and any of the OSI solvers (CLP, dylp, GLPK, and VOL, which are
open-source, plus CPLEX, OSL, SOPLEX, and XPRESS-MP) to read problem
instances and output solutions in LPFML format.  We also provide software
that allows LP or MIP models and data specified by means of the AMPL
modeling language to be translated to LPFML for solution.

The LPFML home page, http://gsbkip.uchicago.edu/fml/fml.html, provides links
to the LPFML schema, the interface library (source code, binaries, and
documentation), license information, several test problems, a bug submission
database, and a paper describing our approach in detail.

Bug reports, contributions to the library, and suggestions for revision or
extension are welcome, both directly to the authors and through the web
site.

Bob Fourer (4er at iems.northwestern.edu),
Leo Lopes (leo at sie.arizona.edu),
Kipp Martin (kmartin at gsb.uchicago.edu)


LPFML home page <http://gsbkip.uchicago.edu/fml/fml.html>
LPFML website response system <http://senna.sie.arizona.edu/fmlzilla/>

OSI <http://www-124.ibm.com/developerworks/opensource/coin/faqs.html#OSI>
LINDO <http://www.lindo.com>
AMPL <http://www.ampl.com>

-- 
========================================================================
Leonardo B. Lopes                                    leo at sie.arizona.edu 
Visiting Assistant Professor                               (520)626-1780
SIE - University of Arizona  http://www.sie.arizona.edu/faculty/leolopes