Release Notes

Major releases contain substantial changes to the GAMS system. The License Check date is set to the release date of the major release.

Minor releases are mainly issued to provide bug fixes, performance improvements, and maintenance releases of solver libraries. Additionally, they can provide a few new features that do not change existing behavior. The License Check Date remains the same as for the prior major release. This means that any license file that worked with the prior major release will also work with this minor release.

Maintenance releases do not provide any new features. They are issued to provide bug fixes, performance improvements, and maintenance releases of solver libraries. The License Check Date remains the same as for the prior major release. This means that any license file that worked with the prior major release will also work with this maintenance release.

GAMS Distribution 21.6 - January 26, 2005

This is a Minor release.

Acknowledgments

We would like to thank all of the users, particularly Josef Kallrath, who have reported bugs or made suggestions in improving this release.

Solvers

  • BARON: New libraries are included. Several new features which are documented in the BARON solver manual.

  • CONVERT:
    • New model instance format CoinFML, Coin style XML model file.
    • LINGO format updated to include Version 9 features

  • COIN:
    • CoinGlpk: New COIN and GlpK 4.7 libraries.
    • CoinSbb: This is now called CoinCbc (Coin Branch & Cut). The name CoinSbb will remain for this and the next distribution.
    • Three new cuts classes: Clique, Flow Cover, Mixed Integer Rounding and all new libraries.

  • KNITRO: New libraries are included which address minor fixes.

  • XPRESS: New libraries are included which address minor fixes.

GAMS System

  • Model Library:
    • licememo: Generate your own license memorandum and solver matrix with this model.
    • deploy: Generate a minimal deployment GAMS system with necessary components only.

  • Testlib: 26 new quality assurance tests have been added to the suite.

  • Minor enhancements:
    • $onecho and $onput have new variants to specify verbatim or substitutions. The new names are: $onechoV, $onechoS, $onputV, $onputS.
    • Manipulation of system environment variables and prefixing of the search path:
       $SetEnv name value
      $DropEnv name
      $PrefixPath value

      %SysEnv.name%

      $if SetEnv name

  • fml2gms: converts a CoinFML style XML file into GAMS (courtesy of Leo Lopes, University of Arizona). An example showing how to convert from GAMS to CoinFML format and back to GAMS is shown below:
     > gamslib trnsport
    > echo coinfml > convert.opt
    > gams trnsport optfile=1 lp=convert
    > fml2gms coinfml.xml
    > gams fml2gms.gms

Documentation

  • Bruce McCarl User's Guide:
    • accessing the guide through the GAMS/IDE, will now launch the PDF file directly instead of through a web browser. This is due to possible incompatibility issues with Windows XP Service Pack 2 (securtiy settings). To launch via the web, users can go to File > Options and check the box "Launch docs using Explorer."