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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 22.5 - June 01, 2007

This is a Major release.

Acknowledgements

We would like to thank all of our users who have reported problems and made suggestions for improving this release. In particular, we thank Christian Gilow and Josef Kallrath.

GAMS System

  • New functions and features
    • Added functions system.gamsrelease and gamsrelease
    • Added function poly(x,a0,a1,a2,a3..) = sum(i=0 to n, ai*x^i)
    • Appendout (ao)=2 will redirect the listing file to stdout. This feature is not available when running under the IDE.

  • GAMS IDE:
    • Open in new window creates now a single new window when multiple files have been selected
    • Spelling menu entry added to Edit menu
    • Gdxviewer can write a single symbol and all symbols to an Excel file

  • GAMS Model library: New models
    • eps-Constraint Method for Multiobjective Optimization (epscm)
    • Kissing Number Problem using Variable Neighborhood Search (knp)
    • Termination routine to ensure solvers stay with resource limit (schulz)
    • How to test for a GAMS version (version1)

Solvers

  • AlphaECP: A new solver called GAMS/AlphaECP for mixed integer non-linear problems has been added to the GAMS solver portfolio. AlphaECP is an implementation of the Extended Cutting Plane method by Tapio Westerlund and Toni Lastusilta from Abo Akademi University, Finland. The GAMS/AlphaECP solver requires the presence of a licensed MIP solver only.

  • BARON: New libraries (version 7.8) with improved local search routines.

  • COIN-OR Solvers: New libraries for CoinCbc, CoinGlpk, and CoinIpOpt. The experimental MINLP solver CoinBonmin has been introduced for the GAMS Windows and Linux systems. Bonmin (Basic Open-source Nonlinear Mixed INteger programming) provides an implementation of an NLP-based branch-and-bound algorithm, an outer-approximation decomposition algorithm, an implementation of Quesada and Grossmann's branch-and-cut algorithm, and a hybrid outer-approximation based branch-and-cut algorithm.

  • CONOPT: New libraries (version 3.14r).

  • CONVERT:
    • Added option 'NLP2MCP' that reformulates a non-integer program as a mixed complementarity problem (MCP)
    • Added option 'AmplNLC' that converts a model into C code for evaluating objectives, constraints, and their derivatives.
    • Added option 'Jacobian' that creates a GDX file containing the basic model data (matrix, initial point, evaluation of constraints at initial point and bounds)
    • Added option 'LindoMPI' that creates an MPI file which is readable by Lindo.

  • CPLEX: New libraries (version 10.20).

  • LINDOGLOBAL: The Global Optimization Solver (GAMS solver name is LINDOGLOBAL) from Lindo Systems, Inc. has been added to the GAMS solver portfolio. LINDOGLOBAL finds proven optimal solutions to non-convex mixed integer non-linear problems. The LINDOGLOBAL solver requires a license for GAMS/CONOPT. The size of a model solved by LINDOGLOBAL is limited to 2,000 equations and 3,000 variables.

  • MOSEK: New libraries (version 4.0.0.60)

  • XPRESS: New libraries (version 17.10.12)

Solver/Platform availability - 22.5    June 1, 2007
  x86
MS Windows
x86_64
MS Windows
x86
Linux
x86_64
Linux
Sun Sparc
SOLARIS
Sun Intel
SOLARIS
HP 9000
HP-UX 111
DEC Alpha
Digital Unix 4.0
IBM RS-6000
AIX 4.3
Mac PowerPC
Darwin
ALPHAECP x x x x x x   x x x
BARON 7.8 x 32bit x 32bit         x  
BDMLP x x x x x x x x x x
COIN x 32bit x x           x
CONOPT 3 x x x x x x x x x x
CPLEX 10.2 x x x x x x 10.0 8.1 x  
DECIS x x x x x x x x x  
DICOPT x x x x x x x x x x
KNITRO 5.1 x 32bit x x           x
LINDOGLOBAL 4.1 x x x x x         x
LGO x x x x x x x x   x
MILES x x x x x x x x x x
MINOS x x x x x x x x x x
MOSEK 4 x x x x x   3.2     x
MPSGE x x x x x x x x x x
MSNLP x x x x x x x     x
NLPEC x x x x x x x x x x
OQNLP x 32bit x 32bit            
OSL V3 x 32bit x 32bit x x V2   x  
OSLSE x 32bit x 32bit x       x  
PATH x x x x x x x x x x
SBB x x x x x x x x x x
SNOPT x x x x x x x x x x
XA x 32bit x x x   x x x  
XPRESS 17.10 x 32bit x 32bit x   16.10   x  
1)GAMS distribution for HP 9000/HP-UX is 22.1.
2)GAMS distribution for SGI IRIX is 22.3.