I am releasing a new user tutorial that was developed as part of a soon to be released Users Guide. It addresses Optimization, equation solution, and non MPSGE oriented users and is on http://www.gams.com/mccarl/tutorial.pdf with a copy including examples on http://www.gams.com/mccarl/tutorial.zip. (The user guide will be appearing soon; if anyone knows tricks about how to take a 1000 page document with 6000 hyperlinks and make a pdf please let me know).
There was a problem with GAMSBAS and GAMSCHK due to a change in the dictionary file and the compiler. These have been repaired, the revised versions are on http://www.gams.com/update/ and will standardly be in future releases.
A server (PAVER) is now available that automates the task of performance analysis and visualization, and enables users to reproduce performance tests. It contains on-line tools for batch file creation and for performance analysis and visualization as well as model conversion. It is discussed at http://www.gamsworld.org/performance/paver/index.htm and used in the presentation on Global Optimization in GAMS at http://www.gams.com/presentations/present_cocos02.pdf.
The last several months have seen developments with regard to spreadsheet links in GAMS.
The GAMS to and from spreadsheet utilities XLDUMP, XLEXPORT and XLIMPORT developed by Tom Rutherford's group at the University of Colorado have been further updated.
GAMS has made a spreadsheet transfer program called GDXXRW
that allows
data to move back and forth between EXCEL and GAMS via GDX files. It
is limited to Windows platforms and is documented in
GDXUtils.pdf.
It has more capability than
the other mechanisms but is more technical in it's requirements.
Both utilities (Rutherford's Excel tools and GDXXRW) are standardly
available in current releases and updates can be downloaded at
http://www.gams.com/update/.
Erwin Kalvelagen has developed procedures that export to and import from EXCEL as explained in the document Interfacing GAMS with other applications at http://www.gams.com/interface/interface.html.
Tom Rutherford has just made according to a recent email XLS2GMS -- a wrapper for XLHTML (see http://chicago.sourceforge.net/xlhtml/). Which is a "no-frills translator for moving data from XLS files into GAMS. The virtue of the tool is that it should be portable across platforms (including Unix machines) and it does not require Excel." He further states "I've not written any documentation yet, as I'm not sure if it is going to be sufficiently functional to warrant the work. Could some of you GAMS programmers who use Excel files regularly give this a whirl and let me know whether it works with your data?" The program is downloadable from http://debreu.colorado.edu/xls2gms.zip.
This newsletter is not a product of GAMS Corporation although it is distributed with their cooperation.
October 21, 2002