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Here are several reasons why you may want some help:
Of course we cannot do all the modeling work for you (unless you hire us as a consultant) but we have lots of experience in using GAMS in both small and large, complex modeling situations in all kind of different application areas, ranging from economics to chemical engineering. Just talking to us for a few minutes may put you on the right track again.
In case you think GAMS or the solver fails, please provide us with as much relevant information as possible, such as:
Most of these information are included in the log file:
model_name.login your GAMS project directory. Alternatively you may just copy and paste the content of the process window into an e-mail.
gams trnsport.gms o=2) to redirect the screen output into a log-file.
Find below an example of a log file (
--- Job trnsport.gms Start 05/16/08 14:58:33 GAMS Rev 227 Copyright (C) 1987-2008 GAMS Development. All rights reserved Licensee: Franz Nelissen S080428/0001CN-WIN GAMS Software GmbH DC3459 --- Starting compilation --- trnsport.gms(69) 3 Mb --- Starting execution: elapsed 0:00:00.004 --- trnsport.gms(45) 4 Mb --- Generating LP model transport --- trnsport.gms(66) 4 Mb --- 6 rows 7 columns 19 non-zeroes --- Executing CPLEX: elapsed 0:00:00.009 ILOG CPLEX May 1, 2008 22.7.2 WIN 4792.4799 VIS x86/MS Windows Cplex 11.0.1, GAMS Link 34 Reading data... ...
Please send us that file.
If possible also attach a (zipped) copy of your model and all necessary data files, which will allow us to reproduce the problem. If there are include files or other data sources, please use the
dumpopt parameter to produce a single source file. In case there are confidential issues, you may send us a scalar version of your model, see: http://www.gams.com/docs/support/convert.htm for instructions abut that and the usage of the
Our e-mail system can handle attachments up to a size of 15MB. If you have to send us larger file we recommend to use a free exchange file service provider. We have made good experience with drop.io.
As a security measure to prevent potential viruses, our mail system does not allow users to receive executable files (such as files ending in .exe, bat, or cmd), even if they are sent in a zipped (.zip, .tar, .tgz, .taz, .z, .gz) format. Any message of this type sent to us will be bounced back you. Adding an underscore to the file attachment (e.g. file.zip_) may help.