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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 03/02/07 16:32:16 GAMS Rev 147 Copyright (C) 1987-2007 GAMS Development. All rights reserved Licensee: Franz Nelissen S070222/0001CN-WIN GAMS Software GmbH DC3459 --- Starting compilation --- trnsport.gms(69) 3 Mb --- Starting execution --- trnsport.gms(45) 4 Mb --- Generating LP model transport --- trnsport.gms(66) 4 Mb --- 6 rows 7 columns 19 non-zeroes --- Executing CPLEX GAMS/Cplex Feb 14, 2007 WIN.CP.CP 22.4 033.036.041.VIS For Cplex 10.1 Cplex 10.1.1, GAMS Link 33 Reading data... Starting Cplex... ...
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 15MB, if you have to send us larger file we recommend to use a free exchange file 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.