http://support.gams-software.com/ 2010-03-10T08:09:13-05:00 http://support.gams-software.com/ http://support.gams-software.com/lib/images/favicon.ico text/html 2010-03-09T07:36:02-05:00 support http://support.gams-software.com/doku.php?id=solver:using_lazy_constraints_or_user_cuts&rev=1268138162&do=diff GAMS/CPLEX does currently not support lazy constraint or user cuts. We have not seen convincing examples where these Cplex features make a significant difference in performance. We understand that this might be a chicken and egg problem, therefore we introduced some time ago a way to experiment with these Cplex features. This is not for production models but to see if these features improve performance for your model. text/html 2010-03-09T07:24:38-05:00 support http://support.gams-software.com/doku.php?id=solver:solver&rev=1268137478&do=diff General * How can I hook my own solver to GAMS? * Solver ignores the iterlim/reslim settings in my model * How do I automatically re-submit a model, which failed due to a solver license error? * How much Memory (RAM) does my GAMS Run require? * Model is unbounded / Model has an unbounded ray / Model Status 3 unbounded * Changing the default Solver * Intercepting a Solver Call * The Solver Option File * How do I interrupt a solver? * Solver option file not found (wrong file e… text/html 2010-03-08T06:40:41-05:00 support http://support.gams-software.com/doku.php?id=solver:cplex_error_32201&rev=1268048441&do=diff This error should not occur, if you have purchased a license for GAMS/CPLEX. If you are using a GAMS/CPLEX-Link it is mandatory that the ILOG license manager is also installed and running properly. You also need to set an environment variable ILOG_LICENSE_FILE to point to the ILOG license file access.ilm. text/html 2010-03-04T23:41:19-05:00 support http://support.gams-software.com/doku.php?id=start&rev=1267764079&do=diff “I get an error when I try to use GAMS. Do you have a fix for that? Best, ...” This wiki contains some material collected from various support activities. It mainly serves as an internal database for our support staff. We have decided to make it visible to the public, but keep in mind that this Wiki is under permanent construction, only limited editing has been done, and the structure and the contents may change at any time without notice. text/html 2010-02-23T06:36:06-05:00 support http://support.gams-software.com/doku.php?id=solver:the_solver_option_file&rev=1266924966&do=diff If you’ve not used an option file before, create a new file of that name and save it in the same directory as your GAMS source file. If you want the options to appear in your GAMS source code, you can use the following code fragment as an example (with an option file for baron as example): text/html 2010-02-19T04:22:00-05:00 support http://support.gams-software.com/doku.php?id=interfaces:send_model_status_to_a_gdx_file&rev=1266571320&do=diff Q: I'm using GDX to read model results. I export the results of my models using the following command when I launch the model: gams model.gms gdx = out.gdx. All the information is there, except information on the status of the model. Is there any option to export the model status (normal completion, infeasibilities, etc.) to the GDX file once the model is completed? text/html 2010-02-11T03:53:06-05:00 gams http://support.gams-software.com/doku.php?id=gams:linearize_a_non-linear_function&rev=1265878386&do=diff Find below some approaches to linearize the cubic function y =e= x*sqr(x) - 7*sqr(x) + 14*x - 8 $offsymxref offsymlist option limrow = 0, limcol = 0, solprint = off ; variable y,x ; equations eq ; eq.. y =e= x*sqr(x) - 7*sqr(x) + 14*x - 8 ; x.lo = 1 ; x.up = 10.5 ; model cubic /all/ ; solve cubic using nlp minimizing y ; display y.l, x.l ; text/html 2010-01-29T00:02:53-05:00 support http://support.gams-software.com/doku.php?id=gams:no_space_left_on_device&rev=1264741373&do=diff the full error message is: --- Reading solution for model complexStoch *** Unexpected EInOutError *** Msg=I/O Error. IoResult = 28. C OS errno = 28: 'No space left on device'. *** Please report to support@gams.com Exit code = 8 This error indicates you are either text/html 2010-01-27T23:58:15-05:00 support http://support.gams-software.com/doku.php?id=solver:supported_sub_solvers&rev=1264654695&do=diff In order to use GAMS/BARON, users will need to have a GAMS/BARON license as well as a licensed GAMS linear programming (LP) solver. A licensed GAMS nonlinear programming (NLP) solver is optional and usually expedites convergence. By default, GAMS/BARON will attempt to use CPLEX as the LP solver and MINOS as the NLP solver. If the user does not have licenses for these solvers, then the user must use the options LPSol and NLPSol to specify another LP or NLP solver.