Search found 32 matches

by Lutz
2 years ago
Forum: Modeling
Topic: Stochastic Programming: pre-sampled discrete random VECTOR
Replies: 1
Views: 1013

Re: Stochastic Programming: pre-sampled discrete random VECTOR

Hi,

You need to use the emp keyword "jrandvar". Here is an example where this is used:

https://www.gams.com/latest/emplib_ml/l ... joint.html

More general information can be found here:

https://www.gams.com/24.9/docs/UG_EMP_SP.html

I hope that helps,
Lutz
by Lutz
2 years ago
Forum: Modeling
Topic: Daily subsets of annual data
Replies: 2
Views: 1182

Re: Daily subsets of annual data

Hi, One way to do this, is using the "mod" function together with the "ord" operator: set t hours of a year /t1*t8760/; * Init everything to 5 parameter P_el(t) electricity price /#t 5/; * Set peak hours to 10 P_el(t)$(mod(ord(t),24)>=7 and mod(ord(t),24)<=18 ) = 10; If you need more structure about...
by Lutz
2 years ago
Forum: Solvers
Topic: GAMS vs Matlab vs Modelica
Replies: 2
Views: 1721

Re: GAMS vs Matlab vs Modelica

Hi, here are two simple power models (but that are probably the ones you found already): https://www.gams.com/latest/gamslib_ml/libhtml/gamslib_magic.html https://www.gams.com/latest/gamslib_ml/libhtml/gamslib_turkpow.html There is also a (very simple) CHP model packed into an Excel application: htt...
by Lutz
2 years ago
Forum: Tools
Topic: How to enable solver output when using Grid GAMS
Replies: 2
Views: 1609

Re: How to enable solver output when using Grid GAMS

Hi, When you use Grid, the Solver log is suppressed by default, since it would be all mixed if you have many solves in parallel. However, you can instruct GAMS to write the log to a file, which would also cause the solver log to be written to a file (better: to separate files for each solve). To do ...
by Lutz
3 years ago
Forum: Syntax
Topic: LXI File
Replies: 2
Views: 1211

Re: LXI File

Hi Javaelx, The lxi file contains information to navigate through the lst file when using the GAMSIDE. So by default it is created only, when you start your model from the GAMSIDE. However, you can mimic this behavior on the command line, when you set the command line option "IDE=1", so gams mymodel...
by Lutz
3 years ago
Forum: Modeling
Topic: Projected
Replies: 1
Views: 1344

Re: Projected

Renger, This is about the solution reading of GAMS. If the solver return a level of a variable, which is close to one of its bound (where "close to" can be controlled by the mentioned model attribute tolProj, the default is 1e-8), GAMS "projects" this value to the bound, so reports the bound value i...
by Lutz
3 years ago
Forum: Syntax
Topic: GAMS log file in Linux
Replies: 6
Views: 2262

Re: GAMS log file in Linux

mldizd wrote:Hello,
Please let me know How I can post my question in this forum. H don't find any icon in this regard.
Thanks in advance
Just select a topic, e.g. "Syntax" (https://forum.gamsworld.org/viewforum.php?f=2) and click the "New Topic" button on the top.

Lutz
by Lutz
3 years ago
Forum: Syntax
Topic: GAMS log file in Linux
Replies: 6
Views: 2262

Re: GAMS log file in Linux

Hi, You did not mention the GAMS version you are using, so I was assuming that you use the recent one. However, it seems that your version is rather old. LogOption=4 was introduced with GAMS 24.1 in 2013 (https://www.gams.com/latest/docs/releasenotes/24.1.html). Older versions than that do not accep...
by Lutz
3 years ago
Forum: Syntax
Topic: GAMS log file in Linux
Replies: 6
Views: 2262

Re: GAMS log file in Linux

Hi,

You have to set the command line option "LogOption" (or short "lo") to either 2 or 4. Here you can find more details about that option:

https://www.gams.com/latest/docs/usergu ... SLogOption

Best regards,
Lutz
by Lutz
3 years ago
Forum: Solvers
Topic: Problem with the Model status with Antigone solver
Replies: 9
Views: 2749

Re: Problem with the Model status with Antigone solver

As I understand, there is no other possible model status for GAMS after a succesful solve for an NLP that a local optimum. The GAMS manual explicitly mentions this in http://www.gams.com/latest/docs/userguides/mccarl/modelstat_tmodstat.htm BTW: Thanks for mentioning this! This is probably a note fr...