Search found 57 matches

by bussieck
15 hours ago
Forum: Syntax
Topic: LOOP Problem
Replies: 3
Views: 57

Re: LOOP Problem

You are probably using an old version of GAMS. Singleton sets where introduced in 24.6 (7/2014). You probably should update your GAMS system.

-Michael
by bussieck
4 days ago
Forum: Archive Google Group
Topic: gams/cplex option file
Replies: 7
Views: 273

Re: gams/cplex option file

Uhhh, and I forgot the obvious, create a 'cplex.opt' not a model2.opt as clearly instructed in https://www.gams.com/latest/docs/UG_Sol ... PTION_FILE:

$onecho > cplex.opt
threads=0
$offecho

-Michael
by bussieck
4 days ago
Forum: Archive Google Group
Topic: gams/cplex option file
Replies: 7
Views: 273

Re: gams/cplex option file

Hi, just drop the ';' from the lines in the cplex.opt: $onecho > model2.opt threads=0 $offecho The ';' is important to separate GAMS language statements (see https://www.gams.com/latest/docs/UG_GAMSPrograms.html) The $xxx are dollar control options (https://www.gams.com/latest/docs/UG_DollarControlO...
by bussieck
2 weeks ago
Forum: API
Topic: Excel2Gams VBA problem
Replies: 2
Views: 76

Re: Excel2Gams VBA problem

David, We have a number of VBA (Excel) examples in datalib (e.g. https://www.gams.com/latest/datalib_ml/libhtml/datalib_Portfolio.html ) that use the following way to synchronously call GAMS: command = "gams " & fln result = CreateProcess(vbNullString, command, 0, 0, 0, NORMAL_PRIORITY_CLASS, 0, wdi...
by bussieck
3 weeks ago
Forum: Syntax
Topic: Dimension Different Error
Replies: 3
Views: 131

Re: Dimension Different Error

Just define set i and make an alias(i,j).

Hope this helps,
-Michael
by bussieck
3 weeks ago
Forum: Syntax
Topic: Dimension Different Error
Replies: 3
Views: 131

Re: Dimension Different Error

Hi,

k is a label (string) not a number, so you can't multiply this with a variable. If the label happens to represent a number you can use k.val (see https://www.gams.com/latest/docs/UG_GAM ... ams_Labels)

Hope this helps,
- Michael
by bussieck
4 weeks ago
Forum: Announcements
Topic: GAMS Distribution 24.9.2 (Minor Release) Announcement
Replies: 0
Views: 71

GAMS Distribution 24.9.2 (Minor Release) Announcement

Hi GAMS Users,

We started distributing GAMS Release 24.9.2 on November 14, 2017. This is a maintenance release.

You can download the software from https://www.gams.com/download/

Here are the release notes:
https://www.gams.com/latest/docs/RN_249.html

-Michael
by bussieck
1 month ago
Forum: Solvers
Topic: Computational time of model extremely increased
Replies: 9
Views: 394

Re: Computational time of model extremely increased

GAMS/Cplex (in default mode) runs deterministically when executed on the identical model instance on the same machine. There are a few options that can make it behave non-deterministically (only with option thread<>1). But even slight changes (e.g. the order of variables and equations, or a coeffici...
by bussieck
1 month ago
Forum: Solvers
Topic: how to reduce memory use of cplex
Replies: 3
Views: 500

Re: how to reduce memory use of cplex

It is not Cplex that runs out of memory, it is GAMS. You can try to clear some unset large parameters (option clear=sym;) but Cplex will most likely require a multiple of the memory used by GAMS. So rent a bigger machine. There are plenty of cloud offering that give you access to machines with plent...
by bussieck
2 months ago
Forum: Modeling
Topic: Simple Equilibrium problem with non-linear equations - division by zero
Replies: 2
Views: 180

Re: Simple Equilibrium problem with non-linear equations - division by zero

I think the GAMS error messages are quite useful: **** Exec Error at line 6: division by zero (0) Line 6 reads: 6 demand.. qd =e= beta/(p**ed) ; GAMS variables have there default level at 0. So move p.l away from 0: p.l=1; Next you get: **** Unmatched variable not free or fixed qs Qs is a positive v...