What i should GAMS use for the s(i)? The control of i stops with the sum. The equation is controlled over j.
-Michael
Search found 1046 matches
- 1 month ago
- Forum: Syntax
- Topic: A problem with parentheses
- Replies: 3
- Views: 1460
Re: A problem with parentheses
Not sure what editor you used, but GAMS does not like your "≤" nor the "∗". These are unicode characters not part of the GAMS language, hence the compiler gets confused. Just use the regular ASCII characters/character sequence "<=" and "*".
-Michael
-Michael
- 1 month ago
- Forum: Syntax
- Topic: $ifThen set X or Y
- Replies: 2
- Views: 4073
Re: $ifThen set X or Y
No, the "$if set" only works on a single compile time variable name, not an expression. You can work around this by having a parallel set of numerical compile time variables and then use $ifThenE: $set xset 0 $if set x $set xset 1 $set yset 0 $if set y $set yset 1 $log %xset%%yset% $ifThen...
- 2 months ago
- Forum: Announcements
- Topic: GAMS Distribution 46.1.0 (Major Release)
- Replies: 0
- Views: 4051
GAMS Distribution 46.1.0 (Major Release)
Hi GAMS Users,
We started distributing GAMS Release 46.1.0 on February 21, 2024.
You can download the software from https://www.gams.com/download/
Here are the release notes: https://www.gams.com/latest/docs/RN_46.html
Your GAMS Team
www.gams.com
We started distributing GAMS Release 46.1.0 on February 21, 2024.
You can download the software from https://www.gams.com/download/
Here are the release notes: https://www.gams.com/latest/docs/RN_46.html
Your GAMS Team
www.gams.com
- 3 months ago
- Forum: Announcements
- Topic: GAMS Distribution 46.0.0 (Beta Release)
- Replies: 0
- Views: 2646
GAMS Distribution 46.0.0 (Beta Release)
Hi GAMS Users, We would like to announce the availability of the GAMS Beta Release 46.0.0. Please consult the beta release notes for details about new features and updated solvers: https://www.gams.com/beta/docs/RN_46.html If you are interested in experimenting with this beta release, please downloa...
- 3 months ago
- Forum: Solvers
- Topic: BARON solver cannot handle the "Sign" function
- Replies: 2
- Views: 3833
Re: BARON solver cannot handle the "Sign" function
BARON only "understands" a subset of functions offered by GAMS. BARON, unlike local solvers like Conopt, need the algebra of the non-linear expression to build (linear) underestimators. It can do that for all operators (*,/,**,+,-) but not for all functions. The trig functions sin, cos, ta...
- 3 months ago
- Forum: Syntax
- Topic: SOS1 variable modelling
- Replies: 2
- Views: 2665
Re: SOS1 variable modelling
GAMS defines the membership of a variable to a SOS set by the last index in the SOS variable declaration. As a consequence of this you can't have a variable appear in two SOS sets. Your model has this (e.g. W(T2,2,U1) shows up in the first and second SOS set in your example). I have not seen models ...
- 4 months ago
- Forum: Solvers
- Topic: Issue of dual from energy/reserves balance constraint in optimization model
- Replies: 2
- Views: 13202
Re: Issue of dual from energy/reserves balance constraint in optimization model
In an LP there is no such thing as bounds on the dual. It is not unusal to get different dual solution with different solvers. With LPs you can have different optimal basis with different (primal and) dual solutions. Uniqueness in the optimal solution is very rare in practical models. If you want mo...
- 4 months ago
- Forum: Modeling
- Topic: GAMSPy model building
- Replies: 6
- Views: 25677
Re: GAMSPy model building
Thanks for sharing the code. The trouble is that the description of set "impact" had some funny characters which don't show when you look at the file in github ("impact categories like EUR or USD, CO 2 − eq") but do when you check this out on Windows and look at it in e.g. notepa...
- 5 months ago
- Forum: Syntax
- Topic: GAMSpy error
- Replies: 1
- Views: 10370
Re: GAMSpy error
I fear your screen shot is not enough to point you to the issue. Please share the entire Python script (or make a minimal example) so one can reproduce. If you are a licensed user and can't share the script here in the forum, you might want to consider to email support@gams.com with something that l...