Search found 662 matches

by bussieck
3 days ago
Forum: Syntax
Topic: Reading time format from excel file
Replies: 4
Views: 653

Re: Reading time format from excel file

Your code still does not have the t set, a one dimensional index over the entire time. So if you would have this as explained in my example and declare your data2 over t instead of ho,sc (or s,h in my example), this would be easy: data2(t,'up')= data(t,'max')-data(t-1,'min'); With your code this is ...
by bussieck
3 days ago
Forum: Solvers
Topic: Feasible with conopt3 but not conop4
Replies: 3
Views: 101

Re: Feasible with conopt3 but not conop4

Yann, I have not seen this behavior in recent versions of Conopt4. It could be a scaling issue but without more details it's hard to say. You might want to send the point/solution found by Conopt3 through Examiner (https://www.gams.com/latest/docs/S_EXAMINER.html) and check externally the feasiblity...
by bussieck
1 week ago
Forum: Syntax
Topic: Lp status () infeasible
Replies: 1
Views: 142

Re: Lp status () infeasible

Please don't paste code as regular text. Use attachments or the code tags. Moreover, we can't really help because we don't have the data. So you would need to attach the GDX file. BTW, infeasible models are an okay outcome of optimization models. Bruce McCarl has nicely written up how to deal with i...
by bussieck
1 week ago
Forum: Syntax
Topic: Map two sets via an intermediate set
Replies: 2
Views: 157

Re: Map two sets via an intermediate set

The solution of my colleague Atharv works correctly and well. For very large data parallel assignment statements are way faster than loops, so in case you have very large data you might want to know how to do this fast with parallel assignment statements. The trick is to first build a three dimensio...
by bussieck
2 weeks ago
Forum: Syntax
Topic: Export result (CSV) in a loop
Replies: 1
Views: 788

Re: Export result (CSV) in a loop

It would help if you post the related source lines that create this error. I assume you try to declare a put file inside the loop and somehow use the loop set index as a file name. That's not possible, but with the put_utility 'ren' (https://www.gams.com/37/docs/UG_Put.html#UG_Put_PutUtil) you can r...
by bussieck
2 weeks ago
Forum: Announcements
Topic: GAMS Distribution 37.1.0 (Major Release)
Replies: 0
Views: 598

GAMS Distribution 37.1.0 (Major Release)

Hi GAMS Users,

We started distributing GAMS Release 37.1.0 on November 11, 2021.

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

Here are the release notes: https://www.gams.com/latest/docs/RN_37.html

Your GAMS Team
www.gams.com
by bussieck
2 weeks ago
Forum: Syntax
Topic: Save loop results including Solve
Replies: 3
Views: 524

Re: Save loop results including Solve

Thanks for sharing the data. Nevertheless, I don't get it. I give you three solutions to your problem. Do don't take any of them and implement your own solution that still doesn't work and you ask again for help. Please try one of the solutions I gave in my first answer.

-Michael
by bussieck
2 weeks ago
Forum: Solvers
Topic: Node limit exceeded. Set model attribute nodlim.
Replies: 4
Views: 1059

Re: Node limit exceeded. Set model attribute nodlim.

When using a solver it is important to understand the log. The "Optimal Solution" you point out is the optimal solution for the relaxed problem that SBB solves first. With out solving the relaxed problem to optimality there is no point to do any branch-and-bound. At default (node limit 1000) SBB has...
by bussieck
2 weeks ago
Forum: Syntax
Topic: Error =Error 32: The process cannot the file because it is being used by another process
Replies: 1
Views: 433

Re: Error =Error 32: The process cannot the file because it is being used by another process

This can be all sort of things, e.g. virus scanner interfering with the GAMS files. The log indicates that GAMS is at a stage where it tries to reopen the LST file and can't do this. In order to avoid GAMS going out of memory and constantly reopening the LST and other files, you could try to run you...
by bussieck
2 weeks ago
Forum: Syntax
Topic: Save loop results including Solve
Replies: 3
Views: 524

Re: Save loop results including Solve

First a few remarks: Please attach a file instead of pasting the code if you communicate a larger model or at least put it in a code section. Make sure someone else can run your model. In your case the Excel file is missing and even with that the loop at the end would not compiler. W is unknown, and...