GAMS World Forum

Hi, If you need to use x(i,j) and x(j,i), then you should not declare variable x with domain (i,j). If sets i and j both describe subsets of nodes, you can declare a superset of nodes and make i and j subsets of this superset. Then you can declare x over the superset of all nodes and should be good,...

Hi,

You could use GAMS Connect which can read/write Excel files and is platform independent.

I hope this helps!

Fred

Hi,

You could use GAMS Connect which can read/write Excel files and is platform independent.

I hope this helps!

Fred

Hi Teo, If I understand correctly, you are are solving 121 models. The Report summary belongs to a particular solve, so you should get 121 report summaries in total. So the 8 infeasibilities refer to a particular solve where e.g. 8 constraints may be violated in the returned infeasible "solutio...

Hi,

in the pin view you can look at two gms files side by side.

I hope this helps!

Fred

Hi, The information provided is not sufficient to help. You seem to have declared some symbol with different domain sets than used in the shared code snippet. But since you did not share the declarations, it is impossible to pinpoint the source if the issue. I suggest to follow the forum rules and ....

Hi Martina, It seems that what you need is a 2-dimensional dynamic set that maps values of G, q; Please consider the following examples: set G /A,B/ q /1*4/ Gq(G,q) / A.(1,2), B.(1*4) / ; display Gq; variable x(G,q); equation e; e.. sum(Gq(G,q), x(G,q)) =e= ... I hope this helps! Fred

Hi pnong, Scheduling problems are known to be challenging. Besides finding good feasible solutions (which seems to work okay for this model), solvers also work on improving the best known bound. I fed your problem into several state-of-the-art MIP solvers. After 10 minutes, they all provide a soluti...

Hi Antonio,

As you noticed GAMS 41.4.0 still comes with Gurobi 9.5.2. Gurobi 10 will be part of the upcoming GAMS 42 release. The beta release of GAMS 42 is planned for mid January.

Best,
Fred

In the meantime, the configuration editor has been added to GAMS Studio and allows users to conveniently point to a license file.