GAMS World Forum

Please share an example that allows other forum users to do what you are doing as suggested in the forum rules.

Fred

Here is the documentation of csv2gdx that comes with many examples.

You do not say what you would like to do with your example csv file. Should those numbers be elements of a one-dimensional set? If so, use I hope this helps.

Fred

You are right. This is because you define t as 1,2,...,51 in your code but in your data you use t1, t2, ..., t51. By default, GAMS does a filtered load meaning that zero records are loaded. The following should work. Sets t "time" /t1*t51/ Parameters X(t) Price for x at time t Y(t) Price f...

Hi, the index is part of the range you are reading. So start reading at A2 instead of B2 par=X rng=priceX!A2:B51 cdim=0 rdim=1 par=Y rng=priceY!A2:B51 cdim=0 rdim=1 par=Z rng=priceZ!A2:B51 cdim=0 rdim=1 Also note that the excel file name doe snot fit with your example code. I hope this helps! Fred

Setting limrow and limcol to 0 was already a god idea. In addition you might want to set solprint=0 to suppress the solution listing.

Fred

Hi, Assuming your set C contains the elements {i,j,k,l}, and j is just an element. Then, you can write the following: sum(C$(not C('j')), function_here) This is not exactly doing what was asked for. If C('j') exists this will result in not summing over any elements in C. I think what isinsuyildiz i...

Hi Johannes, You are most likely suffering from numerical issues due to the poor scaling of the model. With the latest version of GAMS and different solvers I get the following for 20220315_Modell_Vereinfacht_V3. - CBC: feasible - Cplex: integer infeasible - Gurobi: feasible - SCIP: infeasible - Xpr...

Nope. Even though Excel is available on the Mac, it does not support the MS Office OLE interface required by gdxxrw which is why gdxxrw is not available for mac/linux (see platform/tool availability matrix in our docs . So you either run gdxxrw on Windows and bring the GDX over to the Mac or export ...

Hi,

GDXXRW is a Windows only tool. Are you eventually trying to use it under a different OS?

Fred

Hi,

The post How do I formulate logical expressions in equations? from the FAQ may be helpful:

I hope this helps!

Fred