GAMS World Forum

In order to run this, we would need a GDX file. Can you supply one? Moreover, the export to Excel can be improved (performance). Rather than calling gdxxrw for each variable/parameter, you can create (at compile $on/offEcho or execution time $on/offPut) a gdxxrw instruction file: $if not %PrintResul...

What does "System limits" actually refers to in this context ? GAMS has some internal limits, e.g. the number of variables a model can have <2.1e9 and other limits. This is what this return code means. I am a little surprised that the log did not give you more information on what limit wa...

Sebastian,

On professional development. I can recommend Bruce McCarl's GAMS classes. He starts one next week. See https://www.gams.com/courses/.

-Michael

Not sure where you picked upo the idea to terminate the gdxxrw instructions with a semicolon (dset=i rng=Datos!B5 rDIM=1 ; ). With that gdxxrw tries to interprete 1; as a number and fails. Reading parameters requires reading and index and the numbers. With the instructions "par=Qfvmax rng=Datos...

No good explanations. The call works for me without problems. I can suggest that you try to run GDXXRW from the command line. Open a cmd windows (in the IDE use the MSDOS icon in the right top corner, with Studio use the file context menu and select Open Terminal). Now run "GDXXRW.EXE SAM-V2_0....

Why don't you share the GAMS log and provide access to the Excel workbook but uploading both files to the thread. -Michael

Most likely something with you statement "$CALL GDXXRW MLI_SAM2018.xlsx Par=SAM rng=D4:DD108" went wrong. Check the log for errors. You can also check the return code of gdxxrw for success by actually running "$CALL.checkErrorLevell GDXXRW ...". Perhaps, gdxxrw did not find the E...

Search for logic equations in the forum, there are plenty answers. -Michael

It's not. The (GAMS/Cplex) log says: "--- MIP status (118): integer unbounded". So add a lower bound to the objective (e.g. ZF.lo=-1e6) and see what variables "run away".

-Michael

The GAMS Lib model lop (https://www.gams.com/latest/gamslib_ml/ ... b_lop.html) and sroute (https://www.gams.com/latest/gamslib_ml/ ... route.html) determine the shortest path from all nodes to all other nodes.

-Michael