GAMS World Forum

Seems that you are using a rather old GAMS system with Python 3.12? I suggest you get the latest GAMS from https://www.gams.com/download/ and then follow the tutorial . In general, please make sure to use the documentation that matches your installed version. Especially in the installation process o...

Hi,

Can you share the full log and lst file?
Does this issue occur with any model, e.g. trnsport from the model library?

If you do not want to share the information publicly, feel free to reach out to support@gams.com.

Fred

Hi, What kind of distributed parallel algorithm are you trying to run? The GAMS/Gurobi solver manual may have useful hints and instructions. I should need GAMS to provide a certificate for the distributed computing license. Not sure what that means and what this information is based on. Of course, y...

Can you please share you code, the log and the lst file?

Best,
Fred

Hi Rob, I cannot reproduce this issue. However, were able to trigger a similar exception from the preceding xlstalk call. The weird thing is, that we tried this across multiple machines and the issue is only occurring on some of them. So this has may have something to do with some Excel configuratio...

I don't think that Studio can be blamed for that. Let's assume you have a file a.gdx from a previous run. Now you run some model which contains ... * some call to create a.gdx, e.g. through GDXXRW $call gdxxrw ... o=a.gdx ... $gdxin a.gdx ... Now if I understand you correctly, you would expect GAMS ...

Hi Rob, Thanks for sharing. Some instructions on how to actually run this would be helpful. I assume I first have to run `1modOLC.gms` and then `2Simulation.gms`? Are there any command line parameters that need to be set? It could be helpful if you share the log of a run that shows that failure. Bes...

Hi, You are not controlling the `i` index in the equations properly. For equation connected, which element(s) of `i` should be used. It is not clear from how you define the equation. Maybe this equation should be generated for all elements in `i`? Then you need to use `i` in the equation domain. con...

Hi Rob,

Is it possible to share the Excel file and the gdxxrw command such that we can reproduce the issue?
It would also be good to know which GAMS version your are using.

Fred

Hi, Assuming that each activitys stars exacly once, the following should do he trick. alias(t,tt); startOnce(i).. sum(t, x(i,t)) =e= 1; forceActive(i,t).. sum(tt$[ord(t)<=ord(tt) and ord(tt)<=ord(t)+d(i)-1], y(i,tt)) =g= x(i,t)*d(i); forceInactive(i,t).. y(i,t) =l= sum(tt$[ord(t)-d(i)+1<=ord(tt) and...