Hi everyone,

I need help understanding how to count and interpret the number of variables in my model. My model currently shows a total of 435,000 single variables. However, I’m unsure if this is accurate, given that my license restricts the number of variables to 2,000.

I would appreciate any assistance you can offer.

Perhaps, you can share more information. For example the log file of your GAMS run.

-Michael

Hello everyone,

Attached is an image with the results I obtain from the file log. I would really like to know what “Block of variables” and “single variables” mean and how these variables relate to the license limits, since my license limits me to 2000 variables.

This is an optimization model that considers a 5-year period divided by months. I currently need to extend the period to 10 years, which will consequently increase the number of variables I have.

A block of variables/equations are symbolic variables and equations usually indexed over some sets, e.g. balance(i,j). The number of variable/equation blocks does not change with actual data (the set members of i and j). The single variables/equations are the unrolled variables and equations. So balance(‘i1’,‘j1’), balance(‘i1’,‘j2’) … Some GAMS licenses (demo and community) limit the number of single. i.e. unrolled variables and equations. So your model does need a professional license.

If you are in doubt if you use GAMS legally, I suggest to contact support@gams.com with your log, listing, and your license file.

-Michael