Add custom constraints in MessageIX

[Alaa-Eltablawy]

Hello!

Is it possible to add custom constraints based on existing variables in MessageIX Python API?

Thanks!

[khaeru]

@Alaa-Eltablawy, do you mean “custom” constraints?

If you do, please edit your question & title.
If not, please provide a link or explanation of what “costume constraints” are.

[khaeru]

Okay, it seems "custom" was indeed intended.

The answer is yes, in some cases. See the sections of the documentation about:

• “Generic relations (linear constraints)” —this describes the GAMS variables and equations for these constraints, or ‘relations’.
• “Parameteters of the Relations section” —this describes the particular parameters in which data should be entered.

In general, per the first link, it is possible to construct a constraint on nearly any linear combination of ACT, CAP, and CAP_NEW values.

Since these are the ‘core’ decision variables for MESSAGE, the values of most other variables are closely related, and it is possible to effectively constrain them by careful construction of values for the parameters relation_activity, relation_new_capacity, and relation_total_capacity.