Your MESSAGEix GAMS Code

[Matthew Gidden]

Hello all,

(apologies for cross listing if you've gotten this message already)

During the recent push for public releases and easy installation, the location of the model files (i.e., GAMS code) has  been moved from the top-level folder into the "message_ix" folder to support our new conda installation procedure. 

Recognizing that it can be onerous to have to reinstall every time a change to the GAMS code is made, we also provide a new "message-ix config" utility. This will allow you to put the GAMS code anywhere on your system, edit it, and message_ix will read files from that location when reading/writing gdx and solving. You can keep your workflows exactly the same as before by executing messageix-config --model_path message_ix/model. Please note that this is done automatically for you if you use the install.bat installer.

To those users who have installed with conda, please be aware that a bug was observed with the config utility (#41) and corrected (#54). This correction will be made available in the next release on conda, and is thus only available on the current master branch at present. If you do not plan to change the GAMS code for your current work, this bugfix will not affect you.

Pasted below is the relevant section from the README:

Configure Model Files

By default, the model files are stored with your installation. Many users will simply want to run MESSAGEix, and will never need to see the these files; however, some users will want to edit the files directly to add new parameters, constraints, etc. Accordingly, we provide a utility to place the model files in a local directory of your choosing:

messageix-config --model_path /path/to/model 

Please note, if you cloned this repository and installed MESSAGEix with install.bat, this command has already been run, pointing to message_ix/model.

Cheers and happy modeling,

Matt