Is it possible to set initial values for the optimization with MESSAGE to improve speed?

[SongminYu]

For large-scale models with MESSAGE, I feel it helpful, if possible, to set initial values for the optimization. I don't know if it is possible with the current MESSAGE, or if someone could share some experience on this. Thanks!

[glatterf42]

For ixmp with the Java backend (JDBC), this is currently not possible as it is hardcoded in the function that writes a Scenario to a GDX file that variables and equations are not included (and I'm assuming you're only interested in providing initial values for these). You could adopt this function to accept a parameter include_variables_and_equations to enable writing these to GDX, but once they are there, I don't know if GAMS automatically knows how to handle them.
For ixmp with the Python backend (ixmp4) such a parameter already exists. However, it's all or nothing: either you write all variables and equations to GDX or none of them. In addition to not being sure if GAMS handles them well automatically, I don't know if it can handle e.g. OBJ being in the input file. If this is not at all possible, the ixmp4 writing function also needs adjustment in any case.

[khaeru]

This is an existing feature request: #569

[glatterf42]

I knew that sounded familiar, but somehow couldn't find the PR. Thanks :)