Persistent Solvers should support IndexVars

[leroum]

Summary

It would be very helpful if the persistent solver would support updating IndexedVars in the model.

Rationale

When using pyomo through an application like oemof, it would be awsome to use the persitant solver. But when the original model containts IndexedVars it is not possible to update those vars or single entrys of them. This makes the persitant solver functionality not useable with those applications.

[michaelbynum]

Can you be more specific? Which persistent solver are you trying to use? It should be possible to update indexed variables with:

for k, v in m.x.items():
    opt.update_var(v)

[mrmundt]

@leroum - Can you please answer @michaelbynum 's question? We see that this is a popular request, so we'd like to know more.

[leroum]

Sorry for the late answer. I wanted to investigate a bit more after the information that it should work with the loop.

I am using gurobi_persistent and for indexed vars the update_var() function does not work even when using the loop. Where as the set_instance() functionality works fine.

[michaelbynum]

@leroum - do you get an error? If so, can you post the stack trace?

[leroum]

No i dont get an error message. The model is simply not updated in the persititant solver.