Allow non-constant observables

[sabinala]

Currently, parameters in observable expressions must be constant, but we should allow non-constant (or sampled) parameter values.

[SamWitty]

@sabinala , I believe observables can already support parameters values in their definitions. Do you have an example where this behavior does not work as expected?

[sabinala]

Hi @SamWitty, see here for an example: https://github.com/ciemss/pyciemss/blob/578-allow-non-constant-observables/docs/source/Params-in-observables.ipynb

[SamWitty]

Great, thank you. Could you please create an AMR at https://raw.githubusercontent.com/DARPA-ASKEM/simulation-integration/main/data/models/ so that I can add a test when I address this issue. I'll plan on taking this on now.

[sabinala]

@SamWitty Here's the PR to add that AMR: DARPA-ASKEM/simulation-integration#78