[Feature] Enable optional parameters for objective functions with functools

[samgdotson]

Currently, all objectives and constraints in osier require two items, the list of technologies and a solved dispatch model. Some calculations will require tunable parameters. Such as a volatility calculation using weighted_permutation_entropy, for example. Therefore, allowing users to specify the optional parameters at run time with some thing like:

objectives = (func1, functools.partial(func2, m = 7, tau=60))

Where the second objective function func2 has some optional parameters that cannot be set once a simulation begins (except by using functools.partial).

Edit:
To clarify the desired behavior, users should be able to pass a function and it's parameters to osier without explicitly calling functools.partial. E.g.,

from osier import CapacityExpansion

problem = CapacityExpansion(..., objectives=[func1, {func2: {m:7, tau:60}}], ...)

Users would be required to know which parameters they need.

Conversation

@yardasol @ZoeRichter @smpark7 @nsryan2 @munkm

Does this functionality make sense? Which version is clearer? The clarification would add more complexity to the osier.CapacityExpansion object, but it's already so similar to the functools implementation that I'm not sure anymore if the "simplification" makes sense. Looking for thoughts.

[smpark7]

From a user perspective, I think functools.partial should be abstracted away. Then the user would also not be required to import functools.

Will func1 be passed as is or as a key in its own dict paired with a None value? e.g., func1 or {func1: None}. Consistency with func2 would be nice.

[samgdotson]

Thanks @smpark7! This behavior is only for the cases where a function has some additional parameters, which would be ‘func2’ in this case. ‘func1’ is not modified so ‘osier’ can simply use it. This is what I would consider “advanced” usage. I’d rather not complicate the syntax too much by harmonizing the format. 9/10 times users would pass ‘func’:None.

[smpark7]

Okay if that's the case then just func1 is good.