use array_like instead of numeric/array-like

[wholmgren]

The pvlib parameters/returns type documentation style is:

• numeric : scalar, np.array, pd.Series. Typically int or float dtype.
• array-like : np.array, pd.Series. Typically int or float dtype.

However, Numpy defines array_like as "Any sequence that can be interpreted as an ndarray. This includes nested lists, tuples, scalars and existing arrays."

I think we should follow the numpy standard. We lose the implied specification for whether or not a function works with scalar input, but this seems to be a source of confusion anyways. Instead, the docstrings for functions that require array input with length > 1 could explicitly state this.

[adriesse]

I think that using array-like in a different way from numpy is probably not such a good idea, but then perhaps we should just not use array-like at all? I have the impression that there are lots of pvlib functions that support only a subset of array-like.

I would prefer pvlib documentation to be more explicit, which might mean putting more than one word, e.g.:

• scalar
• list
• scalar or list

[percygautam]

Hey, @adriesse @wholmgren I am new to this library and would like to contribute. I have experience with documentation in sphinx. Kindly guide me in solving this issue.
Also, guide me on whether should I start working with this issue or with issue #476 ?

[wholmgren]

@percygautam thanks for your interest! Maybe you could run a couple of find/replace-all commands.

Note the contributing documentation contains some general suggestions for getting started with git/github.

[percygautam]

Thanks @wholmgren , I'll start exploring the documentation and would start working on issues.