Make regional frequency analyses and uncertainties easier to use

[RondeauG]

Addressing a Problem?

I find that it can be quite difficult to know to use the regional frequency analysis module.

• Function names can be quite obscure, such as calc_q_iter or get_group_from_fit (that needs results from the PCA, not the fit).
• Function arguments are similarly not always evident. They also sometimes change from one function to another, such as n_samples vs. n.
• The order in which to use the functions is quite linear (I think?), but very difficult to know. I think that we can do a much better job in helping users.

Potential Solution

No response

Additional context

@TC-FF

Contribution

• [x] I would be willing/able to open a Pull Request to contribute this feature.

[TC-FF]

xhfa.uncertainties.calc_q_iter Since bv and var are inputs, it should return a da with .sel(id=bv)[var] and better yet, it should be possible to apply it on a da to return a da or on a ds to return a ds