Convenience constructors for 1 and 2D grids?

[glwagner]

Some time ago I told @simone-silvestri I wanted to show a "simple 2D example" in a tutorial, to which he responded

It's actually harder to construct a 2D grid than a 3D grid

@simone-silvestri's point, I think, is that to reduce the dimension of a grid we have to pass topology with Flat elements. It's easier to construct a grid with the default topology (Periodic, Periodic, Bounded).

This has been haunting me ever since. I think one way we can solve this issue is to introduce convenience constructors like

grid = ZRectilinearGrid(size=16, z=(0, 1), topology=Bounded)
grid = XYRectilinearGrid(size=(64, 64), x=(0, 1), y=(0, 1), topology=(Periodic, Periodic))

These are relatively simple to implement since they're one-liners:

XYRectilinearGrid(args...; topology=(Periodic, Periodic), kw...) = XYRectilinearGrid(args...; kw..., topology=tuple(topology[1:2]..., Flat))

et cetera. We can also define the appropriate type aliases:

const XYRectilinearGrid{FT, TX, TY} = RectilinearGrid{FT, TX, TY, Flat} where {FT, TX, TY}

and change show (if we desire).

Is this friendly / a good idea?

[simone-silvestri]

I Think it is a good idea.

While we are at it, we can also introduce Flat directions for a the LatitudeLongitudeGrid

[francispoulin]

This is intuitive and a good idea moving forward. I like it!

[glwagner]

I'm closing this issue because I'm judging that it's not of current, timely relevance to Oceananigans development. If you would like to make it a higher priority or if you think the issue was closed in error please feel free to re-open.