[Help wanted] Add dimension

[ThomasAuriel]

I would like to add a dimension to a raster object.

Currently i do this:

# Get a subset of the initial ds raster object
subDs = ds[Ti=At(time)]
# Add the time dimension to keep the time dimension
subDs = rebuild(subDs; dims=(subDs.dims..., Ti(time)))

Today, this code give me this error:

Internal Error: BoundsError: attempt to access Tuple{} at index [1]

(dims has the X and Y dimensions)

• Is it possible to keep the dimension when I retrieve a sub dataset ?
• Is it possible to add a dimension ?

[rafaqz]

You would need to add a dimension to the array at the same time or it wont match? rebuild is not fancy, it just uses what you give it.

But why no instead index with a range or vector:

subDs = ds[Ti=At([time])]

Then you wont lose the dimension

[ThomasAuriel]

Oh ! That's clever. I hadn't thought of that. It works as expected. Thank you.

For the second question:
Let's say later in my code I need to add a dimension, how could I do ?

Does RasterStack could be the solution ?

[rafaqz]

Yeah its a little harder...

With a base Array you can just add colons to indexing to get extra dimensions:

julia> zeros(2, 2)[:, :, :]
2×2×1 Array{Float64, 3}:
[:, :, 1] =
 0.0  0.0
 0.0  0.0

But here you also want to add a dimension. This should work fine if your array is a matrix:

subDs = rebuild(subDs; data=parent(subDs)[:, :, :], dims=(dims(subDs..., Ti(time)))

Its not a very common thing to do, so I'm not sure if it needs a function in DD.

(More common is using cat to add a dimension when joining arrays)