GeoRegions.jl

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Backends for GeoRegions.jl ​

This page gives a brief summary of the backend process that GeoRegions.j uses to save manually defined custom GeoRegions for projects.

JSON files ​

All relevant information for a GeoRegion can be divided into two components:

  • String descriptors that identify a GeoRegion and make each GeoRegion unique

  • Geometry, or a vector of Geometries, that describe the geographic region itself

Ever since ≥v8, I have decided that JSON is the appropriate format to store this information. Therefore, each GeoRegion will have its own unique .json file, stored in the location $path/.georegions/$ID.json, where path is the directory of your project.

We use JSON3.jl to write and read these .json files, as JSON3.jl is able to take a struct and parse it into a readable JSON string.

Let's show an example

julia
using GeoRegions
geo = GeoRegion(
    [3,8,5,3],[40,-20,14,40],
    ID = "TSTjson", pID = "GLB", name = "Test Save GeoRegion",
    save = true, path = joinpath(pwd(),"jsoneg")
)
The GeoRegion TSTjson has the following properties:
    Region ID     (ID) : TSTjson
    Parent ID    (pID) : GLB
    Name        (name) : Test Save GeoRegion
    Bounds   (N,S,E,W) : 40.0, -20.0, 8.0, 3.0
    Rotation       (θ) : 0.0
    File Path   (path) : /home/runner/work/GeoRegions.jl/GeoRegions.jl/docs/build/tutorials/projects/jsoneg/.georegions/TSTjson.json
    Centroid (geometry.centroid) : [5.333333333333333, 11.333333333333334]
    Shape       (geometry.shape) : Vector{Point{2, Float64}}(4)

And let's read the string inside this file

julia
open(geo.path) do file
    read(file, String)
end
"{\"ID\":\"TSTjson\",\"pID\":\"GLB\",\"name\":\"Test Save GeoRegion\",\"rotation\":0.0,\"geometry\":{\"longitude\":[3.0,8.0,5.0,3.0],\"latitude\":[40.0,-20.0,14.0,40.0]}}"

Let's clean up the directory.

julia
rm(dirname(geo.path),recursive=true)