GeoGrids.jl

Appearance

Tessellation ​

GeoGrids.jl provides functionality for creating tessellated cell layouts on geographical regions. The package supports different tessellation types and can work with various region types.

Tessellation Types ​

GeoGrids.jl supports two main types of tessellation:

  • HEX: Hexagonal tessellation with either :pointy or :flat orientation
  • ICO: Icosahedral grid tessellation with customizable correction factor and pattern (:hex or :circle)

Global Tessellation ​

The simplest form of tessellation covers the entire globe using an icosahedral pattern:

julia
region = GlobalRegion()
centers, tiles = generate_tesselation(region, 1400e3, ICO(), EO())
plot = plot_geo_cells(centers, tiles; title="Global Icosahedral Tessellation")

Regional Tessellation ​

Geographical Region ​

You can create tessellations for specific countries or groups of countries:

julia
region = GeoRegion(admin="Italy;Spain")
centers, tiles = generate_tesselation(region, 50e3, HEX(), EO())
plot = plot_geo_cells(centers, tiles; title="Hexagonal Tessellation of Italy and Spain")

Latitude Belt Region ​

Create tessellations for specific latitude bands:

@example
region = LatBeltRegion(lim=(-10,10))
centers, tiles = generate_tesselation(region, 500e3, ICO(), EO())
plot = plot_geo_cells(centers, tiles; title="Equatorial Belt Tessellation")
to_documenter(plot) # hide

Custom Polygon Region ​

Define tessellations for custom polygon regions:

julia
region = PolyRegion(domain=[
    LatLon(10°, -5°),
    LatLon(10°, 15°),
    LatLon(27°, 15°),
    LatLon(27°, -5°)
])
centers, tiles = generate_tesselation(region, 100e3, HEX(), EO())
plot = plot_geo_cells(centers, tiles; title="Custom Region Tessellation")

Tessellation Parameters ​

Cell Size ​

The radius parameter (in meters) determines the size of the tessellation cells. This represents the nominal radius of each cell:

julia
# Small cells
region = GeoRegion(admin="Italy")
centers1, tiles1 = generate_tesselation(region, 25e3, HEX(), EO())
plot1 = plot_geo_cells(centers1, tiles1; title="25km Cell Radius")

Hexagonal Orientation ​

For HEX tessellation, you can choose between :pointy (default) and :flat orientations:

julia
# Pointy-topped hexagons
region = GeoRegion(admin="France")
centers1, tiles1 = generate_tesselation(region, 75e3, HEX(direction=:pointy), EO())
plot1 = plot_geo_cells(centers1, tiles1; title="Pointy-topped Hexagons")
julia
# Flat-topped hexagons
region = GeoRegion(admin="France")
centers2, tiles2 = generate_tesselation(region, 75e3, HEX(direction=:flat), EO())
plot2 = plot_geo_cells(centers2, tiles2; title="Flat-topped Hexagons")

Usage Notes ​

  • The actual cell sizes may vary slightly from the specified radius due to the Earth's curvature
  • For large regions, consider using larger cell sizes to maintain reasonable computation times
  • The EO parameter is used to generate both cell centers and tile boundaries
  • Cell boundaries are returned as vectors of points forming closed polygons