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mcontim / GeoGrids.jl

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GeoGrids.jl

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This is a package containing functions for Geographical Grids generation for example for terminals distribution for System Level Simulations. In the next version support for Geo Surface tesselation for cell grid layout will be supported.

Exported Functions

Icogrid

icogrid(;N=nothing, sepAng=nothing, unit=:rad, height=nothing, type=:lla)

This function returns a Vector of Point2 or LLA elements, for a N points Global grid built with the Fibonacci Spiral method.

The grid can be generated starting fom the number of point requested on the grid (N) or by the minimum separation angle requested for the points (sepAng).

The problem of how to evenly distribute points on a sphere has a very long history. Unfortunately, except for a small handful of cases, it still has not been exactly solved. Therefore, in nearly all situations, we can merely hope to find near-optimal solutions to this problem.

Of these near-optimal solutions, one of the most common simple methods is one based on the Fibonacci lattice or Golden Spiral or Fibonacci Spiral. Furthermore, unlike many of the other iterative or randomised methods such a simulated annealing, the Fibonacci spiral is one of the few direct construction methods that works for arbitrary N.

This method of points distribution is Area Preserving but not distance preserving.

When the selected output type is Point2, as convention it has been considered: LAT=x, LON=y and the output can be returned either in :deg or :rad units.

Icogrid

Meshgrid

rectgrid(xRes::ValidAngle; yRes::ValidAngle=xRes, height=nothing, unit=:rad, type=:lla)

This function returns a Matrix of Point2 or LLA elements representing a 2D Global grid of coordinates with the specified resolutions xRes and yRes respectively for x and y axes. This function return the LAT, LON meshgrid similar to the namesake MATLAB function.

When the selected output type is Point2, as convention it has been considered: LAT=x, LON=y and the output can be returned either in :deg or :rad units.

Meshgrid

Filtering

in_region(p::Union{LLA, Point2, AbstractVector, Tuple}, domain::Union{GeometrySet, PolyArea}) -> Bool
in_region(p::Union{LLA, Point2, AbstractVector, Tuple}, domain::Union{GeoRegion, PolyRegion}) -> Bool
in_region(points::Array{<:Union{LLA, Point2, AbstractVector, Tuple}}, domain::Union{GeometrySet, PolyArea}) -> Array{Bool}
in_region(points::Array{<:Union{LLA, Point2, AbstractVector, Tuple}}, domain::Union{GeoRegion, PolyRegion}) -> Array{Bool}

This function determines if a given point belongs to a 2-dimensional Meshes.Domain object. The Meshes.Domain object represents a geometric domain, which is essentially a 2D region in space, specified by its bounds and discretization.

The function first converts the input tuple into a Point object, which is then checked if it falls inside the given Meshes.Domain object. The Meshes.Domain can be either a GeometrySet or a PolyArea object.

filter_points(points::Union{Vector{LLA}, Vector{AbstractVector}, Vector{Point2}, Vector{Tuple}}, domain::Union{GeometrySet, PolyArea}) -> Vector{Input Type}
filter_points(points::Union{Vector{LLA}, Vector{AbstractVector}, Vector{Point2}, Vector{Tuple}}, domain::Union{GeoRegion, PolyRegion}) -> Vector{Input Type}

Returns the list of of points based on whether they fall within a specified geographical domain.

Poly Filter

Geo Filter 

extract_countries(r::GeoRegion)

Extracts the countries from a given region. The output represents the field domain of GeoRegion.

It first gets the field names of the GeoRegion type, excluding the :regionName, then maps these field names to their corresponding values in the GeoRegion instance r, creating a collection of pairs. It filters out any pairs where the value is empty. It converts this collection of pairs into a NamedTuple, finally, it calls GeoGrids.extract_countries with the NamedTuple as keyword arguments.

This function is an overload of GeoGrids.extract_countries that takes a GeoRegion object as input. It extracts the countries from the given region and returns them.

Useful Internal Functions

_meshgrid(xin,yin)

Create a 2D grid of coordinates using the input vectors xin and yin. The output, in the form of SVector(xout,yout), contains all possible combinations of the elements of xin and yin, with xout corresponding to the horizontal coordinates and yout corresponding to the vertical coordinates.

_icogrid(N::Int; coord::Symbol=:sphe, spheRadius=1.0)

This is the base function used by icogrid. This function generates N uniformly distributed points on the surface of a unitary sphere using the classic Fibonacci Spiral.

The output can be returned as a SVector of either, spherical or cartesian coordinates.

plot_geo_points(points; title="Point Position GEO Map", camera::Symbol=:twodim, kwargs_scatter=(;), kwargs_layout=(;))

This function takes an Array of Union{Point2,LLA,AbstractVector,Tuple} of LAT-LON coordinates and generates a plot on a world map projection using the PlotlyJS package.

The input is checked and the angles converted in deg if passed as Unitful and interpreted as rad if passed as Real values.