Make a new gGraph object from a custom hexagonal grid

This function constructs a new gGraph object based on a hexagonal discrete global grid system (DGGS) with a user-defined spatial resolution. The graph is restricted to a geographic bounding box defined by the user.

Usage

makeHexGrid(geo.box, spacing, ...)

Arguments

geo.box

A geographic bounding box. With either a named numeric vector with xmin, xmax, ymin, ymax or an object of class bbox or sf. Coordinates must be in longitude/latitude (EPSG:4326).

spacing

A positive numeric value giving the desired spacing (in km) of the discrete global grid. The closest available DGGS resolution is used.

...

Additional arguments passed to other methods (currently not used).

Value

A gGraph object representing the DGGS restricted to the specified geographic region. The @nodes.attr slot is empty.

Details

The function constructs a discrete global grid using the dggridR package, then identifies neighboring grid cells using the spdep package, and finally builds a gGraph object with the resulting graph structure and node coordinates.

Examples

# Define a geographic bounding box (e.g., for a region in Europe)
geo.box <- c(xmin = -10, xmax = 30, ymin = 35, ymax = 60)
# Create a gGraph with a spacing of 300 km
ggraph <- makeHexGrid(geo.box = geo.box, spacing = 300)
#> Resolution: 6, Area (km^2): 69967.8493448681, Spacing (km): 261.246386348549, CLS (km): 298.479323187169
plot(ggraph, edge = TRUE)
#> Spherical geometry (s2) switched off

#> 
#> No edge to plot.
#> Spherical geometry (s2) switched on