hexify_cell_to_sf: Convert cell IDs to sf polygons

Description

Creates polygon geometries for hexagonal grid cells from their cell IDs. Returns an sf object by default, or a data frame for lightweight workflows.

Usage

hexify_cell_to_sf(
  cell_id,
  resolution = NULL,
  aperture = NULL,
  return_sf = TRUE,
  grid = NULL
)

Value

If return_sf = TRUE: sf object with columns:

cell_id: Cell identifier
geometry: POLYGON geometry (sfc_POLYGON)

If return_sf = FALSE: data frame with columns:

cell_id: Cell identifier
lon: Vertex longitude
lat: Vertex latitude
order: Vertex order (1-7, 7 closes the polygon)

Arguments

cell_id: Integer vector of cell identifiers
resolution: Grid resolution level. Can be omitted if grid is provided.
aperture: Grid aperture: 3, 4, or 7. Can be omitted if grid is provided.
return_sf: Logical. If TRUE (default), returns sf object with polygon geometries. If FALSE, returns data frame with vertex coordinates.
grid: Optional HexGridInfo object. If provided, resolution and aperture are extracted from it.

Details

This function uses a native C++ implementation that is significantly faster than 'dggridR' polygon generation, especially for large numbers of cells.

For the recommended S4 interface, use cell_to_sf instead.

Examples

Run this code

library(hexify)

# Generate some data with hex cells
df <- data.frame(lon = c(0, 5, 10), lat = c(45, 46, 45))
result <- hexify(df, lon = "lon", lat = "lat", area = 1000)

# Get polygons as sf object (using HexData)
polys <- cell_to_sf(grid = result)

# Or with explicit parameters
polys <- hexify_cell_to_sf(result@cell_id, resolution = 10, aperture = 3)

# Plot with sf
library(sf)
plot(st_geometry(polys), col = "lightblue", border = "blue")