hexify_cell_to_sf: Convert cell IDs to sf polygons

In hexify: Equal-Area Hex Grids on the 'Snyder' 'ISEA' 'Icosahedron'

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,
  wrap_dateline = TRUE
)

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.
wrap_dateline	Logical. If TRUE (default), calls sf::st_wrap_dateline() to split antimeridian-crossing polygons. Set to FALSE for orthographic/globe projections where wrapping creates gaps.

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.

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)

See Also

cell_to_sf for the recommended S4 interface

Other sf conversion: hex_corners_to_sf(), hexify_grid_global(), hexify_grid_rect()

Examples

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")

hexify documentation built on March 1, 2026, 1:07 a.m.