Convert cell IDs to sf polygons

Creates sf polygon geometries for hexagonal grid cells.

Usage

cell_to_sf(cell_id = NULL, grid, wrap_dateline = TRUE)

Arguments

cell_id

Numeric vector of cell IDs. If NULL and x is HexData, uses cells from x.

grid

A HexGridInfo or HexData object. If HexData and cell_id is NULL, polygons are generated for all cells in the data.

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.

Value

sf object with cell_id and geometry columns

Details

When called with a HexData object and no cell_id argument, this function generates polygons for all unique cells in the data, which is useful for plotting.

See also

hex_grid for grid specifications, as_sf for converting HexData to sf

Examples

# From grid specification
grid <- hex_grid(area_km2 = 1000)
cells <- lonlat_to_cell(c(0, 10, 20), c(45, 50, 55), grid)
polys <- cell_to_sf(cells, grid)

# From HexData (all cells)
df <- data.frame(lon = c(0, 10, 20), lat = c(45, 50, 55))
result <- hexify(df, lon = "lon", lat = "lat", area_km2 = 1000)
polys <- cell_to_sf(grid = result)