Convert gridded data or a grid to sf

Methods for sf::st_as_sf(). Gridded data comes back as one feature per row, carrying either the centre of the cell each row fell in or that cell's boundary. A grid specification comes back as its global cell set.

Usage

# S3 method for class 'HexData'
st_as_sf(
  x,
  ...,
  geometry = c("point", "polygon"),
  shape = c("hexagon", "gosper", "descendants"),
  depth = 3L
)

# S3 method for class 'HexGridInfo'
st_as_sf(x, ...)

Arguments

x

A HexData or HexGridInfo object

...

For a HexGridInfo, passed on to grid_global

geometry

Type of geometry: "point" (default) or "polygon"

shape, depth

Cell shape for polygon geometry, as for cell_to_sf

Value

An sf object

Details

For point geometry, cell centers (cell_cen_lon, cell_cen_lat) are used. For polygon geometry, cell boundaries are computed using the grid specification.

See also

cell_to_sf for the cells of named cell IDs, grid_global for every cell of a grid

Examples

df <- data.frame(lon = c(0, 10, 20), lat = c(45, 50, 55))
result <- hexify(df, lon = "lon", lat = "lat", area_km2 = 1000)

# Get sf points
sf_pts <- st_as_sf(result)

# Get sf polygons
sf_poly <- st_as_sf(result, geometry = "polygon")

# Every cell of a coarse grid
cells <- st_as_sf(hex_grid(resolution = 2))