Forward projection -> quantize -> cell centre -> inverse to lon/lat, on the
aperture-3 pipeline used by hexify(): points fold into the non-negative
quad frame (lonlat_to_cell()), and the centre comes back from the cell
itself (cell_to_lonlat()), so the returned centre is the centre of the
assigned cell.
Usage
hexify_assign(lon, lat, effective_res, make_polygons = FALSE)
Arguments
- lon, lat
numeric vectors (same length), degrees.
- effective_res
integer effective resolution (>= 1).
- make_polygons
logical; if TRUE, return an sf with hex polygons.
Value
data.frame with id (Z3 index string), face (quad, 0-11),
effective_res, center_lon, center_lat; if make_polygons=TRUE,
an sf with geometry column.