Build a local square grid around a point (km-based) and clip by radius (robust CRS handling)

Usage

smn_int_make_grid(
  lat,
  lon,
  cell_km = 5,
  radius_km = 20,
  clip = c("intersect", "centroid"),
  crs_out = 4326,
  return = c("polygons", "centroids", "both")
)

Arguments

lat: Numeric latitude of center (WGS84).
lon: Numeric longitude of center (WGS84).
cell_km: Numeric cell size in kilometers (default 1).
radius_km: Numeric radius (km) for square/round extent.
clip: Logical; clip by country polygon (if available).
crs_out: Output CRS EPSG code (default 4326).
return: Character: "sf" or "data.frame".