make_location_grid: Make a grid over a location bounding box

In elipousson/overedge: Assorted Functions For Easier Map Making

Make a grid over a location bounding box

Description

Create a grid with an id column and optionally a set number of columns and rows. This documentation is incomplete the function may change.

Usage

make_location_grid(
  location = NULL,
  dist = NULL,
  diag_ratio = NULL,
  asp = NULL,
  unit = "meter",
  crs = NULL,
  cols = NULL,
  rows = NULL,
  gutter = 0,
  desc = FALSE,
  n = NULL,
  cellsize = NULL,
  what = NULL,
  style = "rect",
  .id = "id"
)

Arguments

location	A sf, sfc, or bbox object, Default: NULL. Required.
dist	buffer distance in units. Optional.
diag_ratio	ratio of diagonal distance of area's bounding box used as buffer distance. e.g. if the diagonal distance is 3000 meters and the "diag_ratio = 0.1" a 300 meter will be used. Ignored when dist is provided.
asp	Aspect ratio of width to height as a numeric value (e.g. 0.33) or character (e.g. "1:3"). If numeric, get_asp() returns the same value without modification.
unit	Units for buffer. Supported options include "meter", "foot", "kilometer", and "mile", "nautical mile" Common abbreviations (e.g. "km" instead of "kilometer") are also supported. Distance in units is converted to units matching GDAL units for x; defaults to "meter"
crs	Coordinate reference system of bounding box to return
cols, rows	Used to set n if either are not NULL; defaults to NULL. row and id are added as columns to the grid if they are provided.
gutter	Distance in units between each column cell; gutter effectively serves as a margin as the negative buffer is applied to all cells (including those at the edges of the grid).
desc	If TRUE, reverse standard order of cell id numbering; defaults FALSE
n	If n is NULL and square is TRUE, the grid is set automatically to be 10 cells wide, Default: NULL
cellsize	target cellsize
what	"polygons", "corners", "centers"; set to centers automatically if style is "circle", "circle_offset" but a buffer is applied to return circular polygons.
style	Style of cell to return with options including "rect", "square", "hex", "flat_top_hex", "circle", "circle_offset"
.id	A name to use for the cell id column.

See Also

sf::st_make_grid

Examples

nc <- read_sf_path(system.file("shape/nc.shp", package = "sf"))

# Make a 4 by 5 grid covering a mile buffer around a location
make_location_grid(
  location = nc[24,],
  dist = 1,
  unit = "mile",
  cols = 4,
  rows = 5
)

# Make a 2 by 2 grid across a location with a 1000 meter gutter between each cell
make_location_grid(
  location = nc[24,],
  dist = 500,
  unit = "meter",
  cols = 2,
  rows = 2,
  gutter = 1000
)

elipousson/overedge documentation built on Aug. 13, 2022, 7:41 p.m.