Create and Format Geography Vectors

These functions create and export geography vectors. Unlike the BigQuery geography constructors, these functions do not sanitize invalid or redundant input using s2_union(). Note that when creating polygons using s2_make_polygon(), rings can be open or closed.

s2_geog_point(longitude, latitude)

s2_make_line(longitude, latitude, feature_id = 1L)

s2_make_polygon(
  longitude,
  latitude,
  feature_id = 1L,
  ring_id = 1L,
  oriented = FALSE,
  check = TRUE
)

s2_geog_from_text(wkt_string, oriented = FALSE, check = TRUE)

s2_geog_from_wkb(wkb_bytes, oriented = FALSE, check = TRUE)

s2_as_text(x, precision = 16, trim = TRUE)

s2_as_binary(x, endian = wk::wk_platform_endian())

Arguments

longitude, latitude	Vectors of latitude and longitude
feature_id, ring_id	Vectors for which a change in sequential values indicates a new feature or ring. Use `factor()` to convert from a character vector.
oriented	TRUE if polygon ring directions are known to be correct (i.e., exterior rings are defined counter clockwise and interior rings are defined clockwise).
check	Use `check = FALSE` to skip error on invalid geometries
wkt_string	Well-known text
wkb_bytes	A `list()` of `raw()`
x	geography vectors. These inputs are passed to `as_s2_geography()`, so you can pass other objects (e.g., character vectors of well-known text) directly.
precision	The number of significant digits to export when writing well-known text. If `trim = FALSE`, the number of digits after the decimal place.
trim	Should trailing zeroes be included after the decimal place?
endian	The endian-ness of the well-known binary. See `wk::wkb_translate_wkb()`.

Examples

# create point geographies using coordinate values:
s2_geog_point(-64, 45)
#> <s2_geography[1]>
#> [1] <POINT (-64 45)>

# create line geographies using coordinate values:
s2_make_line(c(-64, 8), c(45, 71))
#> <s2_geography[1]>
#> [1] <LINESTRING (-64 45, 8 71)>

# optionally, separate features using feature_id:
s2_make_line(
  c(-64, 8, -27, -27), c(45, 71, 0, 45),
  feature_id = c(1, 1, 2, 2)
)
#> <s2_geography[2]>
#> [1] <LINESTRING (-64 45, 8 71)>  <LINESTRING (-27 0, -27 45)>

# create polygon geographies using coordinate values:
# (rings can be open or closed)
s2_make_polygon(c(-45, 8, 0), c(64, 71, 90))
#> <s2_geography[1]>
#> [1] <POLYGON ((-45 64, 8 71, 0 90, -45 64))>

# optionally, separate rings and/or features using
# ring_id and/or feature_id
s2_make_polygon(
  c(20, 10, 10, 30, 45, 30, 20, 20, 40, 20, 45),
  c(35, 30, 10, 5, 20, 20, 15, 25, 40, 45, 30),
  feature_id = c(rep(1, 8), rep(2, 3)),
  ring_id = c(1, 1, 1, 1, 1, 2, 2, 2, 1, 1, 1)
)
#> <s2_geography[2]>
#> [1] <POLYGON ((20 35, 10 30, 10 10, 30 5, 45 20...>
#> [2] <POLYGON ((40 40, 20 45, 45 30, 40 40))>       

# import and export well-known text
(geog <- s2_geog_from_text("POINT (-64 45)"))
#> <s2_geography[1]>
#> [1] <POINT (-64 45)>
s2_as_text(geog)
#> [1] "POINT (-64 44.99999999999999)"

# import and export well-known binary
(geog <- s2_geog_from_wkb(wk::as_wkb("POINT (-64 45)")))
#> <s2_geography[1]>
#> [1] <POINT (-64 45)>
s2_as_binary(geog)
#> [[1]]
#>  [1] 01 01 00 00 00 00 00 00 00 00 00 50 c0 ff ff ff ff ff 7f 46 40
#> 
#> attr(,"class")
#> [1] "blob"

Arguments

See also

Examples