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Title:	Spherical Geometry Operators Using the S2 Geometry Library
Version:	1.1.9
Description:	Provides R bindings for Google's s2 library for geometric calculations on the sphere. High-performance constructors and exporters provide high compatibility with existing spatial packages, transformers construct new geometries from existing geometries, predicates provide a means to select geometries based on spatial relationships, and accessors extract information about geometries.
License:	Apache License (== 2.0)
Encoding:	UTF-8
LazyData:	true
RoxygenNote:	7.3.2
SystemRequirements:	cmake, OpenSSL >= 1.0.1, Abseil >= 20230802.0
LinkingTo:	Rcpp, wk
Imports:	Rcpp, wk (≥ 0.6.0)
Suggests:	bit64, testthat (≥ 3.0.0), vctrs
URL:	https://r-spatial.github.io/s2/,https://github.com/r-spatial/s2,http://s2geometry.io/
BugReports:	https://github.com/r-spatial/s2/issues
Depends:	R (≥ 3.0.0)
Config/testthat/edition:	3
NeedsCompilation:	yes
Packaged:	2025-05-23 14:44:45 UTC; edzer
Author:	Dewey Dunnington [aut], Edzer Pebesma [aut, cre], Ege Rubak [aut], Jeroen Ooms [ctb] (configure script), Google, Inc. [cph] (Original s2geometry.io source code)
Maintainer:	Edzer Pebesma <edzer.pebesma@uni-muenster.de>
Repository:	CRAN
Date/Publication:	2025-05-23 15:50:02 UTC

s2: Spherical Geometry Operators Using the S2 Geometry Library

Description

Provides R bindings for Google's s2 library for geometric calculations on the sphere. High-performance constructors and exporters provide high compatibility with existing spatial packages, transformers construct new geometries from existing geometries, predicates provide a means to select geometries based on spatial relationships, and accessors extract information about geometries.

Author(s)

Maintainer: Edzer Pebesmaedzer.pebesma@uni-muenster.de (ORCID)

Authors:

• Dewey Dunningtondewey@fishandwhistle.net (ORCID)

• Ege Rubakrubak@math.aau.dk

Other contributors:

• Jeroen Oomsjeroen.ooms@stat.ucla.edu (configure script) [contributor]

• Google, Inc. (Original s2geometry.io source code) [copyright holder]

See Also

Useful links:

• https://r-spatial.github.io/s2/

• https://github.com/r-spatial/s2

• http://s2geometry.io/

• Report bugs athttps://github.com/r-spatial/s2/issues

Create an S2 Geography Vector

Description

Geography vectors are arrays of points, lines, polygons, and/or collectionsof these. Geography vectors assume coordinates are longitude and latitudeon a perfect sphere.

Usage

as_s2_geography(x, ...)s2_geography()## S3 method for class 's2_geography'as_s2_geography(x, ...)## S3 method for class 'wk_xy'as_s2_geography(x, ...)## S3 method for class 'wk_wkb'as_s2_geography(x, ..., oriented = FALSE, check = TRUE)## S3 method for class 'WKB'as_s2_geography(x, ..., oriented = FALSE, check = TRUE)## S3 method for class 'blob'as_s2_geography(x, ..., oriented = FALSE, check = TRUE)## S3 method for class 'wk_wkt'as_s2_geography(x, ..., oriented = FALSE, check = TRUE)## S3 method for class 'character'as_s2_geography(x, ..., oriented = FALSE, check = TRUE)## S3 method for class 'logical'as_s2_geography(x, ...)## S3 method for class 's2_geography'as_wkb(x, ...)## S3 method for class 's2_geography'as_wkt(x, ...)

Arguments

Details

The coercion functionas_s2_geography() is used to wrap the inputof most functions in the s2 package so that you can use other objects withan unambiguious interpretation as a geography vector. Geography vectorshave a minimalvctrs implementation, so you canuse these objects in tibble, dplyr, and other packages that use the vctrsframework.

Value

An object with class s2_geography

See Also

s2_geog_from_wkb(),s2_geog_from_text(),s2_geog_point(),s2_make_line(),s2_make_polygon() for other ways tocreate geography vectors, ands2_as_binary() ands2_as_text()for other ways to export them.

S2 Geography Transformations

Description

These functions operate on one or more geography vectors andreturn a geography vector.

Usage

s2_boundary(x)s2_centroid(x)s2_closest_point(x, y)s2_minimum_clearance_line_between(x, y)s2_difference(x, y, options = s2_options())s2_sym_difference(x, y, options = s2_options())s2_intersection(x, y, options = s2_options())s2_union(x, y = NULL, options = s2_options())s2_snap_to_grid(x, grid_size)s2_simplify(x, tolerance, radius = s2_earth_radius_meters())s2_rebuild(x, options = s2_options())s2_buffer_cells(  x,  distance,  max_cells = 1000,  min_level = -1,  radius = s2_earth_radius_meters())s2_convex_hull(x)s2_centroid_agg(x, na.rm = FALSE)s2_coverage_union_agg(x, options = s2_options(), na.rm = FALSE)s2_rebuild_agg(x, options = s2_options(), na.rm = FALSE)s2_union_agg(x, options = s2_options(), na.rm = FALSE)s2_convex_hull_agg(x, na.rm = FALSE)s2_point_on_surface(x, na.rm = FALSE)

Arguments

Model

The geometry model indicates whether or not a geometry includes its boundaries.Boundaries of line geometries are its end points.OPEN geometries do not contain their boundary (model = "open"); CLOSEDgeometries (model = "closed") contain their boundary; SEMI-OPEN geometries(model = "semi-open") contain half of their boundaries, such that when two polygonsdo not overlap or two lines do not cross, no point exist that belong tomore than one of the geometries. (This latter form, half-closed, isnot present in the OpenGIS "simple feature access" (SFA) standard nor DE9-IM onwhich that is based). The default values fors2_contains() (open)and covers/covered_by (closed) correspond to the SFA standard specificationof these operators.

See Also

BigQuery's geography function reference:

• ST_BOUNDARY

• ST_CENTROID

• ST_CLOSESTPOINT

• ST_DIFFERENCE

• ST_INTERSECTION

• ST_UNION

• ST_SNAPTOGRID

• ST_SIMPLIFY

• ST_UNION_AGG

• ST_CENTROID_AGG

Examples

# returns the boundary:# empty for point, endpoints of a linestring,# perimeter of a polygons2_boundary("POINT (-64 45)")s2_boundary("LINESTRING (0 0, 10 0)")s2_boundary("POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))")# returns the area-weighted centroid, element-wises2_centroid("POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))")s2_centroid("LINESTRING (0 0, 10 0)")# s2_point_on_surface guarantees a point on surface# Note: this is not the same as st_point_on_surfaces2_centroid("POLYGON ((0 0, 10 0, 1 1, 0 10, 0 0))")s2_point_on_surface("POLYGON ((0 0, 10 0, 1 1, 0 10, 0 0))")# returns the unweighted centroid of the entire inputs2_centroid_agg(c("POINT (0 0)", "POINT (10 0)"))# returns the closest point on x to ys2_closest_point(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  "POINT (0 90)" # north pole!)# returns the shortest possible line between x and ys2_minimum_clearance_line_between(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  "POINT (0 90)" # north pole!)# binary operations: difference, symmetric difference, intersection and unions2_difference(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  "POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))",  # 32 bit platforms may need to set snap rounding  s2_options(snap = s2_snap_level(30)))s2_sym_difference(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  "POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))",  # 32 bit platforms may need to set snap rounding  s2_options(snap = s2_snap_level(30)))s2_intersection(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  "POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))",  # 32 bit platforms may need to set snap rounding  s2_options(snap = s2_snap_level(30)))s2_union(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  "POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))",  # 32 bit platforms may need to set snap rounding  s2_options(snap = s2_snap_level(30)))# s2_convex_hull_agg builds the convex hull of a list of geometriess2_convex_hull_agg(  c(    "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",    "POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))"  ))# use s2_union_agg() to aggregate geographies in a vectors2_coverage_union_agg(  c(    "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",    "POLYGON ((5 5, 15 5, 15 15, 5 15, 5 5))"  ),  # 32 bit platforms may need to set snap rounding  s2_options(snap = s2_snap_level(30)))# snap to grid rounds coordinates to a specified grid sizes2_snap_to_grid("POINT (0.333333333333 0.666666666666)", 1e-2)

Compute feature-wise and aggregate bounds

Description

s2_bounds_rect() returns a bounding latitude-longituderectangle that contains the region;s2_bounds_cap() returns a bounding circlerepresented by a centre point (lat, lng) and an angle. The bound may not be tightfor points, polylines and geometry collections. The rectangle returned may depend onthe order of points or polylines.lng_lo values larger thanlng_hi indicateregions that span the antimeridian, see the Fiji example.

Usage

s2_bounds_cap(x)s2_bounds_rect(x)

Arguments

Value

Both functions return adata.frame:

• s2_bounds_rect(): Columnsminlng,minlat,maxlng,maxlat (degrees)

• s2_bounds_cap(): Columnslng,lat,angle (degrees)

Examples

s2_bounds_cap(s2_data_countries("Antarctica"))s2_bounds_cap(s2_data_countries("Netherlands"))s2_bounds_cap(s2_data_countries("Fiji"))s2_bounds_rect(s2_data_countries("Antarctica"))s2_bounds_rect(s2_data_countries("Netherlands"))s2_bounds_rect(s2_data_countries("Fiji"))

Create S2 Cell vectors

Description

The S2 cell indexing system forms the basis for spatial indexingin the S2 library. On their own, S2 cells can represent pointsor areas. As a union, a vector of S2 cells can approximate aline or polygon. These functions allow direct access to theS2 cell indexing system and are designed to have minimal overheadsuch that looping and recursion have acceptable performancewhen used within R code.

Usage

s2_cell(x = character())s2_cell_sentinel()s2_cell_invalid()as_s2_cell(x, ...)## S3 method for class 's2_cell'as_s2_cell(x, ...)## S3 method for class 'character'as_s2_cell(x, ...)## S3 method for class 's2_geography'as_s2_cell(x, ...)## S3 method for class 'wk_xy'as_s2_cell(x, ...)## S3 method for class 'integer64'as_s2_cell(x, ...)new_s2_cell(x)

Arguments

Details

Under the hood, S2 cell vectors are represented in R as vectorsof typedouble(). This works because S2 cell identifiers are64 bits wide, as aredoubles on all systems where R runs (Thesame trick is used by the bit64 package to represent signed64-bit integers). As a happy accident,NA_real_ is not a validor meaningful cell identifier, so missing value support in theway R users might expect is preserved. It is worth noting thatthe underlying value ofs2_cell_sentinel() would normally beconsideredNA; however, as it is meaningful and useful whenprogramming with S2 cells, customis.na() and comparison methodsare implemented such thats2_cell_sentinel() is greater thanall valid S2 cells and not considered missing. Users can and shouldimplement compiled code that uses the underlying bytes of thevector, ensuring that the class of any returned object that shouldbe interpreted in this way is constructed withnew_s2_cell().

Value

An object of class s2_cell

Examples

s2_cell("4b59a0cd83b5de49")as_s2_cell(s2_lnglat(-64, 45))as_s2_cell(s2_data_cities("Ottawa"))

S2 cell operators

Description

S2 cell operators

Usage

s2_cell_is_valid(x)s2_cell_debug_string(x)s2_cell_to_lnglat(x)s2_cell_center(x)s2_cell_boundary(x)s2_cell_polygon(x)s2_cell_vertex(x, k)s2_cell_level(x)s2_cell_is_leaf(x)s2_cell_is_face(x)s2_cell_area(x, radius = s2_earth_radius_meters())s2_cell_area_approx(x, radius = s2_earth_radius_meters())s2_cell_parent(x, level = -1L)s2_cell_child(x, k)s2_cell_edge_neighbour(x, k)s2_cell_contains(x, y)s2_cell_distance(x, y, radius = s2_earth_radius_meters())s2_cell_max_distance(x, y, radius = s2_earth_radius_meters())s2_cell_may_intersect(x, y)s2_cell_common_ancestor_level(x, y)s2_cell_common_ancestor_level_agg(x, na.rm = FALSE)

Arguments

Create S2 Cell Union vectors

Description

Create S2 Cell Union vectors

Usage

s2_cell_union(x = list())## S3 method for class 's2_cell_union'as_s2_geography(x, ...)as_s2_cell_union(x, ...)## S3 method for class 's2_cell_union'as_s2_cell_union(x, ...)## S3 method for class 's2_cell'as_s2_cell_union(x, ...)## S3 method for class 'character'as_s2_cell_union(x, ...)

Arguments

Value

An object of class "s2_cell_union".

S2 cell union operators

Description

S2 cell union operators

Usage

s2_cell_union_normalize(x)s2_cell_union_contains(x, y)s2_cell_union_intersects(x, y)s2_cell_union_intersection(x, y)s2_cell_union_union(x, y)s2_cell_union_difference(x, y)s2_covering_cell_ids(  x,  min_level = 0,  max_level = 30,  max_cells = 8,  buffer = 0,  interior = FALSE,  radius = s2_earth_radius_meters())s2_covering_cell_ids_agg(  x,  min_level = 0,  max_level = 30,  max_cells = 8,  buffer = 0,  interior = FALSE,  radius = s2_earth_radius_meters(),  na.rm = FALSE)

Arguments

Matrix Functions

Description

These functions are similar to accessors and predicates, but instead ofrecyclingx andy to a common length and returning a vector of thatlength, these functions return a vector of lengthx with each elementi containing information about how the entire vectory relates tothe feature atx[i].

Usage

s2_closest_feature(x, y)s2_closest_edges(  x,  y,  k,  min_distance = -1,  max_distance = Inf,  radius = s2_earth_radius_meters())s2_farthest_feature(x, y)s2_distance_matrix(x, y, radius = s2_earth_radius_meters())s2_max_distance_matrix(x, y, radius = s2_earth_radius_meters())s2_contains_matrix(x, y, options = s2_options(model = "open"))s2_within_matrix(x, y, options = s2_options(model = "open"))s2_covers_matrix(x, y, options = s2_options(model = "closed"))s2_covered_by_matrix(x, y, options = s2_options(model = "closed"))s2_intersects_matrix(x, y, options = s2_options())s2_disjoint_matrix(x, y, options = s2_options())s2_equals_matrix(x, y, options = s2_options())s2_touches_matrix(x, y, options = s2_options())s2_dwithin_matrix(x, y, distance, radius = s2_earth_radius_meters())s2_may_intersect_matrix(x, y, max_edges_per_cell = 50, max_feature_cells = 4)

Arguments

Value

A vector of lengthx.

See Also

See pairwise predicate functions (e.g.,s2_intersects()).

Examples

city_names <- c("Vatican City", "San Marino", "Luxembourg")cities <- s2_data_cities(city_names)country_names <- s2_data_tbl_countries$namecountries <- s2_data_countries()# closest feature returns y indices of the closest feature# for each feature in xcountry_names[s2_closest_feature(cities, countries)]# farthest feature returns y indices of the farthest feature# for each feature in xcountry_names[s2_farthest_feature(cities, countries)]# use s2_closest_edges() to find the k-nearest neighboursnearest <- s2_closest_edges(cities, cities, k = 2, min_distance = 0)city_namescity_names[unlist(nearest)]# predicate matricescountry_names[s2_intersects_matrix(cities, countries)[[1]]]# distance matricess2_distance_matrix(cities, cities)s2_max_distance_matrix(cities, countries[1:4])

S2 Geography Predicates

Description

These functions operate two geography vectors (pairwise), and returna logical vector.

Usage

s2_contains(x, y, options = s2_options(model = "open"))s2_within(x, y, options = s2_options(model = "open"))s2_covered_by(x, y, options = s2_options(model = "closed"))s2_covers(x, y, options = s2_options(model = "closed"))s2_disjoint(x, y, options = s2_options())s2_intersects(x, y, options = s2_options())s2_equals(x, y, options = s2_options())s2_intersects_box(  x,  lng1,  lat1,  lng2,  lat2,  detail = 1000,  options = s2_options())s2_touches(x, y, options = s2_options())s2_dwithin(x, y, distance, radius = s2_earth_radius_meters())s2_prepared_dwithin(x, y, distance, radius = s2_earth_radius_meters())

Arguments

Model

The geometry model indicates whether or not a geometry includes its boundaries.Boundaries of line geometries are its end points.OPEN geometries do not contain their boundary (model = "open"); CLOSEDgeometries (model = "closed") contain their boundary; SEMI-OPEN geometries(model = "semi-open") contain half of their boundaries, such that when two polygonsdo not overlap or two lines do not cross, no point exist that belong tomore than one of the geometries. (This latter form, half-closed, isnot present in the OpenGIS "simple feature access" (SFA) standard nor DE9-IM onwhich that is based). The default values fors2_contains() (open)and covers/covered_by (closed) correspond to the SFA standard specificationof these operators.

See Also

Matrix versions of these predicates (e.g.,s2_intersects_matrix()).

BigQuery's geography function reference:

• ST_CONTAINS

• ST_COVEREDBY

• ST_COVERS

• ST_DISJOINT

• ST_EQUALS

• ST_INTERSECTS

• ST_INTERSECTSBOX

• ST_TOUCHES

• ST_WITHIN

• ST_DWITHIN

Examples

s2_contains(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"))s2_within(  c("POINT (5 5)", "POINT (-1 1)"),  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))")s2_covered_by(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"))s2_covers(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"))s2_disjoint(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"))s2_intersects(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"))s2_equals(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c(    "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",    "POLYGON ((10 0, 10 10, 0 10, 0 0, 10 0))",    "POLYGON ((-1 -1, 10 0, 10 10, 0 10, -1 -1))"  ))s2_intersects(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"))s2_intersects_box(  c("POINT (5 5)", "POINT (-1 1)"),  0, 0, 10, 10)s2_touches(  "POLYGON ((0 0, 0 1, 1 1, 0 0))",  c("POINT (0 0)", "POINT (0.5 0.75)", "POINT (0 0.5)"))s2_dwithin(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"),  0 # distance in meters)s2_dwithin(  "POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))",  c("POINT (5 5)", "POINT (-1 1)"),  1e6 # distance in meters)

Example Geometries

Description

These geometries are toy examples useful for testing various coordinateshuffling operations in the s2 package.

Usage

s2_data_example_wkt

Format

An object of classlist of length 29.

Low-resolution world boundaries, timezones, and cities

Description

Well-known binary versions of theNatural Earthlow-resolution world boundaries and timezone boundaries.

Usage

s2_data_tbl_countriess2_data_tbl_timezoness2_data_tbl_citiess2_data_countries(name = NULL)s2_data_timezones(utc_offset_min = NULL, utc_offset_max = utc_offset_min)s2_data_cities(name = NULL)

Arguments

Format

A data.frame with columnsname (character), andgeometry (wk_wkb)

An object of classdata.frame with 120 rows and 2 columns.

An object of classdata.frame with 243 rows and 3 columns.

Source

Natural Earth Data

Examples

head(s2_data_countries())s2_data_countries("Germany")s2_data_countries("Europe")head(s2_data_timezones())s2_data_timezones(-4)head(s2_data_cities())s2_data_cities("Cairo")

Earth Constants

Description

According to Yoder (1995), the radius of the earth is6371.01 km. These functions are used to set thedefault radis for functions that return a distanceor accept a distance as input(e.g.,s2_distance() ands2_dwithin()).

Usage

s2_earth_radius_meters()

References

Yoder, C.F. 1995. "Astrometric and Geodetic Properties of Earth and theSolar System" in Global Earth Physics, A Handbook of Physical Constants,AGU Reference Shelf 1, American Geophysical Union, Table 2.doi:10.1029/RF001p0001

Examples

s2_earth_radius_meters()

Create and Format Geography Vectors

Description

These functions create and exportgeography vectors.Unlike the BigQuery geography constructors, these functions do not sanitizeinvalid or redundant input usings2_union(). Note that when creating polygonsusings2_make_polygon(), rings can be open or closed.

Usage

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,  planar = FALSE,  tessellate_tol_m = s2_tessellate_tol_default())s2_geog_from_wkb(  wkb_bytes,  oriented = FALSE,  check = TRUE,  planar = FALSE,  tessellate_tol_m = s2_tessellate_tol_default())s2_as_text(  x,  precision = 16,  trim = TRUE,  planar = FALSE,  tessellate_tol_m = s2_tessellate_tol_default())s2_as_binary(  x,  endian = wk::wk_platform_endian(),  planar = FALSE,  tessellate_tol_m = s2_tessellate_tol_default())s2_tessellate_tol_default()

Arguments

See Also

Seeas_s2_geography() for other ways to construct geography vectors.

BigQuery's geography function reference:

• ST_GEOGPOINT

• ST_MAKELINE

• ST_MAKEPOLYGON

• ST_GEOGFROMTEXT

• ST_GEOGFROMWKB

• ST_ASTEXT

• ST_ASBINARY

Examples

# create point geographies using coordinate values:s2_geog_point(-64, 45)# create line geographies using coordinate values:s2_make_line(c(-64, 8), c(45, 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))# create polygon geographies using coordinate values:# (rings can be open or closed)s2_make_polygon(c(-45, 8, 0), c(64, 71, 90))# optionally, separate rings and/or features using# ring_id and/or feature_ids2_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))# import and export well-known text(geog <- s2_geog_from_text("POINT (-64 45)"))s2_as_text(geog)# import and export well-known binary(geog <- s2_geog_from_wkb(wk::as_wkb("POINT (-64 45)")))s2_as_binary(geog)# import geometry from planar spaces2_geog_from_text(   "POLYGON ((0 0, 1 0, 0 1, 0 0))",   planar = TRUE,   tessellate_tol_m = 1)# export geographies into planar spacegeog <- s2_make_polygon(c(179, -179, 179), c(10, 10, 11))s2_as_text(geog, planar = TRUE)# polygons containing a pole need an extra stepgeog <- s2_data_countries("Antarctica")geom <- s2_as_text(  s2_intersection(geog, s2_world_plate_carree()),  planar = TRUE)

S2 Geography Accessors

Description

Accessors extract information aboutgeography vectors.

Usage

s2_is_collection(x)s2_is_valid(x)s2_is_valid_detail(x)s2_dimension(x)s2_num_points(x)s2_is_empty(x)s2_area(x, radius = s2_earth_radius_meters())s2_length(x, radius = s2_earth_radius_meters())s2_perimeter(x, radius = s2_earth_radius_meters())s2_x(x)s2_y(x)s2_distance(x, y, radius = s2_earth_radius_meters())s2_max_distance(x, y, radius = s2_earth_radius_meters())

Arguments

See Also

BigQuery's geography function reference:

• ST_ISCOLLECTION

• ST_DIMENSION

• ST_NUMPOINTS

• ST_ISEMPTY

• ST_AREA

• ST_LENGTH

• ST_PERIMETER

• ST_X

• ST_Y

• ST_DISTANCE

• ST_MAXDISTANCE

Examples

# s2_is_collection() tests for multiple geometries in one features2_is_collection(c("POINT (-64 45)", "MULTIPOINT ((-64 45), (8 72))"))# s2_dimension() returns 0 for point, 1  for line, 2 for polygons2_dimension(  c(    "GEOMETRYCOLLECTION EMPTY",    "POINT (-64 45)",    "LINESTRING (-64 45, 8 72)",    "POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))",    "GEOMETRYCOLLECTION (POINT (-64 45), LINESTRING (-64 45, 8 72))"   ))# s2_num_points() counts pointss2_num_points(c("POINT (-64 45)", "LINESTRING (-64 45, 8 72)"))# s2_is_empty tests for emptinesss2_is_empty(c("POINT (-64 45)", "POINT EMPTY"))# calculate area, length, and perimeters2_area("POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))")s2_perimeter("POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))")s2_length(s2_boundary("POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))"))# extract x and y coordinates from pointss2_x(c("POINT (-64 45)", "POINT EMPTY"))s2_y(c("POINT (-64 45)", "POINT EMPTY"))# calculate minimum and maximum distance between two geometriess2_distance(  "POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))",  "POINT (-64 45)")s2_max_distance(  "POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))",  "POINT (-64 45)")

Create an S2 LngLat Vector

Description

This class represents a latitude and longitude on the Earth's surface.Most calculations in S2 convert this to aas_s2_point(), which is aunit vector representation of this value.

Usage

s2_lnglat(lng, lat)as_s2_lnglat(x, ...)## Default S3 method:as_s2_lnglat(x, ...)## S3 method for class 'wk_xy'as_s2_lnglat(x, ...)## S3 method for class 'wk_xyz'as_s2_lnglat(x, ...)

Arguments

Value

An object with class s2_lnglat

Examples

s2_lnglat(45, -64) # Halifax, Nova Scotia!as.data.frame(s2_lnglat(45, -64))

Geography Operation Options

Description

These functions specify defaults for options used to perform operationsand construct geometries. These are used in predicates (e.g.,s2_intersects()),and boolean operations (e.g.,s2_intersection()) to specify the model forcontainment and how new geometries should be constructed.

Usage

s2_options(  model = NULL,  snap = s2_snap_identity(),  snap_radius = -1,  duplicate_edges = FALSE,  edge_type = "directed",  validate = FALSE,  polyline_type = "path",  polyline_sibling_pairs = "keep",  simplify_edge_chains = FALSE,  split_crossing_edges = FALSE,  idempotent = FALSE,  dimensions = c("point", "polyline", "polygon"))s2_snap_identity()s2_snap_level(level)s2_snap_precision(precision)s2_snap_distance(distance)

Arguments

Model

The geometry model indicates whether or not a geometry includes its boundaries.Boundaries of line geometries are its end points.OPEN geometries do not contain their boundary (model = "open"); CLOSEDgeometries (model = "closed") contain their boundary; SEMI-OPEN geometries(model = "semi-open") contain half of their boundaries, such that when two polygonsdo not overlap or two lines do not cross, no point exist that belong tomore than one of the geometries. (This latter form, half-closed, isnot present in the OpenGIS "simple feature access" (SFA) standard nor DE9-IM onwhich that is based). The default values fors2_contains() (open)and covers/covered_by (closed) correspond to the SFA standard specificationof these operators.

Examples

# use s2_options() to specify containment models, snap level# layer creation options, and builder optionss2_options(model = "closed", snap = s2_snap_level(30))

Plot S2 Geographies

Description

Plot S2 Geographies

Usage

s2_plot(  x,  ...,  asp = 1,  xlab = "",  ylab = "",  rule = "evenodd",  add = FALSE,  plot_hemisphere = FALSE,  simplify = TRUE,  centre = NULL)

Arguments

Value

The input, invisibly

Examples

s2_plot(s2_data_countries())s2_plot(s2_data_cities(), add = TRUE)

Create an S2 Point Vector

Description

In S2 terminology, a "point" is a 3-dimensional unit vector representationof ans2_point(). Internally, all s2 objects are stored as3-dimensional unit vectors.

Usage

s2_point(x, y, z)s2_point_crs()as_s2_point(x, ...)## Default S3 method:as_s2_point(x, ...)## S3 method for class 'wk_xy'as_s2_point(x, ...)## S3 method for class 'wk_xyz'as_s2_point(x, ...)

Arguments

Value

An object with class s2_point

Examples

point <- s2_lnglat(-64, 45) # Halifax, Nova Scotia!as_s2_point(point)as.data.frame(as_s2_point(point))

Linear referencing

Description

Linear referencing

Usage

s2_project(x, y, radius = s2_earth_radius_meters())s2_project_normalized(x, y)s2_interpolate(x, distance, radius = s2_earth_radius_meters())s2_interpolate_normalized(x, distance_normalized)

Arguments

Value

• s2_interpolate() returns the point onx,distance metersalong the line.

• s2_interpolate_normalized() returns the point onx interpolatedto a fraction along the line.

• s2_project() returns thedistance thatpoint occurs alongx.

• s2_project_normalized() returns thedistance_normalized alongxwherepoint occurs.

Examples

s2_project_normalized("LINESTRING (0 0, 0 90)", "POINT (0 22.5)")s2_project("LINESTRING (0 0, 0 90)", "POINT (0 22.5)")s2_interpolate_normalized("LINESTRING (0 0, 0 90)", 0.25)s2_interpolate("LINESTRING (0 0, 0 90)", 2501890)

Low-level wk filters and handlers

Description

Low-level wk filters and handlers

Usage

## S3 method for class 's2_geography'wk_handle(  handleable,  handler,  ...,  s2_projection = s2_projection_plate_carree(),  s2_tessellate_tol = Inf)s2_geography_writer(  oriented = FALSE,  check = TRUE,  projection = s2_projection_plate_carree(),  tessellate_tol = Inf)## S3 method for class 's2_geography'wk_writer(handleable, ...)s2_trans_point()s2_trans_lnglat()s2_projection_plate_carree(x_scale = 180)s2_projection_mercator(x_scale = 20037508.3427892)s2_hemisphere(centre)s2_world_plate_carree(epsilon_east_west = 0, epsilon_north_south = 0)s2_projection_orthographic(centre = s2_lnglat(0, 0))

Arguments

Value

• s2_projection_plate_carree(),s2_projection_mercator(): An external pointerto an S2 projection.