s2: s2_closest_feature – R documentation

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s2_closest_feature

Matrix Functions

Description

These functions are similar to accessors and predicates, but instead of recycling x and y to a common length and returning a vector of that length, these functions return a vector of length x with each element i containing information about how the entire vector y relates to the feature at x[i].

Usage

s2_closest_feature(x, y)

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

`x, y`	Geography vectors, coerced using `as_s2_geography()`. `x` is considered the source, where as `y` is considered the target.
`radius`	Radius of the earth. Defaults to the average radius of the earth in meters as defined by `s2_earth_radius_meters()`.
`options`	An `s2_options()` object describing the polygon/polyline model to use and the snap level.
`distance`	A distance on the surface of the earth in the same units as `radius`.
`max_edges_per_cell`	For `s2_may_intersect_matrix()`, this values controls the nature of the index on `y`, with higher values leading to coarser index. Values should be between 10 and 50; the default of 50 is adequate for most use cases, but for specialized operations users may wish to use a lower value to increase performance.
`max_feature_cells`	For `s2_may_intersect_matrix()`, this value controls the approximation of `x` used to identify potential intersections on `y`. The default value of 4 gives the best performance for most operations, but for specialized operations users may wish to use a higher value to increase performance.

Value

A vector of length x.

Examples

city_names <- c("Vatican City", "San Marino", "Luxembourg")
cities <- s2_data_cities(city_names)
country_names <- s2_data_tbl_countries$name
countries <- s2_data_countries()

# closest feature returns y indices of the closest feature
# for each feature in x
country_names[s2_closest_feature(cities, countries)]

# farthest feature returns y indices of the farthest feature
# for each feature in x
country_names[s2_farthest_feature(cities, countries)]

# predicate matrices
country_names[s2_intersects_matrix(cities, countries)[[1]]]

# distance matrices
s2_distance_matrix(cities, cities)
s2_max_distance_matrix(cities, countries[1:4])

s2

Spherical Geometry Operators Using the S2 Geometry Library

v1.0.4

Apache License (== 2.0)

Authors

Dewey Dunnington [aut] (<https://orcid.org/0000-0002-9415-4582>), Edzer Pebesma [aut, cre] (<https://orcid.org/0000-0001-8049-7069>), Ege Rubak [aut], Jeroen Ooms [ctb] (configure script), Google, Inc. [cph] (Original s2geometry.io source code)

Initial release