Package 'geos'

Title: Open Source Geometry Engine ('GEOS') R API
Description: Provides an R API to the Open Source Geometry Engine ('GEOS') library (<https://libgeos.org/>) and a vector format with which to efficiently store 'GEOS' geometries. High-performance functions to extract information from, calculate relationships between, and transform geometries are provided. Finally, facilities to import and export geometry vectors to other spatial formats are provided.
Authors: Dewey Dunnington [aut, cre] , Edzer Pebesma [aut]
Maintainer: Dewey Dunnington <[email protected]>
License: MIT + file LICENSE
Version: 0.2.4.9000
Built: 2024-08-30 02:50:26 UTC
Source: https://github.com/paleolimbot/geos

Help Index

Create GEOS Geometry Vectors

Description

Create GEOS Geometry Vectors

Usage

## S3 method for class 'wk_xy'
as_geos_geometry(x, ...)

## S3 method for class 'wk_xyz'
as_geos_geometry(x, ...)

as_geos_geometry(x, ...)

## S3 method for class 'geos_geometry'
as_geos_geometry(x, ...)

## Default S3 method:
as_geos_geometry(x, ...)

## S3 method for class 'character'
as_geos_geometry(x, ..., crs = NULL)

## S3 method for class 'blob'
as_geos_geometry(x, ..., crs = NULL)

## S3 method for class 'WKB'
as_geos_geometry(x, ..., crs = NULL)

geos_geometry(crs = wk::wk_crs_inherit())

Arguments

x

An object to be coerced to a geometry vector
...

Unused
crs

An object that can be interpreted as a CRS. See wk::wk_crs().

Value

A geos geometry vector

Examples

as_geos_geometry("LINESTRING (0 1, 3 9)")

Extract information from a GEOS geometry

Description

Note that geos_x(), geos_y(), and geos_z() do not handle empty points (use geos_write_xy() if you need to handle this case). Similarly, the min/max functions will error on empty geometries.

Usage

geos_area(geom)

geos_length(geom)

geos_x(geom)

geos_y(geom)

geos_z(geom)

geos_xmin(geom)

geos_ymin(geom)

geos_xmax(geom)

geos_ymax(geom)

geos_minimum_clearance(geom)

geos_is_empty(geom)

geos_is_simple(geom)

geos_is_ring(geom)

geos_has_z(geom)

geos_is_closed(geom)

geos_type_id(geom)

geos_type(geom)

geos_precision(geom)

geos_srid(geom)

geos_num_coordinates(geom)

geos_num_geometries(geom)

geos_num_interior_rings(geom)

geos_num_rings(geom)

geos_dimension(geom)

geos_coordinate_dimension(geom)

geos_is_clockwise(geom)

geos_hilbert_code(geom, extent = wk::wk_bbox(geom), level = 15)

Arguments

geom

A GEOS geometry vector
extent

A geometry describing the extent of geom within which Hilbert codes should be computed. Defaults to wk::wk_bbox() of geom.
level

The Hilbert level of precision (between 0 and 15).

Value

A vector of length geom

Examples

geos_area("POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))")
geos_length("POLYGON ((0 0, 10 0, 10 10, 0 10, 0 0))")
geos_x("POINT Z (1 2 3)")
geos_y("POINT Z (1 2 3)")
geos_z("POINT Z (1 2 3)")
geos_xmin("LINESTRING (0 1, 2 3)")
geos_ymin("LINESTRING (0 1, 2 3)")
geos_xmax("LINESTRING (0 1, 2 3)")
geos_ymax("LINESTRING (0 1, 2 3)")
geos_minimum_clearance("POLYGON ((0 0, 10 0, 10 10, 3 5, 0 10, 0 0))")

geos_is_empty(c("POINT EMPTY", "POINT (0 1)"))
geos_is_simple(c("LINESTRING (0 0, 1 1)", "LINESTRING (0 0, 1 1, 1 0, 0 1)"))
geos_is_ring(
  c(
    "LINESTRING (0 0, 1 0, 1 1, 0 1, 0 0)",
    "LINESTRING (0 0, 1 0, 1 1, 0 1)"
   )
)
geos_is_closed(
  c(
    "LINESTRING (0 0, 1 0, 1 1, 0 1, 0 0)",
    "LINESTRING (0 0, 1 0, 1 1, 0 1)"
   )
)
geos_has_z(c("POINT Z (1 2 3)", "POINT (1 2)"))

geos_type_id(c("POINT (0 0)", "LINESTRING (0 0, 1 1)"))
geos_srid(wk::as_wkb(c("SRID=1234;POINT (0 0)", "POINT (0 0)")))
geos_num_coordinates(c("POINT (0 0)", "MULTIPOINT (0 0, 1 1)"))
geos_num_geometries(c("POINT (0 0)", "MULTIPOINT (0 0, 1 1)"))
geos_num_interior_rings("POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))")
geos_dimension(c("POINT (0 0)", "LINESTRING (0 0, 1 1)"))
geos_coordinate_dimension(c("POINT (0 0)", "POINT Z (0 0 1)"))

Create a basic GEOS STRTree

Description

An experimental alternative to the geos_strtree() that provides a more flexible interface and potentially faster spatial joins. Notably, geos_basic_strtree_insert() uses wk::wk_envelope() instead of as_geos_geometry() and does not keep the underlying geometry in memory. For object types like wk::xy() with an optimized wk::wk_envelope() method, this is very efficient.

Usage

geos_basic_strtree(items = NULL, node_capacity = 10L)

geos_basic_strtree_size(tree)

geos_basic_strtree_finalized(tree)

geos_basic_strtree_insert(tree, items)

geos_basic_strtree_query(tree, query, limit = NA, fill = FALSE)

geos_basic_strtree_query_filtered(
  tree,
  query,
  tree_geom,
  fun,
  ...,
  .chunk_size = 65536
)

Arguments

items

Items to add to the tree index
node_capacity

The maximum number of child nodes that a node may have. The minimum recommended capacity value is 4. If unsure, use a default node capacity of 10.
tree

A geos_basic_strtree()
query

Items with which to query the tree
limit

The maximum number of matches in the tree to return
fill

If TRUE, always returns limit matches per item in query padded with NA if fewer than limit matches are found.
tree_geom

A vctr coercible to geos_geometry() whose indices align with tree.
fun

A vectorized binary predicate (e.g. geos_intersects()) that will be called with the tree geometry, the query geometry and any ... args passed.
...

Passed to fun.
.chunk_size

The approximate number of comparisons to pass to fun.

Value

A geos_basic_strtree object

Examples

tree <- geos_basic_strtree(wk::xy(1:5, 1:5))
geos_basic_strtree_size(tree)
(geos_basic_strtree_insert(tree, wk::xy(6:10, 6:10)))
geos_basic_strtree_query(tree, as_geos_geometry("LINESTRING (3 0, 0 3)"))

Buffer a geometry

Description

Usage

geos_buffer(geom, distance, params = geos_buffer_params())

geos_offset_curve(geom, distance, params = geos_buffer_params())

geos_buffer_params(
  quad_segs = 30,
  end_cap_style = c("round", "flat", "square"),
  join_style = c("round", "mitre", "bevel"),
  mitre_limit = 1,
  single_sided = FALSE
)

Arguments

geom

A GEOS geometry vector
distance

The buffer distance. Can be negative to buffer or offset on the righthand side of the geometry.
params

A geos_buffer_params()
quad_segs

The number of segments per quadrant. A higher number here will increase the apparent resolution of the resulting polygon.
end_cap_style

One of "round", "flat", or "square".
join_style

One of "round", "mitre", or "bevel".
mitre_limit

If join_style is "mitre", the relative extent (from zero to one) of the join.
single_sided

Use TRUE to buffer on only the right side of the geometry. This does not apply to geos_offset_curve(), which is always one-sided.

Value

A GEOS geometry vector along the recycled length of geom and distance.

Examples

geos_buffer("POINT (0 0)", 1)
geos_offset_curve("LINESTRING (0 0, 0 10, 10 0)", 1)

Geometry transformers

Description

Geometry transformers

Usage

geos_centroid(geom)

geos_boundary(geom)

geos_minimum_width(geom)

geos_minimum_clearance_line(geom)

geos_minimum_rotated_rectangle(geom)

geos_unary_union(geom)

geos_unary_union_prec(geom, grid_size)

geos_coverage_union(geom)

geos_point_on_surface(geom)

geos_node(geom)

geos_make_valid(geom, make_valid_params = geos_make_valid_params())

geos_make_valid_params(
  keep_collapsed = TRUE,
  method = c("make_valid_linework", "make_valid_structure")
)

geos_unique_points(geom)

geos_reverse(geom)

geos_merge_lines(geom)

geos_build_area(geom)

geos_envelope(geom)

geos_envelope_rct(geom)

geos_extent(geom)

geos_convex_hull(geom)

geos_concave_hull(geom, ratio, allow_holes = FALSE)

geos_concave_hull_of_polygons(
  geom,
  ratio,
  is_tight = TRUE,
  allow_holes = FALSE
)

geos_polygon_hull_simplify(
  geom,
  ratio,
  hull_type = c("outer", "inner"),
  ratio_mode = c("vertex", "area")
)

geos_point_start(geom)

geos_point_end(geom)

geos_line_merge(geom)

geos_line_merge_directed(geom)

geos_transform_xy(geom, trans)

geos_clone(geom)

geos_set_srid(geom, srid)

geos_point_n(geom, index)

geos_simplify(geom, tolerance)

geos_remove_repeated_points(geom, tolerance)

geos_simplify_preserve_topology(geom, tolerance)

geos_set_precision(
  geom,
  grid_size,
  preserve_topology = TRUE,
  keep_collapsed = FALSE
)

geos_normalize(geom)

geos_densify(geom, tolerance)

geos_clip_by_rect(geom, rect)

Arguments

geom

A GEOS geometry vector
grid_size

For ⁠_prec()⁠ variants, the grid size such that all vertices of the resulting geometry will lie on the grid.
make_valid_params

A geos_make_valid_params() object.
keep_collapsed

Should items that become EMPTY due to rounding be kept in the output?
method

The method to use for geos_make_valid(). One of:

  • "make_valid_linework" combines all rings into a set of noded lines and then extracts valid polygons from that linework.

  • "make_valid_structure" Structured method, first makes all rings valid then merges shells and subtracts holes from shells to generate valid result. Assumes that holes and shells are correctly categorized.

ratio

The normalized ratio between the shape of the concave hull and the area of the return value. Use 1 for the convex hull; use 0 for maximum concave-ness.
allow_holes

Use TRUE to allow the concave hull to contain holes
is_tight

Use FALSE to allow concave hull to expand beyond the convex hull.
hull_type

One of "outer" or "inner".
ratio_mode

One of "vertex" or "area", describing the normalized proportion type for which ratio represents.
trans

A wk transform object.
srid

An integer spatial reference identifier.
index

The index of the point or geometry to extract.
tolerance

A minimum distance to use for simplification or densification. Use a higher value for more simplification (or less densification).
preserve_topology

Should topology internal to each feature be preserved?
rect

A list() representing rectangles in the form list(xmin, ymin, xmax, ymax). List items with length 1 will be recycled to the length of the longest item.

Value

A GEOS geometry vector of length geom

Examples

geos_centroid(c("POINT (0 1)", "LINESTRING (0 0, 1 1)"))
geos_boundary(c("POLYGON ((0 0, 1 0, 0 1, 0 0))", "LINESTRING (0 0, 1 1)"))
geos_minimum_width("POLYGON ((0 0, 1 0, 0 1, 0 0))")
geos_minimum_clearance_line("POLYGON ((0 0, 10 0, 10 10, 3 5, 0 10, 0 0))")
geos_minimum_rotated_rectangle("POLYGON ((0 0, 1 0, 0.5 0.5, 0 0))")
geos_minimum_bounding_circle("LINESTRING (-1 -1, 1 1)")
geos_unary_union("MULTIPOINT (0 1, 0 1)")
geos_point_on_surface("LINESTRING (0 1, 0.2 3, 10 10)")
geos_node("POLYGON ((0 0, 1 0, 0 1, 0 0))")
geos_make_valid("POLYGON ((0 0, 1 1, 1 0, 0 1, 0 0))")
geos_unique_points("POLYGON ((0 0, 1 0, 0 1, 0 0))")
geos_reverse("LINESTRING (0 0, 1 1)")
geos_merge_lines(
  "MULTILINESTRING ((0 0, 0.5 0.5, 2 2), (0.5 0.5, 2 2))"
)
geos_build_area("LINESTRING (0 0, 1 0, 0 1, 0 0)")
geos_envelope("LINESTRING (0 0, 1 2)")
geos_convex_hull("MULTIPOINT (0 0, 1 0, 0 2, 0 0)")
geos_point_start("LINESTRING (0 0, 1 1)")
geos_point_end("LINESTRING (0 0, 1 1)")

geos_simplify("LINESTRING (0 0, 0 1, 0 2)", 0.1)
geos_simplify_preserve_topology("LINESTRING (0 0, 0 1, 0 2)", 0.1)

Create rectangles from bounds

Description

Create rectangles from bounds

Usage

geos_create_rectangle(xmin, ymin, xmax, ymax, crs = NULL)

Arguments

xmin

Left bound of envelope
ymin

Lower bound of envelope
xmax

Right bound of envelope
ymax

Upper bound of envelope
crs

An object that can be interpreted as a CRS. See wk::wk_crs().

Value

A geos_geometry() consisting of a polygon

Delaunay triagulations and Voronoi diagrams

Description

These functions return one triangulation/diagram per feature as a multi geometry. These functions are not vectorized along their parameters.

Usage

geos_delaunay_triangles(geom, tolerance = 0)

geos_constrained_delaunay_triangles(geom)

geos_delaunay_edges(geom, tolerance = 0)

geos_voronoi_polygons(geom, env = NULL, tolerance = 0)

geos_voronoi_edges(geom, env = NULL, tolerance = 0)

Arguments

geom

A GEOS geometry vector whose nodes will be used as input.
tolerance

A snapping tolerance or 0 to disable snapping
env

A boundary for the diagram, or NULL to construct one based on the input

Value

A GEOS geometry vector of length geom

Examples

geos_delaunay_triangles("MULTIPOINT (0 0, 1 0, 0 1)")
geos_delaunay_edges("MULTIPOINT (0 0, 1 0, 0 1)")

geos_voronoi_polygons("MULTIPOINT (0 0, 1 0, 0 1)")
geos_voronoi_edges("MULTIPOINT (0 0, 1 0, 0 1)")

Binary predicates

Description

Binary predicates

Usage

geos_disjoint(geom1, geom2)

geos_touches(geom1, geom2)

geos_intersects(geom1, geom2)

geos_crosses(geom1, geom2)

geos_within(geom1, geom2)

geos_contains(geom1, geom2)

geos_overlaps(geom1, geom2)

geos_equals(geom1, geom2)

geos_equals_exact(geom1, geom2, tolerance = .Machine$double.eps^2)

geos_covers(geom1, geom2)

geos_covered_by(geom1, geom2)

geos_prepared_disjoint(geom1, geom2)

geos_prepared_touches(geom1, geom2)

geos_prepared_intersects(geom1, geom2)

geos_prepared_crosses(geom1, geom2)

geos_prepared_within(geom1, geom2)

geos_prepared_contains(geom1, geom2)

geos_prepared_contains_properly(geom1, geom2)

geos_prepared_overlaps(geom1, geom2)

geos_prepared_covers(geom1, geom2)

geos_prepared_covered_by(geom1, geom2)

Arguments

geom1, geom2

GEOS geometry vectors, recycled to a common length.
tolerance

The maximum separation of vertices that should be considered equal.

Value

A logical vector along the recycled length of geom1 and geom2

Matrix predicates

Description

Matrix predicates

Usage

geos_disjoint_matrix(geom, tree)

geos_touches_matrix(geom, tree)

geos_intersects_matrix(geom, tree)

geos_crosses_matrix(geom, tree)

geos_within_matrix(geom, tree)

geos_contains_matrix(geom, tree)

geos_contains_properly_matrix(geom, tree)

geos_overlaps_matrix(geom, tree)

geos_equals_matrix(geom, tree)

geos_equals_exact_matrix(geom, tree, tolerance = .Machine$double.eps^2)

geos_covers_matrix(geom, tree)

geos_covered_by_matrix(geom, tree)

geos_disjoint_any(geom, tree)

geos_touches_any(geom, tree)

geos_intersects_any(geom, tree)

geos_crosses_any(geom, tree)

geos_within_any(geom, tree)

geos_contains_any(geom, tree)

geos_contains_properly_any(geom, tree)

geos_overlaps_any(geom, tree)

geos_equals_any(geom, tree)

geos_equals_exact_any(geom, tree, tolerance = .Machine$double.eps^2)

geos_covers_any(geom, tree)

geos_covered_by_any(geom, tree)

Arguments

geom

A GEOS geometry vector
tree

A geos_strtree()
tolerance

The maximum separation of vertices that should be considered equal.

Value

A list() of integer vectors containing the indices of tree for which the predicate would return TRUE.

Distance calculations

Description

Distance calculations

Usage

geos_distance(geom1, geom2)

geos_prepared_distance(geom1, geom2)

geos_distance_indexed(geom1, geom2)

geos_distance_hausdorff(geom1, geom2, densify = NULL)

geos_distance_frechet(geom1, geom2, densify = NULL)

geos_is_within_distance(geom1, geom2, distance)

geos_prepared_is_within_distance(geom1, geom2, distance)

Arguments

geom1, geom2

GEOS geometry vectors, recycled to a common length.
densify

A fraction between 0 and 1 denoting the degree to which edges should be subdivided (smaller value means more subdivisions). Use NULL to calculate the distance as-is.
distance

A threshold distance, below which geos_is_within_distance() and geos_prepared_is_within_distance() will return TRUE.

Value

A numeric vector along the recycled length of geom1 and geom2

Create empty geometries

Description

Create empty geometries

Usage

geos_empty(type_id = "geometrycollection", crs = wk::wk_crs_inherit())

as_geos_type_id(type_id)

## Default S3 method:
as_geos_type_id(type_id)

## S3 method for class 'character'
as_geos_type_id(type_id)

## S3 method for class 'numeric'
as_geos_type_id(type_id)

Arguments

type_id

The numeric type identifier for which an empty should be returned, an object from which one can be extracted using as_geos_type_id() (default to calling geos_type_id()). This is most usefully a character vector with the geometry type (e.g., point, linestring, polygon).
crs

An object that can be interpreted as a CRS. See wk::wk_crs().

Value

A GEOS geometry vector.

Examples

geos_empty(c("point", "linestring", "polygon"))
geos_empty(1:7)
geos_empty(geos_read_wkt(c("POINT (0 1)", "LINESTRING (0 0, 1 1)")))

Access child geometries

Description

Access child geometries

Usage

geos_geometry_n(geom, n)

geos_ring_n(geom, n)

Arguments

geom

A GEOS geometry vector
n

The (one-based) index of the child geometry

Value

A GEOS geometry vector along the recycled length of geom and i.

Examples

multipoint <- "MULTIPOINT (0 0, 1 1, 2 2)"
geos_geometry_n(multipoint, seq_len(geos_num_geometries(multipoint)))

poly <- "POLYGON ((0 0, 0 1, 1 0, 0 0), (0.1 0.1, 0.1 0.2, 0.2 0.1, 0.1 0.1))"
geos_ring_n(poly, seq_len(geos_num_rings(poly)))

Generate inner join keys based on a GEOS predicate

Description

Experimental low-level spatial join infrastructure based on the geos_basic_strtree().

Usage

geos_inner_join(
  x,
  y,
  predicate = "intersects",
  distance = NA,
  suffix = c(".x", ".y")
)

geos_inner_join_keys(x, y, predicate = "intersects", distance = NA)

Arguments

x, y

Geometry vectors with a wk::wk_handle() method.
predicate

One of:

  • intersects

  • contains

  • contains_properly

  • covered_by

  • covers

  • crosses

  • equals

  • equals_exact

  • intersects

  • within_distance

  • overlaps

  • touches

distance

Passed to geos_is_within_distance() when predicate is "within_distance"; passed to geos_equals_exact() when predicate is "equals_exact.
suffix

A character vector of length 2 with suffixes for the left and right sides for output columns with duplicated names.

Value

A data.frame with columns x and y corresponding to the 1-based indices on pairs of x and y for which predicate is TRUE.

Examples

x <- data.frame(
  col_x = "a",
  geometry = as_geos_geometry("POINT (10 10)")
)

y <- data.frame(
  col_y = "a",
  geometry = as_geos_geometry("POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))")
)

geos_inner_join(x, y, "intersects")

geos_inner_join_keys(
  "POINT (5 5)",
  "POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))",
  "intersects"
)

Binary geometry operators

Description

  • geos_intersection() returns the set of points common to both x and y.

  • geos_difference() returns the set of points from x that are not contained by y.

  • geos_sym_difference() returns the set of points that are not common to x and y.

  • geos_union() returns the set of points contained by either x or y.

  • geos_shared_paths() returns a GEOMETRYCOLLECTION containing two MULTILINESTRINGS: the first containing paths in the same direction, the second containing common paths in the opposite direction.

  • geos_snap() snaps the vertices of x within tolerance of y to y.

Usage

geos_intersection(geom1, geom2)

geos_difference(geom1, geom2)

geos_sym_difference(geom1, geom2)

geos_union(geom1, geom2)

geos_intersection_prec(geom1, geom2, grid_size)

geos_difference_prec(geom1, geom2, grid_size)

geos_sym_difference_prec(geom1, geom2, grid_size)

geos_union_prec(geom1, geom2, grid_size)

geos_shared_paths(geom1, geom2)

geos_snap(geom1, geom2, tolerance = .Machine$double.eps^2)

geos_clearance_line_between(geom1, geom2, prepare = FALSE)

Arguments

geom1, geom2

GEOS geometry vectors, recycled to a common length.
grid_size

For ⁠_prec()⁠ variants, the grid size such that all vertices of the resulting geometry will lie on the grid.
tolerance

The maximum separation of vertices that should be considered equal.
prepare

Use prepared geometries to calculate clearance line

Value

A GEOS geometry vector along the recycled length of geom1 and geom2.

Examples

poly1 <- "POLYGON ((0 0, 0 10, 10 10, 10 0, 0 0))"
poly2 <- "POLYGON ((5 5, 5 15, 15 15, 15 5, 5 5))"

geos_intersection(poly1, poly2)
geos_difference(poly1, poly2)
geos_sym_difference(poly1, poly2)
geos_union(poly1, poly2)

line <- "LINESTRING (11 0, 11 10)"
geos_snap(poly1, line, tolerance = 2)

geos_shared_paths("LINESTRING (0 0, 1 1, 2 2)", "LINESTRING (3 3, 2 2, 1 1)")

Geometry validity

Description

Usage

geos_is_valid(geom)

geos_is_valid_detail(geom, allow_self_touching_ring_forming_hole = FALSE)

Arguments

geom

A GEOS geometry vector
allow_self_touching_ring_forming_hole

It's all in the name

Examples

geos_is_valid(
  c(
    "POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))",
    "POLYGON ((0 0, 1 1, 1 0, 0 1, 0 0))"
  )
)

geos_is_valid_detail(
  c(
    "POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))",
    "POLYGON ((0 0, 1 1, 1 0, 0 1, 0 0))"
  )
)

Circular approximations

Description

Circular approximations

Usage

geos_largest_empty_circle_spec(geom, boundary, tolerance)

geos_largest_empty_crc(geom, boundary, tolerance)

geos_minimum_bounding_circle(geom)

geos_minimum_bounding_crc(geom)

geos_maximum_inscribed_circle_spec(geom, tolerance)

geos_maximum_inscribed_crc(geom, tolerance)

Arguments

geom

A GEOS geometry vector
boundary

An outer boundary for the largest empty circle algorithm.
tolerance

Threshold for considering circles to be touching a boundary.

Create geometries from vectors of coordinates

Description

These functions transform raw coordinates into point, line, polygon, features, or nest a vector of geometries into a MULTI* type or GEOMETRYCOLLECTION. See wk::wk_coords(), geos_unnest(), or wk::wk_flatten() to perform inverse operations; see wk::xy(), wk::wk_linestring(), wk::wk_polygon(), or wk::wk_collection() for generic versions that work with non-GEOS types.

Usage

geos_make_point(x, y, z = NA_real_, crs = NULL)

geos_make_linestring(x, y, z = NA_real_, feature_id = 1L, crs = NULL)

geos_make_polygon(
  x,
  y,
  z = NA_real_,
  feature_id = 1L,
  ring_id = 1L,
  crs = NULL
)

geos_make_collection(geom, type_id = "geometrycollection", feature_id = 1L)

Arguments

x, y, z

Vectors of coordinate values
crs

An object that can be interpreted as a CRS. See wk::wk_crs().
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.
geom

A GEOS geometry vector
type_id

The numeric type identifier for which an empty should be returned, an object from which one can be extracted using as_geos_type_id() (default to calling geos_type_id()). This is most usefully a character vector with the geometry type (e.g., point, linestring, polygon).

Value

A GEOS geometry vector

Examples

geos_make_point(1:3, 1:3)
geos_make_linestring(1:3, 1:3)
geos_make_polygon(c(0, 1, 0), c(0, 0, 1))
geos_make_collection("POINT (1 1)")

Find the closest feature

Description

Finds the closest item index in tree to geom, vectorized along geom.

Usage

geos_nearest(geom, tree)

geos_nearest_indexed(geom, tree)

geos_nearest_hausdorff(geom, tree, densify = NULL)

geos_nearest_frechet(geom, tree, densify = NULL)

Arguments

geom

A GEOS geometry vector
tree

A geos_strtree()
densify

A fraction between 0 and 1 denoting the degree to which edges should be subdivided (smaller value means more subdivisions). Use NULL to calculate the distance as-is.

Value

An integer vector of length geom containing the index of tree that is closest to each feature in geom.

Create polygons from noded edges

Description

Create polygons from noded edges

Usage

geos_polygonize(collection)

geos_polygonize_valid(collection)

geos_polygonize_cut_edges(collection)

geos_polygonize_full(collection)

Arguments

collection

A GEOMETRYCOLLECTION or MULTILINESTRING of edges that meet at their endpoints.

Value

A GEOMETRYCOLLECTION of polygons

Examples

geos_polygonize("MULTILINESTRING ((0 0, 0 1), (0 1, 1 0), (1 0, 0 0))")
geos_polygonize_valid("MULTILINESTRING ((0 0, 0 1), (0 1, 1 0), (1 0, 0 0))")
geos_polygonize_cut_edges("MULTILINESTRING ((0 0, 0 1), (0 1, 1 0), (1 0, 0 0))")

Linear referencing

Description

  • geos_project() and geos_project_normalized() return the distance of point geom2 projected on geom1 from the origin of geom1, which must be a lineal geometry.

  • geos_interpolate() performs an inverse operation, returning the point along geom representing the given distance from the origin along the geometry.

  • ⁠_normalized()⁠ variants use a distance normalized to the geos_length() of the geometry.

Usage

geos_project(geom1, geom2)

geos_project_normalized(geom1, geom2)

geos_interpolate(geom, distance)

geos_interpolate_normalized(geom, distance_normalized)

Arguments

geom1, geom2

GEOS geometry vectors, recycled to a common length.
geom

A GEOS geometry vector
distance

Distance along the linestring to interpolate
distance_normalized

Distance along the linestring to interpolate relative to the length of the linestring.

Examples

geos_interpolate("LINESTRING (0 0, 1 1)", 1)
geos_interpolate_normalized("LINESTRING (0 0, 1 1)", 1)

geos_project("LINESTRING (0 0, 10 10)", "POINT (5 5)")
geos_project_normalized("LINESTRING (0 0, 10 10)", "POINT (5 5)")

Read and write well-known text

Description

Read and write well-known text

Usage

geos_read_wkt(wkt, fix_structure = FALSE, crs = NULL)

geos_write_wkt(geom, include_z = TRUE, precision = 16, trim = TRUE)

geos_read_geojson(geojson, crs = NULL)

geos_write_geojson(geom, indent = -1)

geos_read_wkb(wkb, fix_structure = FALSE, crs = NULL)

geos_write_wkb(
  geom,
  include_z = TRUE,
  include_srid = FALSE,
  endian = 1,
  flavor = c("extended", "iso")
)

geos_read_hex(hex, fix_structure = FALSE, crs = NULL)

geos_write_hex(
  geom,
  include_z = TRUE,
  include_srid = FALSE,
  endian = 1,
  flavor = c("extended", "iso")
)

geos_read_xy(point)

geos_write_xy(geom)

Arguments

wkt

a character() vector of well-known text
fix_structure

Set the reader to automatically repair structural errors in the input (currently just unclosed rings) while reading.
crs

An object that can be interpreted as a CRS. See wk::wk_crs().
geom

A GEOS geometry vector
include_z, include_srid

Include the values of the Z and M coordinates and/or SRID in the output? Use FALSE to omit, TRUE to include, or NA to include only if present. Note that using TRUE may result in an error if there is no value present in the original.
precision

The number of significant digits to include iin WKT output.
trim

Trim unnecessary zeroes in the output?
geojson

A character() vector fo GeoJSON features
indent

The number of spaces to use when indenting a formatted version of the output. Use -1 to indicate no formatting.
wkb

A list() of raw() vectors (or NULL representing an NA value).
endian

0 for big endian or 1 for little endian.
flavor

One of "extended" (i.e., EWKB) or "iso".
hex

A hexidecimal representation of well-known binary
point

A list() representing points in the form list(x, y).

Examples

geos_read_wkt("POINT (30 10)")
geos_write_wkt(geos_read_wkt("POINT (30 10)"))

Dimensionally extended 9 intersection model

Description

See the Wikipedia entry on DE-9IM for how to interpret pattern, match, and the result of geos_relate() and/or geos_relate_pattern_create().

Usage

geos_relate(geom1, geom2, boundary_node_rule = "mod2")

geos_relate_pattern(geom1, geom2, pattern, boundary_node_rule = "mod2")

geos_relate_pattern_match(match, pattern)

geos_relate_pattern_create(
  II = "*",
  IB = "*",
  IE = "*",
  BI = "*",
  BB = "*",
  BE = "*",
  EI = "*",
  EB = "*",
  EE = "*"
)

Arguments

geom1, geom2

GEOS geometry vectors, recycled to a common length.
boundary_node_rule

One of "mod2", "endpoint", "multivalent_endpoint", or "monovalent_endpoint".
pattern, match

A character vector representing the match
II, IB, IE, BI, BB, BE, EI, EB, EE

One of "0", "1", "2", "T", "F", or "*" describing the dimension of the intersection between the interior (I), boundary (B), and exterior (E).

Examples

geos_relate_pattern_match("FF*FF1***", c(NA, "FF*FF****", "FF*FF***F"))
geos_relate("POINT (0 0)", "POINT (0 0)")
geos_relate_pattern("POINT (0 0)", "POINT (0 0)", "T********")
geos_relate_pattern_create(II = "T")

Segment operations

Description

Segment operations

Usage

geos_segment_intersection(a, b)

geos_orientation_index(a, point)

Arguments

a, b

A list() representing segments in the form list(x0, y0, x1, y1). List items with length 1 will be recycled to the length of the longest item.
point

A list() representing points in the form list(x, y).

Value

geos_segment_intersection() returns a list(x, y); geos_orientation_index() returns -1, 0 or 1, depending if the point lies to the right of (-1), is colinear with (0) or lies to the left of (1) the segment (as judged from the start of the segment looking towards the end).

Examples

geos_segment_intersection(
  list(0, 0, 10, 10),
  list(10, 0, 0, 10)
)

geos_orientation_index(
  list(0, 0, 10, 10),
  list(15, c(12, 15, 17))
)

Create a GEOS STRTree

Description

Create a GEOS STRTree

Usage

geos_strtree(geom, node_capacity = 10L)

geos_strtree_query(tree, geom)

geos_strtree_data(tree)

as_geos_strtree(x, ...)

## Default S3 method:
as_geos_strtree(x, ...)

## S3 method for class 'geos_strtree'
as_geos_strtree(x, ...)

## S3 method for class 'geos_geometry'
as_geos_strtree(x, ...)

Arguments

geom

A GEOS geometry vector
node_capacity

The maximum number of child nodes that a node may have. The minimum recommended capacity value is 4. If unsure, use a default node capacity of 10.
tree

A geos_strtree()
x

An object to convert to a geos_strtree()
...

Unused

Value

A geos_str_tree object

Unnest nested geometries

Description

Ths function flattens nested geometries (i.e., multi or geometrycollection types) into a vector with the same or fewer levels of nesting. See geos_geometry_n() to access individual geometries within a collection; see wk::wk_flatten() for a version of this function that works with non-GEOS geometries; see geos_make_collection() and wk::wk_collection() for functions that perform the inverse operation.

Usage

geos_unnest(geom, keep_empty = FALSE, keep_multi = TRUE, max_depth = 1)

Arguments

geom

A GEOS geometry vector
keep_empty

If TRUE, EMPTY geomtries are left as-is rather than collapsing to length 0.
keep_multi

If TRUE, MULTI* geometries are not expanded to sub-features (i.e., only GEOMETRYCOLLECTIONs are).
max_depth

The maximum recursive GEOMETRYCOLLECTION depth to unnest.

Value

A GEOS geometry vector, with a length greater than or equal to geom with an attribute "lengths" that can be used to map elements of the result to the original item.

Examples

geos_unnest("GEOMETRYCOLLECTION (POINT (1 2), POINT (3 4))")

GEOS version information

Description

GEOS version information

Usage

geos_version(runtime = TRUE)

Arguments

runtime

Use FALSE to return the build-time GEOS version, which may be different than the runtime version if a different version of the libgeos package was used to build this package.

Examples

geos_version()
geos_version(runtime = FALSE)

# check for a minimum version of GEOS
geos_version() >= "3.8.1"

Plot GEOS geometries

Description

Plot GEOS geometries

Usage

## S3 method for class 'geos_geometry'
plot(
  x,
  ...,
  asp = 1,
  bbox = NULL,
  xlab = "",
  ylab = "",
  rule = "evenodd",
  add = FALSE,
  simplify = 1,
  crop = TRUE
)

Arguments

x

A GEOS geometry vector
...

Passed to plotting functions for features: graphics::points() for point and multipoint geometries, graphics::lines() for linestring and multilinestring geometries, and graphics::polypath() for polygon and multipolygon geometries.
asp, xlab, ylab

Passed to graphics::plot()
bbox

The limits of the plot as a rct() or compatible object
rule

The rule to use for filling polygons (see graphics::polypath())
add

Should a new plot be created, or should handleable be added to the existing plot?
simplify

A relative tolerance to use for simplification of geometries. Use 0 to disable simplification; use a higher number to make simplification coarser.
crop

Use TRUE to crop the input to the extent of the plot.

Value

The input, invisibly

Examples

plot(as_geos_geometry("LINESTRING (0 0, 1 1)"))
plot(as_geos_geometry("POINT (0.5 0.4)"), add = TRUE)

Vctrs methods

Description

Vctrs methods

Usage

vec_cast.geos_geometry(x, to, ...)

vec_ptype2.geos_geometry(x, y, ...)

Arguments

x, y, to, ...

See vctrs::vec_cast() and vctrs::vec_ptype2().

Compatibility with the wk package

Description

Compatibility with the wk package

Usage

## S3 method for class 'geos_geometry'
wk_handle(handleable, handler, ...)

geos_geometry_writer()

## S3 method for class 'geos_geometry'
wk_writer(handleable, ...)

Arguments

handleable

A geometry vector (e.g., wkb(), wkt(), xy(), rct(), or sf::st_sfc()) for which wk_handle() is defined.
handler

A wk_handler object.
...

Passed to the wk_handle() method.

Value

The result of the handler

Examples

library(wk)
wk_handle(as_geos_geometry("POINT (1 2)"), wk::wkt_writer())