Create a wkpool from a vertex table and a segment table

The user-level constructor: give a vertex table and a segment table (as returned by pool_vertices() and pool_segments()) and get a wkpool back. It is a thin wrapper around new_wkpool(), which checks that every segment endpoint is a vertex id present in the pool.

Usage

wkpool(vertices, segments, paths = NULL, crs = NULL, geodesic = FALSE)

Arguments

vertices

A data.frame with columns .vx (integer vertex ids), x, y, and optionally z.

segments

A data.frame with integer columns .vx0 and .vx1 (vertex ids), and optionally .feature and .path.

paths

Optional data.frame describing the paths: columns .path, .feature, .part, .ring (as captured from wk::wk_coords() identifiers by establish_topology()).

crs

A CRS object (commonly an authority string such as "EPSG:4326"), carried but never interpreted, per wk's CRS propagation model. Use NULL for none, or wk::wk_crs_inherit().

geodesic

TRUE if segments should be interpreted as geodesics when coordinates are spherical, FALSE otherwise, NA to inherit.

Value

A wkpool object.

See also

new_wkpool() for the low-level constructor, establish_topology() to build a pool from wk geometry.

Examples

v <- data.frame(.vx = 1:4, x = c(0, 1, 1, 0), y = c(0, 0, 1, 1))
s <- data.frame(.vx0 = 1:4, .vx1 = c(2:4, 1L), .feature = 1L)
pool <- wkpool(v, s)
pool
#> <wkpool[4 segments, 4 vertices]>
#> [1] <segment: 1->2> <segment: 2->3> <segment: 3->4> <segment: 4->1>

# round trip through the accessors
wkpool(pool_vertices(pool), pool_segments(pool))
#> <wkpool[4 segments, 4 vertices]>
#> [1] <segment: 1->2> <segment: 2->3> <segment: 3->4> <segment: 4->1>