Find shared edges between features

Find shared edges between features

Usage

find_shared_edges(x)

Arguments

x

A wkpool (ideally after merge_coincident)

Value

Data frame of edges shared by multiple features

Details

After merging coincident vertices, edges that were duplicated across features (e.g., shared polygon boundaries) will reference the same vertex pair. This function finds them and reports which features share each edge.

Examples

x <- wk::as_wkb(c(
  "POLYGON ((0 0, 1 0, 1 1, 0 1, 0 0))",
  "POLYGON ((1 0, 2 0, 2 1, 1 1, 1 0))"
))
pool <- establish_topology(x)
merged <- merge_coincident(pool)
find_shared_edges(merged)
#>   edge_key .vx0 .vx1 .feature segment_idx features
#> 2      2-3    2    3        1           2     1, 2
#> 8      2-3    2    3        2           8     1, 2