ARC model
Arcs are unique paths that connect nodes. In a polygon layer with shared boundaries, the arcs are the linear features that have no branches.
ARC(x, ...) ## Default S3 method: ARC(x, ...) ## S3 method for class 'PATH' ARC(x, ...)
x |
input model |
... |
arguments passed to methods |
Nodes are the vertices where three or more arcs meet. An arc can exist without including any nodes, a path that has no neighbouring relationship with another path.
This is not the same terminology as used by other systems, such as "arc-node". The
arc_link_vertex mapping is inherently ordered, but we don't consider order of arcs.
Duplicated arcs (i.e. complementary turns around neighbouring polygons) are not kept.
The object_link_arc mapping records which arc belongs to the objects, so feature polygons
can in theory be reconstructed within objects by tracing arc_link_vertex start and end point
identity.
ARC model
a <- ARC(minimal_mesh) sc_arc(a) sc_arc(minimal_mesh)
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