subdivide_endpoint

subdivide_endpoint(k, endpoint, **attr)

Subdivide an endpoint by inserting a new 2-valent vertex on its incident arc.

The created node will have the given endpoint at position 0, and its twin at position 1 (via a call to subdivide_arc()).

Parameters:

• k (PlanarDiagram) – Planar diagram to modify (in place).

• endpoint (Endpoint | tuple) – An Endpoint instance or a pair (node, position).

• **attr – Extra attributes to apply to the newly created endpoints.

Returns:

The name of the newly created node.

Return type:

str