rewire#

Functions

`permute_node`(k, node, permutation)	Permute the endpoint indices of a node.
`pull_and_plug_endpoint`(k, source_endpoint, ...)	Pull out one endpoint and plug it somewhere else.
`replug_endpoint`(k, source_endpoint, ...)	Unplug an endpoint and overwrite the destination slot.
`swap_endpoints`(k, ep1, ep2)	Swap two endpoints in place (no insertion/removal).

pull_and_plug_endpoint(k, source_endpoint, destination_endpoint)#

Pull out one endpoint and plug it somewhere else.

This splits the source arc, creates a leaf at the destination, connects them, and removes temporary bivalent vertices. Operates in place.

Parameters:

k (PlanarDiagram | OrientedPlanarDiagram) – Diagram to modify.
source_endpoint (Endpoint | tuple) – Endpoint or (node, position) to pull out.
destination_endpoint (Endpoint | tuple) – Endpoint or (node, position) where it is plugged.

Return type:

None

replug_endpoint(k, source_endpoint, destination_endpoint)#

Unplug an endpoint and overwrite the destination slot.

Does not insert at the destination (overwrites). Operates in place.

Parameters:

k (PlanarDiagram | OrientedPlanarDiagram) – Diagram to modify.
source_endpoint (Endpoint | tuple) – Endpoint or (node, position) to unplug.
destination_endpoint (Endpoint | tuple) – Endpoint or (node, position) to overwrite.

Raises:

ValueError – If unplugging from a crossing (would create 3-valent crossing).

Return type:

None

swap_endpoints(k, ep1, ep2)#

Swap two endpoints in place (no insertion/removal).

Parameters:

Return type:

None

permute_node(k, node, permutation)#

Permute the endpoint indices of a node.

Example

permutation = {0: 0, 1: 2, 2: 3, 3: 1} maps [a, b, c, d] -> [a, d, b, c].

Parameters:

k (PlanarDiagram | OrientedPlanarDiagram) – Diagram to modify.
node – Node label.
permutation (dict | list | tuple) – Mapping or sequence giving new index for each old index.

Return type:

None