Utilities

Some useful miscellaneous components.

AUTHORS:

• Matthew Henderson (2010-12-30): initial version

grange(vtc_colouring)

The colours used by a colouring (vertex-to-color map).

independence_number(graph)

Compute the independence number of ‘graph’.

inverse(vtc_colouring, colour)

The vertices where a colour appears in a vertex-to-colour map.

support(list_assignment, nodes, colour)

A list of those vertices in ‘nodes’ which have ‘colour’ in the list associated with that vertex by ‘list_assignment’.

support_subgraph(graph, list_assignment, colour)

The subgraph induced by those vertices of ‘graph’ which have ‘colour’ in the list associated by ‘list_assignment’.

vtc_to_ctv(vtc)

Translate a verticex-to-colour map into a colour-to-vertices map.