The chromatic index of multigraphs

[Peleg Michaeli]

Hi,

Is there any way to calculate the chromatic number of multigraphs in sage?

The method `graph_coloring.edge_coloring` raises

ValueError: This method is not known to work on graphs with multiedges. Perhaps this method can be updated to handle them, but in the meantime if you want to use it please disallow multiedges using allow_multiple_edges()

Thanks,
Peleg.

[Dima Pasechnik]

On Friday, March 10, 2017 at 9:59:14 AM UTC, Peleg Michaeli wrote:

Hi,

Is there any way to calculate the chromatic number of multigraphs in sage?

you mean edge colouring, right?

I presumed you can construct the edge (line_graph()) graph, colour vertices, pull the colours back,

but constructing line_graph in this case also does not work.

(Although fixing it should be trivial)