On Wed, 25 Apr 2018, Ewan Davies wrote:
The Moser spindle is important as a small (7 vertex) unit distance graph that is not 3-colorable, and is included in sage's smallgraphs.py. But the embedding given there is not the unit distance embedding! I think this should be corrected, and have appropriate code.
Maybe. OTOH also the Petersen graph is unit distance graph, but it already has a nice drawing. A graph may have several different "nice" properties such that a single drawing can not show them all.
Secondly, the Golomb graph is another small unit distance graph which is not 3-colorable. I would like to submit a function for smallgraphs.py that lets this be a named graph in sage.
Good idea, but first check that it is not already included with some other name.
You may also want to add a function to recognize unit distance graphs. -- Jori Mäntysalo
