Graph Theory

[:days4/projects/: Other SAGE Days 4 Project]

Participants: Emily Kirkman, Robert Miller, Craig Citro and David Roe

• (done) Latex Graphs: Craig Citro & Robert Miller -- write an eps file to be included in LaTeX documents.

• (done) NetworkX 1: Expose these in SAGE: centrality, cliques, cluster, cores, search.

  • Also note significant updates to Generators class from wrapping NetworkX, (see the [http://www.sagemath.org:9001/graph_generators wiki] for pretty pictures).

• Graph Database: Update interface to sqlite database of all graphs with 8 or fewer vertices.
  • Emily Kirkman is currently working on this.

• Electrical Networks, Jim Morrow's REU: Graphs with boundary are already in sage, but there are probably some useful constructions for Jim's summer REU that are not implemented yet. Especially data structures, perhaps an ElectricalNetworks class. Look at the Dirichlet problem, graphs on surfaces and (circular) planar embeddings of graphs.

• [http://sage.math.washington.edu/home/rlmill/wshlst.pdf Wishlist] from Chris Godsil: It would be great if we could complete the list this week.

• Bipartite Class
• NetworkX 2:
  • spectrum -- This should probably not be wrapped, but instead mimicked, since sage's linear algebra is undoubtedly faster.
  • hybrid, threshold -- Figure out what these are?
• NICE: The nauty clone for computing automorphism groups of graphs, and computing isomorphism. It has been converted to Pyrex, but it could still stand much optimization. Tabled, since Leon's programs will likely beat it out in spades.