Differences between revisions 26 and 45 (spanning 19 versions)
 ⇤ ← Revision 26 as of 2007-06-14 10:27:58 → Size: 1405 Editor: c-67-183-18-7 Comment: ← Revision 45 as of 2008-11-14 13:41:54 → ⇥ Size: 2392 Editor: localhost Comment: converted to 1.6 markup Deletions are marked like this. Additions are marked like this. Line 3: Line 3: [:days4/projects/: Other SAGE Days 4 Project] [[days4/projects/| Other SAGE Days 4 Project]] Line 6: Line 6: {{{# Cayley Graph of \$A_5\$sage: G = sage.groups.perm_gps.permgroup.AlternatingGroup(5)sage: C = G.cayley_graph()sage: C.show3d(vertex_size=0.01, arc_size=0.005, arc_size2=0.008, xres=1000, yres=800)}}}== BEFORE =={{attachment:before.png}}== AFTER =={{attachment:after.png}}== NEW ==Vertex and edge colors for 3d graphs{{attachment:dod.png}}{{attachment:pet.png}} Line 10: Line 23: * Also note significant updates to Generators class from wrapping NetworkX, (see the [[http://www.sagemath.org:9001/graph_generators|wiki]] for pretty pictures). * [[http://sage.math.washington.edu/home/rlmill/wshlst.pdf|Wishlist]] from Chris Godsil. Most feasible first.    * (done) graph isomorphism and automorphism, graph6 and sparse6 formatting, database of small graphs, eigenvalues and eigenspaces, characteristic and minimal polynomials, cayley graphs, edge colorings    * (easy) bipartite graphs, point graph, line graph, graph from set and binary function, vertices as vector subspaces, generating trees    * (medium) certain types of curves for plotting edges, generator based on geng    * (tedium) databases: ted spence, gordon royle    * (hard) max indep. set, chromatic number, hamilton cycles and paths, chromatic polynomial, tutte polynomial, cut vertices, vertex/edge connectivity, planarity * Graph Database: Update interface to sqlite database of all graphs with 8 or fewer vertices.    * Emily Kirkman is currently working on this. Line 13: Line 42: * Graph Database: Update interface to sqlite database of all graphs with 8 or fewer vertices. * [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 * Bipartite Class Line 22: Line 47: * 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.

# Graph Theory

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

```# Cayley Graph of \$A_5\$
sage: G = sage.groups.perm_gps.permgroup.AlternatingGroup(5)
sage: C = G.cayley_graph()
sage: C.show3d(vertex_size=0.01, arc_size=0.005, arc_size2=0.008, xres=1000, yres=800)```

## NEW

Vertex and edge colors for 3d graphs

• (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 wiki for pretty pictures).

• Wishlist from Chris Godsil. Most feasible first.

• (done) graph isomorphism and automorphism, graph6 and sparse6 formatting, database of small graphs, eigenvalues and eigenspaces, characteristic and minimal polynomials, cayley graphs, edge colorings
• (easy) bipartite graphs, point graph, line graph, graph from set and binary function, vertices as vector subspaces, generating trees
• (medium) certain types of curves for plotting edges, generator based on geng
• (tedium) databases: ted spence, gordon royle
• (hard) max indep. set, chromatic number, hamilton cycles and paths, chromatic polynomial, tutte polynomial, cut vertices, vertex/edge connectivity, planarity
• 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.

• 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?

days4/projects/graphs (last edited 2008-11-14 13:41:54 by localhost)