On Sat, Feb 27, 2010 at 2:41 PM, Rob Beezer <goo...@beezer.cotse.net> wrote: > On Feb 27, 6:37 am, David Joyner <wdjoy...@gmail.com> wrote: >> There are several places where bipartite graphs >> differ (at least in the literature) from regular graphs. >> For example, usually the bipartite graph's adjacency matrix >> is not square. > > I think an "adjacency matrix" should always be square. But for a > bipartite graph if you order the vertices consecutively within the two > parts of the bipartition, then you get a block matrix with zero > matrices in the northwest and southeast corners. And the other two > corners are transposes of each other (but not square when the > bipartite sets are different sizes). > > This is in the BipartiteGraph class as "reduced_adjacency_matrix()." > I can't recall ever seeing this matrix given a name, so I don't know > if this is how one would expect to find it. In the research for your > graph theory book have you learned what others call it?
I have now seen three other terms (besides the admittedly sloppy "adjacency matrix") for this: transfer matrix, biadjacency matrix, and reduced adjacency matrix. > > Rob > > -- > To post to this group, send an email to sage-devel@googlegroups.com > To unsubscribe from this group, send an email to > sage-devel+unsubscr...@googlegroups.com > For more options, visit this group at > http://groups.google.com/group/sage-devel > URL: http://www.sagemath.org > -- To post to this group, send an email to sage-devel@googlegroups.com To unsubscribe from this group, send an email to sage-devel+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/sage-devel URL: http://www.sagemath.org
