Hello, Well, this looks like a very interesting thing to add to sage. I am sure that the graph-guys around here would be enthousiastic, were it not for the summer vacations..
Could you open a ticket on trac for that ? and prepare and upload a patch ? Do you need help to do that ? http://trac.sagemath.org Or maybe you can first work with the sage-combinat branch, if you prefer. That's a good way to prepare something for insertion into sage. http://wiki.sagemath.org/combinat Cheers, Frederic Le jeudi 26 juillet 2012 02:14:41 UTC+2, Keeler Russell a écrit : > > Hello everyone, > > I've been working on a function to calculate the chromatic symmetric > function (a.k.a. CSF) of a graph as part of a related research project. You > can find the code here: https://github.com/keeler/csf (the files are > csf.py and csf.pyx, in particular). I wanted to know if this function would > be useful to anyone, and would greatly appreciate any tips regarding how to > improve its performance. > > Notes on the algorithm: I use Thm 2.5 from Stanley's "A Symmetric > Function Generalization of the Chromatic Polynomial of a Graph" to > calculate the CSF. This is pretty directly reflected in the code in csf.py. > However, csf.pyx uses a bit more machinery. First of all, it stores the > coefficients of the corresponding power-sum symmetric function terms in a > dictionary of speedy access. Second, I represent the elements in each edge > set with a bitset (1 for included, 0 for excluded). Third, I use Gray Codes > to either add or delete a single edge for each iteration. > > If you have any questions for me, or would like me to provide more > comments in my code (which I may just do anyway), please feel free to ask > me. > > Thank you, > -- Keeler > -- You received this message because you are subscribed to the Google Groups "sage-combinat-devel" group. To view this discussion on the web visit https://groups.google.com/d/msg/sage-combinat-devel/-/wCurZ3wLUHkJ. To post to this group, send email to sage-combinat-devel@googlegroups.com. To unsubscribe from this group, send email to sage-combinat-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sage-combinat-devel?hl=en.
