Hi Nathann, On Sat, Nov 28, 2009 at 1:57 AM, Nathann Cohen <nathann.co...@gmail.com> wrote:
<SNIP> > If I make no mistake, Robert Miller rewrote the Graph class in C, > which sounds like we are trying to remove networkX from Sage and use > our own version of graphs instead. If this is the case, we will have a > C class for graphs, meaning that some Graph functions will be written > in C instead of Python, thus gaining a lot of speed in Sage. At this > point, what should we do ? Rewrite the Python implementation of the > Floyd Marshall algorithm in C ( or whatever was written in NetworkX if > more efficient ), just call NetworkX, something different ? > > I think Sage's graph class needs to be rewritten to be a bit more > efficient..... Efficiency is a problem I have sometimes in Sage, on > instances for which this should not be a problem.... So I expect a lot > from the c_graphs that are currently somewhere in Sage ( are they used > ? How, when ? ) > > In the end : What is going on with the C graphs in Sage, can we expect > them to eb available soon ? What are we trying to do with NetworkX ( > leave it, keep it, nothing special ? ) I share some of your concerns as expressed above. In the last few days, I started writing an introductory chapter for a book on algorithmic graph theory using Sage. In doing so, I found that Sage lacks some basic features. For example, I have been unable to find a function/method to compute the degree sequence of a graph. What is required is a statement from Robert Miller, or people involved in the development of C graph, about the current state of C graph. The statement should include the state where C graph is at in terms of development, other things that need to be implemented, as well as how to navigate around the graph theory module. I was reading through graph.py only to discover that it's very, very long. Can that module be split up and organized along topical lines? I'm interested in helping out with developing Sage's graph theory module. That's a reason why I started writing the small book I mentioned above. In writing that book, I want to develop an understanding of the theory and algorithmic aspect of graph theory. And I plan to use that understanding to contribute to developing/maintaining the graph theory module. -- Regards Minh Van Nguyen -- 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
