Re: Graphtheory package questions
- To: mathgroup at smc.vnet.net
- Subject: [mg35955] Re: [mg35918] Graphtheory package questions
- From: Rob Pratt <rpratt at email.unc.edu>
- Date: Fri, 9 Aug 2002 05:18:03 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
On Thu, 8 Aug 2002, Oliver Friedrich wrote: > Hallo, > > I'm running 3.0. > > I want to do a document about network analysis of electrical networks by > means of that things like method of node potentials and method of mesh > currents, OK? > Now I think that the DiscreteMath'Combinatorica package provides some nice > features to generate, show and operate with graphs. > > I want to generate a graph out of a given netlist (almost SPICE format) and > display that graph. The vertices would be the nodes of the circuit, the > edges would be the components of the circuit. > > 1. I didn't find a suitable embedding of a circuit graph. It would be nice > to generate an embedding which would avoid any intersections of edges if > possible. In my case it is possible, because my circuit diagram doesn't have > any crossings of lines. Is there an automatic embedding doing that or do I > have to generate my vertices list by hand? > > 2. All the graphs shown in the package help don't have any vertices or edges > named with a reference. You can imagine, it's not useful to show a graph of > a circuit, where neither the components references nor the node references > are shown. Is there way to give the vertices a name and display that name in > the graph? The same for the edges. > > 3. I couldn' find that book of Steven Skiena anymore. Is there any > documentation on that package beside the Online help and that book? > > Thanks for your help and especially greetings to David Park, my inquiry > sounds like it has to do with your drawing package ;-) > > Oliver Friedrich There is an updated version of Combinatorica available at www.combinatorica.com. Some of the commands require Mathematica 4.0, though. 1. There is no command to automatically generate a plane embedding of a planar graph, although a result of Wagner (1936) and Fary (1948) states that every planar graph has a straight-line embedding. However, there is a command, PlanarQ, that determines whether a graph is planar or not. 2. The new Combinatorica includes numerous labeling options. 3. Skiena's book is out of print, but Cambridge University Press is publishing a new version. Rob Pratt Department of Operations Research The University of North Carolina at Chapel Hill rpratt at email.unc.edu http://www.unc.edu/~rpratt/