Re: Re: Label vertices in Graph to display with

*To*: mathgroup at smc.vnet.net*Subject*: [mg87310] Re: [mg87276] Re: [mg87213] Label vertices in Graph to display with*From*: Murray Eisenberg <murray at math.umass.edu>*Date*: Mon, 7 Apr 2008 05:17:48 -0400 (EDT)*Organization*: Mathematics & Statistics, Univ. of Mass./Amherst*References*: <200804040758.CAA03960@smc.vnet.net> <200804061043.GAA14476@smc.vnet.net> <99B7896A-04FB-49CF-AC5F-67B9B7342875@lse.ac.uk>*Reply-to*: murray at math.umass.edu

The problem was, evidently, that the documentation you cite was too terse for me to discern quickly what I had to do. Perhaps ONE example showing how to use specified labels (not part of the original graph structure) would have helped -- a lot! J. McKenzie Alexander wrote: > What was the problem with the documentation? The documentation for > VertexRenderingFunction has the following as the first entry under "More > Information": > > VertexRenderingFunction->f specifies that each vertex should be rendered > with the graphics primitives given by f[rk,vk], where rk is the > coordinate position where the vertex is being placed, and vk is its name. > > > On 6 Apr 2008, at 11:43, Murray Eisenberg wrote: > >> At last I figured it out. (And no thanks to the documentation.) >> >> Here's a simple example of using non-default vertex labels in a >> GraphPlot display with a graph created by a GraphPlot function: >> >> <<Combinatorica` >> >> labels = {"a", "b", "c", "d"}; >> GraphPlot[Wheel[4], Method -> None, >> VertexRenderingFunction -> >> ({EdgeForm[{Brown}], Yellow, Disk[#1, 0.05], >> Black, Text[labels[[#2]], #1]} &), >> BaseStyle -> {FontSize -> 16}] >> >> The "secret" is in the meaning of the slot argument #2 to Text within >> the VertexRenderingFunction. >> >> Murray Eisenberg wrote: >>> I'm using some Combinatorica functions to create graphs where I do not >>> specify individually the vertices -- and hence do not individually >>> specify the vertex labels I want, e.g.: >>> >>> g = RotateVertices[Cycle[5], \[Pi]/10]; g = AddEdge[g, {2, 5}]; >>> g = SetGraphOptions[g, VertexLabel -> Characters["abcde"]]; >>> >>> If I use Combinatorica`ShowGraph, then I'll see the vertex labels: >>> >>> ShowGraph[g] >>> >>> However, if I use Mathematica 6's kernel function GraphPlot, I don't see >>> these individual labels, but rather the entire list {a,b,c,d,e} of >>> labels at each vertex! >>> >>> GraphPlot[g,Method->None,VertexRenderingFunction->(Text[#2,#1]&) >>> >>> How do I coerce GraphPlot to reproduce the behavior of ShowGraph, so >>> that it labels the individual vertices with a, b, c, d, e? >>> >>> (The interaction between Combintorica's graph-creating functions, on the >>> one hand, and GraphPlot, on the other hand, remains mysterious and >>> severely underdocumented for me. >>> >>> It seems there's a clear attempt to migrate display of graphs to the >>> kernel function GraphPlot and thereby discourage use of ShowGraph, yet >>> in almost everything I've attempted so far, GraphPlot does not so >>> readily or gracefully reproduce the functionality of Combinatorica'a >>> ShowGraph. This is most especially the case as it affects relative >>> newcomers to Mathematica like my students.) >> >> -- >> Murray Eisenberg murray at math.umass.edu >> Mathematics & Statistics Dept. >> Lederle Graduate Research Tower phone 413 549-1020 (H) >> University of Massachusetts 413 545-2859 (W) >> 710 North Pleasant Street fax 413 545-1801 >> Amherst, MA 01003-9305 >> > > > > Please access the attached hyperlink for an important electronic > communications disclaimer: > http://www.lse.ac.uk/collections/secretariat/legal/disclaimer.htm > -- Murray Eisenberg murray at math.umass.edu Mathematics & Statistics Dept. Lederle Graduate Research Tower phone 413 549-1020 (H) University of Massachusetts 413 545-2859 (W) 710 North Pleasant Street fax 413 545-1801 Amherst, MA 01003-9305

**References**:**Label vertices in Graph to display with GraphPlot***From:*Murray Eisenberg <murray@math.umass.edu>

**Re: Label vertices in Graph to display with GraphPlot***From:*Murray Eisenberg <murray@math.umass.edu>