\newpage\section{Pappus} %<––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––> %<––––––––––––––––––––––––––––– Pappus ––––––––––––––––––––––––––––––––> %<––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––––> \begin{NewMacroBox}{grPappus}{\oarg{options}} \medskip From MathWord : \url{http://mathworld.wolfram.com/PappusGraph.html} \emph{A cubic symmetric distance-regular graph on 18 vertices, illustrated below in three embeddings. It can be represented in LCF notation $[5,7,-7,7,-7,-5]^3$ (Frucht 1976).} \href{http://mathworld.wolfram.com/topics/GraphTheory.html}% {\textcolor{blue}{MathWorld}} by \href{http://en.wikipedia.org/wiki/Eric_W._Weisstein}% {\textcolor{blue}{E.Weisstein}} From Wikipedia : \url{http://en.wikipedia.org/wiki/Pappus_graph} \emph{In the mathematical field of graph theory, the Pappus graph is a 3-regular graph with 18 vertices and 27 edges, formed as the Levi graph of the Pappus configuration. It is a distance-regular graph, one of only 14 such cubic graphs according to Cubic symmetric graphs.} This macro can be used with three different forms. \end{NewMacroBox} \bigskip \subsection{\tkzname{Pappus Graph : form 1}} \begin{center} \begin{tkzexample}[vbox] \begin{tikzpicture}[scale=.7] \GraphInit[vstyle=Art] \grPappus[RA=7] \end{tikzpicture} \end{tkzexample} \end{center} \vfill\newpage \subsection{\tkzname{Pappus Graph : form 2}} \begin{center} \begin{tkzexample}[vbox] \begin{tikzpicture} \GraphInit[vstyle=Art] \SetGraphArtColor{red}{olive} \grPappus[form=2,RA=7,RB=5,RC=3] \end{tikzpicture} \end{tkzexample} \end{center} \vfill\newpage \subsection{\tkzname{Pappus Graph : form 3}} \begin{center} \begin{tkzexample}[vbox] \begin{tikzpicture} \GraphInit[vstyle=Art] \SetGraphArtColor{gray}{blue} \grPappus[form=3,RA=7,RB=5,RC=2.5] \end{tikzpicture} \end{tkzexample} \end{center} \endinput