TeX - LaTeX Stack Exchange is a question and answer site for users of TeX, LaTeX, ConTeXt, and related typesetting systems. It only takes a minute to sign up.
Sign up to join this community
I'm looking for some good examples of LaTeX code used to generate basic Cayley diagrams like this one:
Ideally, I'd like for the examples to make it fairly clear how to modify or remove various elements of the graph (labels, colors, line styles, etc.), and how to produce graphs for different basic groups.
TikZ should be pretty useful doing this. It's a package to 'draw' stuff in latex. I tried replicating your picture, there are still some rough edges, but it looks pretty nice I think.
\documentclass{article}
\usepackage{tikz}
\begin{document}
\usetikzlibrary{arrows,positioning}
\begin{tikzpicture} [%
nd/.style = {circle,fill=black,text=white,inner sep=1pt},
tn/.style = {node distance=1pt},
redarrow/.style={->, red, fill=none,>=stealth},
blueline/.style={-,blue,fill=none}]
\node[nd] (otl) at (0,0) {\sffamily F};
\node[nd] (itl) [below right=of otl] {\sffamily F};
\node[nd] (itr) [right=of itl] {\sffamily F};
\node[nd] (otr) [above right=of itr] {\sffamily F};
\node[nd] (ibl) [below=of itl] {\sffamily F};
\node[nd] (obl) [below left=of ibl] {\sffamily F};
\node[nd] (ibr) [right=of ibl] {\sffamily F};
\node[nd] (obr) [below right=of ibr] {\sffamily F};
\draw[redarrow] (otr) -- (otl);
\draw[redarrow] (otl) -- (obl);
\draw[redarrow] (obl) -- (obr);
\draw[redarrow] (obr) -- (otr);
\draw[redarrow] (itl) -- (itr);
\draw[redarrow] (itr) -- (ibr);
\draw[redarrow] (ibr) -- (ibl);
\draw[redarrow] (ibl) -- (itl);
\draw[blueline] (ibl) -- (obl);
\draw[blueline] (itl) -- (otl);
\draw[blueline] (ibr) -- (obr);
\draw[blueline] (itr) -- (otr);
\node[tn] [below right=of itl] {\tiny{$a$}};
\node[tn] [below left=of itr] {\tiny{$a^2$}};
\node[tn] [above left=of ibr] {\tiny{$a^3$}};
\node[tn] [above right=of ibl] {\tiny{$e$}};
\node[tn] [below left=of obl] {\tiny{$b$}};
\node[tn] [below=of obr] {\tiny{$ab=ba^3$}};
\node[tn] [above=of otl] {\tiny{$ba=a^3b$}};
\node[tn] [above=of otr] {\tiny{$a^2b=ba^2$}};
\end{tikzpicture}
\end{document}
which looks like
I would normally name the styles according to their uses, but since I have no idea what the diagram represents, I just named them according to their styles. The rotation is still missing, I'm trying to get that right though ;)
EDIT:
I got rotation etc. to work. Since the syntax is a little bit harder to read, I thought I would define a command for the nodes in the graph. I also fixed the text height for the 'captions', so that the ugly offset of the text is now gone. It's just the upper part that's changed, but in spirit of providing a MWE I also copied the rest of the code again:
\documentclass{article}
\usepackage{tikz}
\begin{document}
\usetikzlibrary{arrows,positioning}
\newcommand{\nd}[4]{\node[nd] (#1) #2 [label={[white,rotate=#3]center:{\sffamily #4}}] {}};
\begin{tikzpicture} [%
nd/.style = {circle,fill=black,text=white,inner sep=4pt},
tn/.style = {node distance=1pt,text height=0.5ex},
redarrow/.style={->, red, fill=none,>=stealth},
blueline/.style={-,blue,fill=none}]
\nd{otl}{at (0,0)}{0}{F};
\nd{itl}{[below right=of otl]}{270}{F};
\nd{itr}{[right=of itl]}{0}{F};
\nd{otr}{[above right=of itr]}{90}{x};
\nd{ibl}{[below=of itl]}{90}{F};
\nd{obl}{[below left=of ibl]}{0}{e};
\nd{ibr}{[right=of ibl]}{180}{F};
\nd{obr}{[below right=of ibr]}{90}{F};
\draw[redarrow] (otr) -- (otl);
\draw[redarrow] (otl) -- (obl);
\draw[redarrow] (obl) -- (obr);
\draw[redarrow] (obr) -- (otr);
\draw[redarrow] (itl) -- (itr);
\draw[redarrow] (itr) -- (ibr);
\draw[redarrow] (ibr) -- (ibl);
\draw[redarrow] (ibl) -- (itl);
\draw[blueline] (ibl) -- (obl);
\draw[blueline] (itl) -- (otl);
\draw[blueline] (ibr) -- (obr);
\draw[blueline] (itr) -- (otr);
\node[tn] [below right=of itl] {\tiny{$a$}};
\node[tn] [below left=of itr] {\tiny{$a^2$}};
\node[tn] [above left=of ibr] {\tiny{$a^3$}};
\node[tn] [above right=of ibl] {\tiny{$e$}};
\node[tn] [below left=of obl] {\tiny{$b$}};
\node[tn] [below=of obr] {\tiny{$ab=ba^3$}};
\node[tn] [above=of otl] {\tiny{$ba=a^3b$}};
\node[tn] [above=of otr] {\tiny{$a^2b=ba^2$}};
\end{tikzpicture}
\end{document}
petri library for this?
Experimenting (as a novice) with tikz and the petri library (whatever that is), I can use
\usepackage{tikz}
\usetikzlibrary{positioning}
\usetikzlibrary{petri}
\tikzset{state/.style={circle,draw=gray,inner sep=0pt,minimum size=7mm,label=center:$#1$,name=#1},
redarrow/.style={->, red, fill=none,>=stealth},bluearrow/.style={->, blue, fill=none,>=stealth},
redline/.style={-,red,fill=none},blueline/.style={-,blue,fill=none}}
\begin{tikzpicture}
\node[state=e]{};
\node[state=a,above=of e]{};
\node[state=a^2,right=of a]{};
\node[state=a^3,below=of a^2]{};
\node[state=b,below left=of e]{};
\node[state=ba^3,above left=of a]{};
\node[state=ba^2,above right=of a^2]{};
\node[state=ba,below right=of a^3]{};
\draw[redarrow](e)--(a);\draw[redarrow](b)--(ba);
\draw[redarrow](a)--(a^2);\draw[redarrow](ba)--(ba^2);
\draw[redarrow](a^2)--(a^3);\draw[redarrow](ba^2)--(ba^3);
\draw[redarrow](a^3)--(e);\draw[redarrow](ba^3)--(b);
\draw[blueline](e)--(b);
\draw[blueline](a)--(ba^3);
\draw[blueline](a^2)--(ba^2);
\draw[blueline](a^3)--(ba);
\end{tikzpicture}
to get this:
petri here. The only thing of petri you are using is [place], which you should be able to exchange against [circle,draw,inner sep=2pt] (I guessed the number). Then you pretty much arrive at my example
May 18, 2012 at 23:45
Here's an attempt in plain Metapost, using two of the built-in transformation commands: rotated t and reflectedabout(p,q).
prologues := 3;
outputtemplate := "%j%c.eps";
beginfig(1);
% define the image of the F to transform
s = 16;
picture f;
f = image(fill fullcircle scaled s; label("F" infont "cmss10" scaled 1.2,origin) withcolor white;);
% define the 8 points we need
% it's convenient to have the origin at the centre.
z1 = 50 right rotated -135;
z2 = z1 rotated -90;
z3 = z2 rotated -90;
z4 = z3 rotated -90;
z5 = 2z1;
z6 = 2z2;
z7 = 2z3;
z8 = 2z4;
% loop to draw the lines, arrows, and the F suitably transformed
% the cutbefore/cutafter parts shorten the arrows to avoid the discs
for i=0 upto 3:
draw z[i+1] -- z[5+i] withcolor blue;
n := (i+1) mod 4 + 1;
drawarrow z[i+1] -- z[n]
cutbefore fullcircle scaled s shifted z[i+1]
cutafter fullcircle scaled s shifted z[n]
withcolor red;
drawarrow z[n+4] -- z[i+5]
cutbefore fullcircle scaled s shifted z[n+4]
cutafter fullcircle scaled s shifted z[i+5]
withcolor red;
draw f rotated 90i shifted z[i+1];
draw f reflectedabout(up,down) rotated 90i shifted z[i+5];
endfor
% add suitable labels, carefully positioned.
label(btex $e$ etex, .7 z1);
label(btex $a$ etex, .7 z2);
label(btex $a^2$ etex, .7 z3);
label(btex $a^3$ etex, .7 z4);
label.bot(btex $b$ etex, z5-(0,s/2));
label.top(btex $ba=a^3b$ etex, z6+(0,s/2));
label.top(btex $ba^2=a^2b$ etex, z7+(0,s/2));
label.bot(btex $ba^3=ab$ etex, z8-(0,s/2));
endfig;
end.
