Nth Problem with TikZ and Extensive Form Games

Question

I'd like to typset the tree on the left of the image. Unfortunately, TikZ seems way to complicated to me... I tried with this code, without success

\documentclass{beamer}
\usepackage{tikz} % Game theory packages
\usetikzlibrary{calc}

% Node styles
\tikzset{
% Two node styles for game trees: solid and hollow
solid node/.style={circle,draw,inner sep=1.5,fill=black},
hollow node/.style={circle,draw,inner sep=1.5}
}

\begin{document}

\begin{frame}
    \begin{tikzpicture}[scale=0.7,font=\footnotesize]
        % Specify spacing for each level of the tree
            \tikzstyle{level 1}=[level distance=18mm,sibling distance=27mm]
            \tikzstyle{level 2}=[level distance=18mm,sibling distance=27mm]
        % The Tree
        \node(0)[hollow node,label=above:{$1$}]{}
            child{node(1)[solid node, label=above:{$2$}]{}
                child{node(0-1-1)[solid node, label=above:{$1$}]{} edge from parent node[left]{$E$}}
                child{node(0-1-2)[label=below:{$(3,1)$}]{} edge from parent node[right]{$F$}}                                   
                    child{node(0-1-1-1)[label=below:{$(1,2)$}]{} edge from parent node[right]{$G$}} % The error is here
                edge from parent node[left,xshift=-3]{$C$}          
        }
            child{node(2)[label=below:{$(0,3)$}]{} edge from parent node[right, xshift=3]{$D$}
            };

        \end{tikzpicture}
\end{frame}
\end{document}

I'd like also to ask you if something easier for game theory than Tikz exists for trees.

Answer 1

Note that there is a package, istgame, which specializes on game trees. For general trees, forest is a very powerful tool. It allows you to draw your tree very easily.

\documentclass{article}
\usepackage{forest}
\forestset{el/.style={edge label={node [pos=0.7,above,outer sep=3pt] {$#1$} }}}
\begin{document}
\begin{forest}
for tree={circle,fill,inner sep=1pt,calign=fixed edge angles}
[,label=above:1
 [,label=above left:2,el=A
  [,label=above left:1,el=C
   [,label=below:{0,2},el=E ]
   [,label=below:{2,0},el=F ]
  ]
  [,label=below:{1,1},el=D]
 ]
 [,label=below:{3,3},el=B]
]
\end{forest}
\end{document}

Answer 2

My plain TikZ code is a bit long but easy to read.

\documentclass{article}
%\documentclass{beamer}
\usepackage{tikz}
\begin{document}
%\begin{frame}  
\begin{center}
\begin{tikzpicture}[scale=1,
h/.style={circle,draw=magenta,thick,inner sep=1.5},
s/.style={h,fill=magenta}]
\path
(0,0)     node[h] (1)  {} node[above] {1}  
+(1,-1)   node[s] (2b) {} node[below] {3,3}
++(-1,-1) node[s] (2a) {} node[left]  {2}  
+(1,-1)   node[s] (3b) {} node[below] {1,1}
++(-1,-1) node[s] (3a) {} node[left]  {1}  
+(1,-1)   node[s] (4b) {} node[below] {0,2}
+(-1,-1)  node[s] (4a) {} node[below] {2,0};

\draw (1)
--(2a) node[pos=.4,left]{A}
--(3a) node[pos=.4,left]{C}
--(4a) node[pos=.4,left]{E}
(1)--(2b)  node[pos=.4,right]{B}
(2a)--(3b) node[pos=.4,right]{D}
(3a)--(4b) node[pos=.4,right]{F};

\newcommand{\putcolumn}[6]{%
\path #1 node{#2} 
++(-90:1)  node{#3} ++(-90:1) node{#4}
++(-90:1)  node{#5} ++(-90:1) node{#6};
}%
\begin{scope}[shift={(4,0)}]
\draw (0,0) grid (2,-4);
\putcolumn{(.5,.5)}{C}{2,0}{0,2}{3,3}{3,3}
\putcolumn{(1.5,.5)}{D}{1,1}{1,1}{3,3}{3,3}
\putcolumn{(-.5,.5)}{}{AE}{AF}{BE}{BF}
\end{scope}
\end{tikzpicture}
\end{center}
%\end{frame}    
\end{document}

Answer 3

I propose this short code with pstricks – more specifically pst-tree:

\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{fourier}
\usepackage{pst-tree}
\usepackage{auto-pst-pdf}

\begin{document}

\begin{pspicture}
\psset{tnsep=1pt, labelsep=3pt}
\pstree[nodesep=0pt, levelsep=1.5cm, treesep=3cm]{\Tc{2pt}~[ tnpos=a, tnsep=-1pt]{1}} {
        \pstree{\Tdot\nbput{$ A $} \uput[ul](\pssucc){$ 2 $}} {%
                \pstree{\Tdot \nbput{$ C $} \uput[ul](\pssucc){{1}}}{%
                        \pstree{\Tdot \nbput{$ E $} \uput[ul](\pssucc){{2}}}{}%
                        \Tdot\naput{$F$}\uput[d](\pssucc){$0,2$}}%
        \Tdot_{$D$} \uput[d](\pssucc){$1,1$}}%
\Tdot_{$B$} \uput[d](\pssucc){$3,3$}}
    \end{pspicture}%

 \end{document}

Answer 4

How to use the istgame package:

(You only need to briefly read three pages (pp.6-8) of the manual to do this.)

\documentclass{standalone}

\usepackage{istgame}

\begin{document}

\begin{istgame}
\xtShowEndPoints
\xtdistance{10mm}{20mm}
\istroot(0)[initial node]{1}
  \istb{A}[al]       \istb{B}[ar]{3,3}  \endist
\istroot(1)(0-1)<135>{2}
  \istb{C}[al]       \istb{D}[ar]{1,1}  \endist
\istroot(2)(1-1)<135>{1}
  \istb{E}[al]{2,0}  \istb{F}[ar]{0,2}  \endist
\end{istgame}

\end{document}

Answer 5

My attempt with tikz-qtree, but I did not find out how to fix the angles:

\usepackage{tikz-qtree}

\tikzset{grow'=down}

\begin{document}
    \begin{standalone}
        \begin{tikzpicture}[level distance=30pt,
                            sibling distance=10pt,
                            every tree node/.style={draw,circle,inner sep=0pt,minimum size=3pt},
                            edge from parent path={(\tikzparentnode) -- (\tikzchildnode)},
                            ]
            \Tree   [. \node[label=above:1] {}; 
                        \edge node[auto=left,pos=.6] {$B$};
                            [. \node[fill=black,label=below:{3,3}] {}; ]
                        \edge node[auto=right,pos=.6] {$A$};
                            [.\node[fill=black,label=above left:2] {}; 
                                \edge node[auto=left,pos=.6] {$D$};
                                    [.\node[fill=black,label=below:{1,1}] {}; ]
                                \edge node[auto=right,pos=.6] {$C$};
                                [.\node[fill=black,label=above left:1] {}; 
                                \edge node[auto=left,pos=.6] {$F$};
                                    [.\node[fill=black,label=below:{2,2}] {}; ]
                                \edge node[auto=right,pos=.6] {$E$};
                                    [.\node[fill=black,label=above left:2] {}; ] 
                                ]
                            ]
                    ]     
        \end{tikzpicture}   
    \end{standalone}
\end{document}