在图表边缘创建标签

Question

我想在树的边缘添加标签 3、4、5，就像您在图片上看到的那样，但我不知道如何做 :(

我的最小例子：

    \documentclass{article}
    \usepackage[T1]{fontenc}
    \usepackage{tikz}
    \usepackage{tikz-qtree}

    \usetikzlibrary{positioning}
    \usetikzlibrary{trees}

    \begin{document}

    \begin{center}
    \begin{tikzpicture}[sibling distance=40pt]
    \tikzset{edge from parent/.style=
    {draw,
    edge from parent path={(\tikzparentnode.south)
    -- +(0,-8pt)
    -| (\tikzchildnode)}}}
    \Tree [.\textrm{} [.$x_2=1$  ]
              [.$x_2\neq1$ [.$x_2=2$ ]
                           [.$x_2\neq2$ [.$x_2=3$ ]
                                        [.$x_2=4$ ] ] ] ]
   \end{tikzpicture}
   \end{center}

   \end{document}

Answer 1

我不知道如何使用tikz-qtree，但使用 TikZ，这很容易：

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{positioning}
\usetikzlibrary{trees}

\begin{document}

\begin{center}
\begin{tikzpicture}[sibling distance=150pt]
\tikzset{edge from parent/.style=
  {draw,
  edge from parent path={(\tikzparentnode.south)
  -- +(0,-17pt)
  -| (\tikzchildnode)}}}
\coordinate
child {node {$x_2=1$} edge from parent node[auto,swap,pos=0.08] {3}}
child {node {$x_2\neq1$}
  child {node {$x_2=2$} edge from parent node[auto,swap,pos=0.08] {4}}
  child {node {$x_2\neq2$}
    child {node {$x_2=3$} edge from parent node[auto,swap,pos=0.08] {5}}
    child {node {$x_2=4$}}
  }
};
\end{tikzpicture}
\end{center}

\end{document}