使用 tikz 包在 Latex 中绘制树的问题

Question

我试图构造一棵树，但 Latex 没有绘制它，也没有显示任何具体错误或警告。代码有什么问题？

\documentclass[a4paper,12pt]{article}

\usepackage{cmap}                   
\usepackage{mathtext}               
\usepackage[T2A]{fontenc}           
\usepackage[utf8]{inputenc}
\usepackage[english,russian]{babel} 
\usepackage{amsmath,amsfonts,amssymb,amsthm,mathtools} 
\usepackage{icomma} 

\newcommand*{\hm}[1]{#1\nobreak\discretionary{}
{\hbox{$\mathsurround=0pt #1$}}{}}

\usepackage{graphicx}  
\setlength\fboxsep{3pt} 
\setlength\fboxrule{1pt}
\usepackage{wrapfig}

\usepackage{array,tabularx,tabulary,booktabs} 
\usepackage{longtable}  
\usepackage{multirow} 

\theoremstyle{remark} 
\newtheorem*{nonum}{Solution}

\usepackage{etoolbox} 

\usepackage{lastpage} 

\usepackage{soulutf8} 

\usepackage{hyperref}
\usepackage[usenames,dvipsnames,svgnames,table,rgb]{xcolor}

\usepackage{multicol} 
\usepackage{tikz}
\usetikzlibrary{trees}
\usetikzlibrary{matrix}

\begin{document}

\section{drawing a tree}

\begin{tikzpicture}[>=stealth,sloped]
  \matrix (tree) [matrix of nodes, column sep=2cm]
          {
            &     &     &     &     &    & $\a$ \\
            &     &     &     & \   &    &\\
            &     &     &     &     &    & $\b$ \\
            &     & \   &     &     &    &\\
            &     &     &     &     &    & $\c$ \\
         \  &     &     &     & \   &    &\\
            &     &     &     &     &    & $\d$ \\
            &     &     &     &     &    & \\
            &     & \   &     &     &    & $\e$ \\
            &     & \   &     & \   &    &\\
            &     &     &     &     &    & $\f$ \\

          };
          \draw[->] (tree-6-1)--(tree-4-3) node [midway,above] {$\alpha$};
          \draw[->] (tree-6-1)--(tree-10-5) node [midway,below] {$(1-\alpha)$};
          \draw[->] (tree-4-3)--(tree-2-5) node [midway,above] {$\delta$};
          \draw[->] (tree-4-3)--(tree-6-5) node [midway,below] {$(1-\delta)$};
          \draw[->] (tree-2-5)--(tree-1-7);
          \draw[->] (tree-2-5)--(tree-3-7);
          \draw[->] (tree-6-5)--(tree-5-7);
          \draw[->] (tree-6-5)--(tree-7-7);
          \draw[->] (tree-10-5)--(tree-9-7);
          \draw[->] (tree-10-5)--(tree-11-7);     

\end{tikzpicture}



\end{document}

Answer 1

Gregory，您在用值定义矩阵后跳过了该行。显然，“};”之前的行被遗漏了，导致语法错误。

Answer 2

作为对 @user1146332 的回答 (+1) 的补充。添加了边缘标签的自动定位和一些小改进：

\documentclass[margin=3mm]{standalone}
\usepackage{forest}
\usetikzlibrary{arrows.meta}
\tikzset{
ELS/.style = {% Edge Label Style
              pos=0.5, sloped, node font=\footnotesize, text=blue,
              inner sep=2pt, anchor=#1},
        }

\begin{document}
    \begin{forest}
for tree={
% nodes
inner sep=2pt,
math content,
% tree
    grow'=east,
   anchor=west,
    l sep=12mm,
    s sep=2mm,
     edge={semithick,-Stealth}%
        },
EL/.style={if n=1{edge label={node[ELS=south]{$#1$}}}
                 {edge label={node[ELS=north]{$#1$}}}}
[
   [, EL=\alpha
        [, tier=L2, EL=\delta,
            [\epsilon]
            [\epsilon+\mu]
        ]
        [, tier=L2, EL=(1-\delta)
            [\epsilon+\mu]
            [\epsilon]
        ]
    ]
    [, tier=L2, EL=(1-\delta)
        [\epsilon]
        [\epsilon]
    ]
]
    \end{forest}
\end{document}

Answer 3

我看到你已经修复了代码。但是，如果你想用类似的 tikz 代码映射几棵树，你可能会精神崩溃。软件开发人员会说你的代码的可维护性很差。而且因为编码也应该很有趣，所以你应该考虑尝试其他方法。

我想向您展示利用该forest包的树的另一种实现方式。

您forest可以采用更加通用的方法，同时又具有高度的可定制性。

\documentclass[a4paper,10pt]{article}

\usepackage{forest}

\forestset{
    e-label/.style 2 args = {
        edge label={
            node[midway, #2, sloped]{#1}
        }
    }
}

\begin{document}

\begin{forest}
    for tree={
        grow'=east, 
        l sep=1.5cm,
        edge={->, >=stealth},
        anchor=west,
        child anchor=west
    },
    [
        [, e-label={$\alpha$}{above}
            [, e-label={$\delta$}{above}, tier=second
                [$\epsilon$]
                [$\epsilon +\mu$]
            ]
            [, e-label={$(1-\delta)$}{below}
                [$\epsilon +\mu$]
                [$\epsilon$]
            ]
        ]
        [, e-label={$(1-\alpha)$}{below}, tier=second
            [$\epsilon$]
            [$\epsilon$]
        ]
    ] 
\end{forest}

\end{document}