tikz 状态图中每 2 个组件都太接近了

Question

我已经编写（复制并粘贴）了下面的代码。

\documentclass[border=1cm]{standalone}
\usepackage{tikz}

\usetikzlibrary{automata, positioning, arrows}

\begin{document}

    \begin{tikzpicture}[]
    
        \node[state, initial, accepting] (1) {$1$};
        \node[state, below left of=1] (2) {$2$};
        \node[state, right of=2] (3) {$3$};
    
          \draw (1) edge[above] node{$b$} (2)
                (1) edge[below, bend right, left=0.3] node{$\epsilon$} (3)
                (2) edge[loop left] node{$a$} (2)
                (2) edge[below] node{$a, b$} (3)
                (3) edge[above, bend right, right=0.3] node{$a$} (1); 
    
    \end{tikzpicture}    

\end{document}

我得到了下面的图像。

但我希望代码能够生成下面的图像。

引用的代码和图片来自这里。

到底是怎么回事？

Answer 1

您应该使用包中定义的节点放置语法positioning或省略此包并增加节点距离例如 33 毫米。

在前一种情况下，用于标记边的 MWE 使用quotes库是：

\documentclass[border=1cm]{standalone}
\usepackage{tikz}

\usetikzlibrary{arrows.meta, automata, 
                positioning,
                quotes}

\begin{document}

    \begin{tikzpicture}[
node distance = 15mm and 15 mm,
every edge/.append style = {draw, -{Straight Barb[scale=0.8]}},
every edge quotes/.style = {auto=right, font=\small, inner sep=2pt}
                        ]
% nodes
\node[state, initial, accepting] (1) {$1$};
\node[state, below left= of 1] (2) {$2$};
\node[state, right= of 2] (3) {$3$};
% arrows
\path   (1) edge["$b$"] (2)
            edge[bend right, "$\epsilon$"] (3)
        (2) edge[loop left,"$a$" '] ()
            edge["{$a, b$}"] (3)
        (3) edge[bend right, "$a$"] (1);
    \end{tikzpicture}

\end{document}