Tikz 绘制自动机..

Question

我已经能够绘制状态以及状态之间的箭头。我对自动机周围的“标签”有问题（I、E、P 和 R）。有什么想法吗？

Answer 1

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{matrix,positioning,calc}
\begin{document}
\begin{tikzpicture}
\matrix[matrix of nodes,nodes in empty cells,column sep=3.14mm,row sep=3.14mm,
nodes={draw,circle,fill=cyan!50,minimum size=1cm}] (mat) {
 & & & \\
 & & & \\
};
\node[left=3.14mm of mat-1-1,font=\sffamily] {P};
\node[left=3.14mm of mat-2-1,font=\sffamily] {R};
\path ($(mat-1-1.north)!0.5!(mat-1-2.north)$) coordinate (x1)
($(mat-1-2.north)!0.5!(mat-1-3.north)$) coordinate (x2)
($(mat-1-3.north)!0.5!(mat-1-4.north)$) coordinate (x3)
($(mat-2-2.south)!0.5!(mat-2-3.south)$) coordinate (x4);
\node[above=3.14mm of x1,font=\sffamily] {I};
\node[above=3.14mm of x3,font=\sffamily] {E};
\draw[dotted] (x2) -- (x4);
\end{tikzpicture}
\end{document}