我想在 tikzcd 中绘制无限循环（用虚线循环表示它一直持续到无穷大）？

Question

我正在使用 tikzcd。我有一个顶点和 n 个循环。我希望前几个循环是实线，后面的循环是虚线，以表示还有更多循环。我是 Latex 的新手，不太了解，所以尝试以简单的方式呈现它。

\documentclass[11pt]{article}
\usepackage{tikz-cd}
\usepackage{tikz}
\usepackage{tikz}
\begin{document}
\begin{equation}
\tikzset{vertex/.style = {shape=circle,draw,minimum size=1.5em}}
\tikzset{edge/.style = {->,> = latex'}}
\begin{tikzpicture}
   \node (a) at (0,2) {a};
   \path[->] (a) edge [loop left, "$e_{n-1}$"]  (a);
   \path[->] (a) edge [loop right, "$e_1$"]  (a);
   \path[->] (a) edge [loop above, "$e_n$"]  (a);
   \path[->] (a) edge [loop below, "$e_2$"]  (a);
\end{tikzpicture}
\end{equation}
\end{document}

这只是 o4 个循环，我想要超过 4 个。我想要 n 个这样的循环，其中一些带点。

Answer 1

你可能期望这样的事情：

\documentclass[11pt]{article}
\usepackage{tikz}
\usetikzlibrary{arrows,
                quotes}
\tikzset{
every edge quotes/.append style = {font=\footnotesize},
       every edge/.append style = {> = stealth, % arrowhead can be changed only on the such way
                                   draw=red, semithick},
                  vertex/.style = {shape=circle, draw, minimum size=1.5em, inner sep=2pt}
        }

\begin{document}
\begin{equation}
    \begin{tikzpicture}[baseline=(current bounding box.center)]
\node   (a) [vertex] {a};
\path[scale=2] % <--- scaled loops size
        (a) edge [loop right, "$e_1$"]
        (a) edge [out=-30, in=-60, distance=5mm, ->, "$e_2$"] (a)
        (a) edge [loop above, "$e_{n-1}$"]
        (a) edge [out= 60, in= 30, distance=5mm, ->, "$e_n$"] (a);
\draw [densely dotted]  (285:1.5em) arc (285:120:1.5em);
    \end{tikzpicture}
\end{equation}
\end{document}