如何畫出一個末端有箭頭的循環

Question

我試圖繪製一個從一點開始和結束的循環箭頭，但箭頭丟失了。這是代碼：

\begin{tikzpicture}

\node [circle,fill=black,inner sep=0,minimum size=4,label=below:\Large$P$] (P) at (0,0) {};
 
\draw (P) to [->,-stealth,thick,out=300,in=30,looseness=20] (P);

\end{tikzpicture}

顯示的是一個循環，但沒有箭頭。如何解決這個問題，使其顯示箭頭？

Answer 1

你想要這樣的東西嗎？

\documentclass[12pt]{article}
\usepackage{tikz}
\begin{document}
\begin{tikzpicture}
\node [circle, draw] (P) at (0,0) {$P$};
\draw[->,>= stealth]  (P) edge [out=120,in=60,distance=15mm]   (P);
\end{tikzpicture}
\end{document} 

更接近您的原始帖子，您還可以使用：

\begin{tikzpicture}
\node [circle, draw, fill=black, label=below:$P$] (P) at (0,0) {};
\draw[->,>= stealth]  (P) edge [out=120,in=60,distance=15mm]   (P);
\end{tikzpicture}

獲得

Answer 2

 \begin{tikzpicture}\tikzstyle{loop right} = [thick,->,>=stealth,  
    out=60,in=-60,looseness=20]
    
    
    \node [circle,fill=black,inner sep=0,minimum size=4pt,label= 
    {[yshift=-3pt]below:\Large$P$}] (P) at (0,0) {};
    
    \path (P) edge [loop right] (P);
    
 \end{tikzpicture}