TikZ 中的右侧轮廓积分图

Question

如何在 Ti 中绘制附图钾Z 环境？

Answer 1

像这样（网格仅供参考点）？

代码：

\documentclass[10pt,a4paper]{article}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\begin{document}
    \begin{tikzpicture}[scale=2,decoration={markings, 
            mark= between positions 0.2 and 0.8 step 30mm 
            with {\arrow{latex}}}
        ] 
        \draw[gray!20] (-5,-3) grid[step=.5] (3,3);
        \draw[postaction={decorate},line width=3pt] (-4.5,1)--(-1.73,1);
        \draw[postaction={decorate},line width=3pt] (-1.73,1) arc (150:-150:2);
        \draw[postaction={decorate},line width=3pt] (-1.73,-1)--(-4.5,-1);
        \draw[-latex] (-5,0)--(2.5,0) node[right] () {$x$};
        \draw[-latex] (0,-2.5)--(0,2.5) node[above] () {$y$};
    \end{tikzpicture}
\end{document}

Answer 2

如果您希望路径平滑，我强烈建议您避免将其分为三个不同的部分。见下图：

以下是用一行代码完成此操作的方法：

\documentclass[tikz,border=3.14mm]{standalone}

\begin{document}
    
    \begin{tikzpicture}
        \draw[line width=2pt] ([xshift=-2cm]2:150) -- (2:150) arc[start angle=150, end angle=-150, radius=2] --++ (-2,0);
    \end{tikzpicture}
    
\end{document}