How to draw an eight contour

Question

I need to draw a contour used in some exercises related to complex integration called eight contour, just like in the following image. The main problem for me is to get the shape around the auto-intersection. Have a nice week!

See this question about drawing curves. – Karlo Jul 25 '22 at 14:09 — Karlo, Jul 25 '22 at 14:09

score 2 · Accepted Answer · answered Jul 26 '22 at 00:20

An example how you can do it in TIKZ only:

\documentclass[border=1cm]{standalone}
\usepackage{tikz}
\usetikzlibrary{decorations.markings}
\begin{document}
\begin{tikzpicture}

    \draw[decoration={markings, mark=at position 0.25 with {\arrow{&gt;}}},postaction={decorate},decoration={markings, mark=at position 0.75 with {\arrow{&gt;}}},postaction={decorate}]  
    (-1,0) to[out=90, in=125, looseness=2] (1,0) to[out=-55, in=-90, looseness=2] (2.5,0);

    \draw[decoration={markings, mark=at position 0.25 with {\arrow{&lt;}}},postaction={decorate},decoration={markings, mark=at position 0.75 with {\arrow{&lt;}}},postaction={decorate}] 
    (-1,0) to[out=-90, in=-125, looseness=2] (1,0) to[out=55, in=90, looseness=2] (2.5,0);

    \draw[stealth-stealth] (0,-2) -- (0,4);
    \draw[stealth-stealth] (-2,0) -- (4,0);
    \filldraw [color=blue!50] (0,0) circle (2pt);
    \filldraw [color=blue!50] (2,0) circle (2pt);


\end{tikzpicture}



\end{document}

How to draw an eight contour

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