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How to draw with TikZ multiple curved lines which are merged into one line? Below is an example how it should look like:

enter image description here

I tried the following code, but that looks ugly as hell:

\draw[] (2.4,5.4) .. controls (2.4,4.2) and (2.8,4.2) .. (7,8.5); 
\draw[] (2,7.6) .. controls (1.8,8.6) and(3,8.5) .. (7,8.5); 
\draw[] (1.55,7.6) .. controls (1.7,8.6) and(3,8.5) .. (7,8.5); 
\draw[] (9.8,4) .. controls (8.5,5) and (8,6) .. (7,8.5); 
\draw[] (7,8.5) .. controls (7,12) and (6,13.5) .. (5,13.5);

enter image description here

19yc93
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  • Welcome! Can you provide what you already tried? Maybe an MWE we can improve on? – Sango Jan 27 '20 at 14:41
  • Draw them as bezier curves ( I normally use a series of (pkt1) .. controls ++(ang1:rad1) and ++(ang2:rad2) .. (pkt) ..., then make sure that the direction of the control point (the two polar coordinates I used) at the "convergens" is the same – daleif Jan 27 '20 at 15:01

1 Answers1

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Welcome to TeX.SE. This kind of drawing can be done with the to path operation, its in and out options to specify incoming and outgoing angles at interesting points, the attach arrow style from Schrödinger's cat and... a bit of patience.

\documentclass[tikz,border=2mm]{standalone}
\usetikzlibrary{decorations.markings, arrows.meta, bending}

% 'attach arrow' style from Schrödinger's cat:
% <https://tex.stackexchange.com/a/524935/73317>
\tikzset{%
    attach arrow/.style={
    decoration={
        markings,
         mark=at position 0 with {\pgfextra{%
         \pgfmathsetmacro{\tmpArrowTime}{\pgfkeysvalueof{/tikz/arc arrow/length}/(\pgfdecoratedpathlength)}%
         \xdef\tmpArrowTime{\tmpArrowTime}}},
        mark=at position {#1-3*\tmpArrowTime} with {\coordinate(@1);},
        mark=at position {#1-2*\tmpArrowTime} with {\coordinate(@2);},
        mark=at position {#1-1*\tmpArrowTime} with {\coordinate(@3);},
        mark=at position {#1+\tmpArrowTime/2} with {\coordinate(@4);
        \draw[-{Stealth[length=\pgfkeysvalueof{/tikz/arc arrow/length},bend]}]
          plot[smooth] coordinates {(@1) (@2) (@3) (@4)};},
        },
     postaction=decorate,
     },
     attach arrow/.default=0.5,
     arc arrow/length/.initial=2mm,
}

\begin{document}
\begin{tikzpicture}
  \draw[attach arrow=0.2, attach arrow=0.83]
    (-6,-2) to[out=45, in=180] (-4,-1) to[out=0, in=180] (-1.7,-1.8)
    to[out=0, in=-95] (0,0) to[out=85, in=0] (-3,2) to[out=180, in=70] (-5,1);
  \draw[attach arrow=0.5] (-6.5,-4) to[out=-30, in=180] (-5.5,-4.2)
    to[out=0, in=180] (-3,-3) to[out=0, in=205] (-1.1,-3)
    to[out=25, in=-95] (0,0);
  \draw[attach arrow=0.3] (-1.5,-8) to[out=110, in=260] (-0.2,-2.5)
    to[out=80, in=-95] (0,0);
\end{tikzpicture}
\end{document}

screenshot

frougon
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