椭圆之间的弯曲箭头

Question

我想将下图中的双箭头改为两个弯曲箭头，每个箭头都以椭圆开始和结束。我在下图中用颜料更精确地说明了我的意思：

\begin{tikzpicture}
\def\firstellipse{(0,0) ellipse (2 and 1)}
\def\secondellipse{(5,0) ellipse (2 and 1)}
\def\thirdellipse{(2.5,2.5) ellipse (2 and 1)}
\filldraw[fill=red!20]\firstellipse;
\filldraw[fill=blue!20]\secondellipse;
\filldraw[fill=green!20]\thirdellipse;
\node (A) at (2.5,2.5) {Variation};
\node (B) at (5,0) {Modifikation};
\node (C) at (0,0) {Reflexion};
\draw [thick,densely dotted, latex -latex] (A)->(B);
\draw [thick,densely dotted, latex -latex] (A)->(C);
\draw [thick,densely dotted, latex -latex] (C)->(B);
\end{tikzpicture}

Answer 1

如果您使用节点来绘制椭圆，那就变得非常容易，因为您使用例如a.120作为坐标，其中a是节点名称，120是角度。

这是一种可能的实现，其中使用 添加文本label。

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes.geometric}
\begin{document}
\begin{tikzpicture}[
  ell/.style 2 args={
    ellipse,
    minimum width=4cm,
    minimum height=2cm,
    draw,
    label={[name=#1]center:#2}
  },
  connection/.style={thick,densely dotted, latex-latex}
]
\node [ell={A}{Variation},   fill=green!20] (a) at (2.5,2.5) {};
\node [ell={B}{Modifikation},fill=red!20]   (b) at (5,0) {};
\node [ell={C}{Reflexion},   fill=blue!20]  (c) at (0,0) {};

\draw [connection] (A)->(B);
\draw [connection] (A)->(C);
\draw [connection] (C)->(B);

\draw [-latex] (b.120) to[bend right] (a.330);
\draw [-latex] (a.300) to[bend right] (b.150);
\end{tikzpicture}

\end{document}

Answer 2

出色地，Torbjørn T.午餐时间咬我一下 :-( 无论如何，我的（非常相似的）解决方案：

\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{arrows.meta, positioning, shapes}
\begin{document}
    \begin{tikzpicture}[
node distance = 7mm and 7mm,
 E/.style = {ellipse, draw, 
             fill=#1,
             minimum width=22mm, inner xsep=0mm, inner ysep=3mm},
DL/.style = {thick, densely dotted, Latex-Latex,
             shorten >=#1, shorten <=#1},
DL/.default = 4mm,
BL/.style = {thick, -Latex, bend left}
            ]
\node (A)  [E=green!20]                         {Variation};
\node (B)  [E=green!20, below left =of A.south] {Modifikation};
\node (C)  [E=green!20, below right=of A.south] {Reflexion};
\draw [DL]  (A.center) -- (B.center);
\draw [DL]  (A.center) -- (C.center);
\draw [DL=-4mm]  (B.east) -- (C.west);
%
\draw[BL]   (A) to (C);
\draw[BL]   (C) to (A);
\end{tikzpicture}
\documentclass[tikz, margin=3mm]{standalone}
\usetikzlibrary{arrows.meta, positioning, shapes}
\begin{document}