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制作圆形箭头弧的简单方法？

tag-icon • tag-icon tikz-pgf asymptote
制作圆形箭头弧的简单方法？

我有 4 个不同大小的圆形节点。

有没有简单的方法（TikZ，Asymptote，...）将它们与圆形箭头弧连接起来？

在此处输入图片描述

\documentclass[border=5mm,tikz]{standalone}
\begin{document}
\begin{tikzpicture}[every node/.style={circle,draw,fill=white}]
\def\r{3}
\draw[red] (0,0) circle (\r);

% 4 nodes with different sizes
\path
(180:\r) node (Sp) {Spring}
(90:\r)  node (Su) {Summer}
(0:\r)   node (Au) {Autumn}
(-90:\r) node (Wi) {Winter};

% How to make arrow arcs cicular? (the red one with arrow tips)
\begin{scope}[-stealth,bend left]
\draw (Sp) to (Su);
\draw (Su) to (Au);
\draw (Au) to (Wi);
\draw (Wi) to (Sp);
\end{scope}
\end{tikzpicture}
\end{document}

答案1

Asymptote这是使用真弧来实现的一种方法。

函数返回两个路径相交处intersect的数组。该函数将圆弧修剪到相交处。timesubpathtime

我没有将代码包装到 LaTeX 文档中，因为我倾向于使用命令来处理 Asymptote asy。

unitsize(1inch);

path Autumn = shift( 1, 0)*scale(0.35)*unitcircle;
path Winter = shift( 0,-1)*scale(0.30)*unitcircle;
path Spring = shift(-1, 0)*scale(0.32)*unitcircle;
path Summer = shift( 0, 1)*scale(0.36)*unitcircle;

draw(Autumn);
draw(Winter);
draw(Spring);
draw(Summer);

label("Autumn", ( 1, 0));
label("Winter", ( 0,-1));
label("Spring", (-1, 0));
label("Summer", ( 0, 1));

path p1 = arc((0,0), 1, 0, -90);
draw(subpath(p1, intersect(p1,Autumn)[0], intersect(p1,Winter)[0]), red, Arrow);

path p2 = arc((0,0), 1, 270, 180);
draw(subpath(p2, intersect(p2,Winter)[0], intersect(p2,Spring)[0]), red, Arrow);

path p3 = arc((0,0), 1, 180, 90);
draw(subpath(p3, intersect(p3,Spring)[0], intersect(p3,Summer)[0]), red, Arrow);

path p4 = arc((0,0), 1, 90, 0);
draw(subpath(p4, intersect(p4,Summer)[0], intersect(p4,Autumn)[0]), red, Arrow);

在此处输入图片描述

答案2

您可以计算节点边界和圆的交点来绘制圆弧。为了方便起见，我将所有内容都打包在一张图片中。我保留了红色圆圈以证明圆弧完美覆盖了它。

\documentclass[border=5mm,tikz]{standalone}
\usetikzlibrary{arrows.meta,bending,calc,intersections}
\begin{document}
\begin{tikzpicture}[every node/.style={circle,draw,fill=white},
 pics/circular arc/.style args={from #1 to #2}{code={
 \path[name path=arc] 
  let \p1=(#1),\p2=(#2),\n1={atan2(\y1,\x1)},\n2={atan2(\y2,\x2)},
    \n3={ifthenelse(abs(\n1-\n2)<180,\n2,\n2-360)}
  in (\n1:\r) arc(\n1:\n3:\r);
 \draw[-{Stealth[bend]},pic actions,
    name intersections={of=#1 and arc,by=arcstart},
    name intersections={of=#2 and arc,by=arcend}] 
    let \p1=(arcstart),\p2=(arcend),\n1={atan2(\y1,\x1)},\n2={atan2(\y2,\x2)},
     \n3={ifthenelse(abs(\n1-\n2)<180,\n2,\n2-360)}
  in (\n1:\r) arc(\n1:\n3:\r);
 }}]
\def\r{3}
\draw[red] (0,0) circle (\r);

% 4 nodes with different sizes
\path
(180:\r) node[name path=Sp] (Sp) {Spring}
(90:\r)  node[name path=Su] (Su) {Summer}
(0:\r)   node[name path=Au] (Au) {Autumn}
(-90:\r) node[name path=Wi] (Wi) {Winter};

% How to make arrow arcs cicular? (the red one with arrow tips)
\begin{scope}[-stealth,bend left]
 \path pic{circular arc=from Sp to Su}
    pic{circular arc=from Su to Au}
    pic{circular arc=from Au to Wi}
    pic{circular arc=from Wi to Sp};

\end{scope}
\end{tikzpicture}
\end{document}

在此处输入图片描述

答案3

这就是graphdrawing 图书馆necklace routing是为……而生的。

代码

% !TeX TS-program = lualatex
\documentclass[tikz]{standalone}
\usetikzlibrary{
  arrows.meta, bending,  % for Stealth arrow tips and bended arrow tips
  graphs, graphdrawing}  % for \graph syntax and \usegdlibrary → needs LuaTeX
\usegdlibrary{
  circular,        % for simple necklace layout
  routing}         % for necklace routing
\tikzgraphsset{
  circ routing/.style={
    /tikz/>={Stealth[sep,bend]},
    nodes={draw, circle},
    radius=3cm,
    ->, cycle,              % all edges are directed, last connects to first
    simple necklace layout, % place nodes on a circle
    grow'=down,             % first node is at the top, ' = clockwise
    necklace routing}}      % make connections follow the circle
\begin{document}
\tikz\graph[circ routing]{Summer, Autumn, Winter, Spring};
\end{document}

输出（添加了半径为3cm的圆）

在此处输入图片描述

答案4

我刚刚用库找到了一个看似简单的方法angles。每个圆形箭头弧都是一个角度标记。

在此处输入图片描述

\documentclass[border=5mm,tikz]{standalone}
\usetikzlibrary{angles}
\begin{document}
\begin{tikzpicture}[every node/.style={circle,draw,fill=white}]
\def\r{3}
\draw[red] (0,0) circle (\r);

% 4 nodes with different sizes
\path
(0,0) coordinate (O)
(180:\r) node (Sp) {Spring}
(90:\r)  node (Su) {Summer}
(0:\r)   node (Au) {Autumn}
(-90:\r) node (Wi) {Winter};

% Make arrow arcs cicular using angles library as angle mark
\path
(Sp.north) coordinate (SpN)
(Su.west) coordinate (SuW)
pic[draw=blue,fill=none,stealth-,angle radius=\r cm]{angle=SuW--O--SpN}
(Su.east) coordinate (SuE)
(Au.north) coordinate (AuN)
pic[draw=blue,fill=none,stealth-,angle radius=\r cm]{angle=AuN--O--SuE};
\end{tikzpicture}
\end{document}

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