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如何在弯曲边缘的中心创建节点

tag-icon • tag-icon tikz-pgf graphs
如何在弯曲边缘的中心创建节点

我希望绘制一个图形，使得红色顶点恰好位于每个蓝色边的中心。代码如下：

\begin{tikzpicture}
\tikzset{pointblue/.style={fill=blue, circle, minimum width=3pt, scale=0.6}}
\tikzset{pointred/.style={fill=red, circle, minimum width=3pt, scale=0.6}}

% blues vertices
\coordinate (X) at (-0.5,0);
\coordinate (Z) at (2,-1.5);
\coordinate (T) at (-0.5,2);
%% blues vertices.
\node at (X) [pointblue] (x) {};
\node at (Z) [pointblue] (z) {};
\node at (T) [pointblue] (t) {};

%%% blues edges
\draw[thick, blue] (z) edge[bend right=25] (x);
\draw[thick, blue] (z) edge[bend left=45] (x);

\draw[thick, blue] (x) -- (t);
\draw[thick, blue] (x) edge[bend left=60] (t);
\draw[thick, blue] (x) edge[bend right=60] (t);

% reds vertices
\coordinate (X2T2) at (-1,1);
\coordinate (X1T1) at ($(X)!.5!(T)$);
\coordinate (XT) at (0,1);

\coordinate (ZX) at (1,-0.5);
\coordinate (Z1X1) at (0.5,-1.3);

% reds vertices.
\node at (ZX) [pointred] (zx) {};
\node at (Z1X1) [pointred] (z1x1) {};

\node at (XT) [pointred] (xt) {};
\node at (X1T1) [pointred] (x1t1) {};
\node at (X2T2) [pointred] (x2t2) {};

% reds edges
\draw[thick, red] (x2t2) edge[bend right = 60] (z1x1);

\end{tikzpicture}

目前的情况如下：

数字

我正在手动计算红色顶点的坐标（请注意，它们不在中心）。我知道如何计算没有弯曲的边缘的中心坐标（例如，在我使用的代码中：）\coordinate (X1T1) at ($(X)!.5!(T)$);。有没有办法计算有弯曲的蓝色边缘的中心，而无需手动完成？

答案1

您不需要单独定义节点的坐标。只需使用

\node[pointblue] at (-0.5,0) (x){};

红色节点可以用作语句midway的一部分进行定义\draw。此外，\draw当语句具有相同的样式时，可以将它们组合在一起，并且可以在一个语句中定义多种样式tikzset。

在此处输入图片描述

\documentclass{article}

\usepackage{tikz}

\tikzset{pointblue/.style={fill=blue, circle, minimum width=3pt, scale=0.6},
    pointred/.style={fill=red, circle, minimum width=3pt, scale=0.6}}
    
\begin{document}

\begin{tikzpicture}

% blues vertices
\node[pointblue] at (-0.5,0) (x){};
\node[pointblue] at (2,-1.5) (z){};
\node[pointblue] at (-0.5,2) (t){};

%%% blues edges
\draw[thick, blue] (z) to[bend right=25] node[pointred, midway] (zx){} (x)
    (z) to[bend left=45]node[pointred, midway] (z1x1){} (x)
    (x) to node[pointred, midway](x1t1){} (t)
    (x) to[bend left=60] node[pointred, midway] (x2t2){} (t)
    (x) to[bend right=60] node[pointred, midway] (xt){} (t);

% reds edges
\draw[thick, red] (x2t2) to[bend right = 60] (z1x1);

\end{tikzpicture}

\end{document}

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