两条虚线完美交叉

Question

为了得到中间的十字，我们需要拨一个适当的dash pattern。我们希望实现有2n+1虚线和2n间隙。将间隙和虚线长度之间的比率称为r。然后虚线的长度a必须满足

2n r a + (2n+1) a = l ,

其中l是路径的长度。所以

a = l/(2n r + 2n +1)  .

在你的例子中，l是10cm（但我们可以让 Ti钾Z 测量带有装饰的（如果需要）。以下是和的\pgfdecoratedpathlength示例，您可以进行调整。n=15r=0.8

\documentclass[tikz]{standalone}% 'crop' is the default 
\begin{document}
\begin{tikzpicture}
\pgfmathsetmacro{\myr}{0.8}
\pgfmathsetmacro{\myn}{15}
\pgfmathsetmacro{\myl}{10cm}
\pgfmathsetmacro{\myon}{\myl/(2*\myn*\myr+2*\myn+1)}
\pgfmathsetmacro{\myoff}{\myr*\myon}
\typeout{\myon,\myoff}
\draw [line width=1.5pt,dash pattern=on \myon pt off \myoff pt] (0,5) -- (10,5);
\draw [line width=1.5pt,dash pattern=on \myon pt off \myoff pt] (5,0) -- (5,10);

\coordinate (c) at (5,5);   % center of circle
\def\radius{1}                % radius of circle
\def\nbpts{36}                   % nb of points
\def\radpt{1.0pt}                % radius of points
\colorlet{point color}{red}      % color of points
\foreach \numpt in {1,...,\nbpts}{\fill[point color] (c) ++ (360/\nbpts*\numpt:\radius) circle(\radpt);}
\end{tikzpicture}
\end{document}

您可以定义某种完整的破折号，其概念类似于杰克的完整正弦. 然后你可以说类似

\draw [line width=1.5pt,complete dashes={a=6mm}] (0,5) -- (10,5);

其中a是目标虚线长度。此外，您还可以指定上述比例r。但请注意，如果您在不同长度的路径上使用它，虚线长度只会在极少数情况下完全一致，但只要有许多虚线，它看起来就会大致相同。

\documentclass[tikz]{standalone}% 'crop' is the default
\usetikzlibrary{decorations.markings}
% earlier posts this post is conceptually similar to include
% https://tex.stackexchange.com/a/214448
% https://tex.stackexchange.com/a/25689
\makeatletter
\tikzset{%
    complete dashes/.style={/tikz/bob/settings={#1},
    decoration={
        markings,
        mark=at position 1 with {%
        \pgfmathtruncatemacro{\myn}{0.5+2*(\pgfdecoratedpathlength-\pgfkeysvalueof{/tikz/bob/a})/
        (2*\pgfkeysvalueof{/tikz/bob/a}*(1+\pgfkeysvalueof{/tikz/bob/r}))}%
        \pgfmathsetmacro{\myon}{\pgfdecoratedpathlength/(2*\myn*\pgfkeysvalueof{/tikz/bob/r}+2*\myn+1)}%
        \pgfmathsetmacro{\myoff}{\pgfkeysvalueof{/tikz/bob/r}*\myon}%
        \global\pgfutil@tempdima=\myon pt%
        \global\pgfutil@tempdimb=\myoff pt%
        %\typeout{\myon,\myoff}
        },
    },
    preaction=decorate,
    draw,dash pattern=on \pgfutil@tempdima off \pgfutil@tempdimb,
},bob/.cd,settings/.code={\tikzset{bob/.cd,#1}},
a/.initial=3mm,r/.initial=0.8
} 
\makeatother
\begin{document}
\begin{tikzpicture}
\draw [line width=1.5pt,complete dashes={a=6mm}] (0,5) -- (10,5);
\draw [line width=1.5pt,complete dashes={a=6mm}] (5,1) -- (5,9);

\coordinate (c) at (5,5);   % center of circle
\def\radius{1}                % radius of circle
\def\nbpts{36}                   % nb of points
\def\radpt{1.0pt}                % radius of points
\colorlet{point color}{red}      % color of points
\foreach \numpt in {1,...,\nbpts}{\fill[point color] (c) ++ (360/\nbpts*\numpt:\radius) circle(\radpt);}
\end{tikzpicture}
\end{document}

顺便说一句，我想我以前见过类似的东西，但我找不到完全匹配的。

Answer 1