曲线上等距的点**及其相关坐标**

Question

我希望沿着曲线绘制间隔开的点，并为每个点分配一个唯一的坐标，以便该坐标可用作箭头的端点等。从这个帖子，以下代码绘制了一条等间距点的曲线没有指定坐标：

\usetikzlibrary{hobby}
\usetikzlibrary{decorations.markings}
\tikzset{equally spaced dots/.style={postaction={decorate,
      decoration={markings,% switch on markings 
        mark=% actually add a mark
        between positions 0 and 1 step 0.9999/#1
        with
        {
          \fill circle (1pt);
        }
      }}}}

\begin{document}

\begin{tikzpicture}
  \draw[equally spaced dots=5] (0,0) (0,0) to[curve through={(6,4) .. (4,9) .. (1,7)}]
  (3 ,5);
\end{tikzpicture}

\end{document}

我的问题是 - 我该如何为每个点分配一个坐标？例如，第 i 个点应该有坐标c-i（这样最后我就有了坐标c-1, c-2, ...，c-6可以用来处理上面的例子）。

Answer 1

\pgfkeysvalueof{/pgf/decoration/mark info/sequence number}我想，您正在寻找。

\documentclass[tikz,border=3.14mm]{standalone}
\usetikzlibrary{hobby}
\usetikzlibrary{decorations.markings}
\tikzset{equally spaced dots/.style={postaction={decorate,
      decoration={markings,% switch on markings 
        mark=% actually add a mark
        between positions 0 and 1 step 0.9999/#1
        with
        {
          \node[circle,fill,inner sep=1pt](c-\pgfkeysvalueof{/pgf/decoration/mark info/sequence number}){};
        }
      }}}}

\begin{document}

\begin{tikzpicture}
  \draw[equally spaced dots=5] (0,0) (0,0) to[curve through={(6,4) .. (4,9) .. (1,7)}]
  (3 ,5);
  \draw[red] (c-2) -- (c-4);
\end{tikzpicture}

\end{document}

红线是为了表明它有效。