\pgfmath@dimen@@ 的参数有一个额外的 }

Question

使用TikZ和pgf版本v3.1.9a (3.1.9a)，我尝试编译以下代码

\documentclass[tikz,border=5]{standalone}
\usetikzlibrary{trees,mindmap}
\tikzset{grow cyclic list/.code={%
  \def\tikzgrowthpositions{{#1}}%
  \foreach \n [count=\i,remember=\i]in {#1}{}%
  \let\tikzgrowthpositionscount=\i%
  \tikzset{growth function=\tikzgrowcycliclist}}}
\def\tikzgrowcycliclist{%
  \pgftransformshift{%
    \pgfpointpolar{\tikzgrowthpositions[mod(\the\tikznumberofcurrentchild-1,\tikzgrowthpositionscount)]}%
      {\the\tikzleveldistance}}}
\begin{document}
\begin{tikzpicture}[small mindmap, concept color=blue!20,  
  every child node/.style={concept}]
\node [concept] (languages) 
  {O} [grow cyclic list={90,0,-45,210}] 
    child { node {A} }
    child { node {B} }
    child { node {C} 
      [clockwise from=0, sibling angle=45]
      child { node {C1} }
      child { node {C1} }
      child { node {C1} }
    }
    child { node {D} };
\end{tikzpicture}
\end{document}

这是 Mark Wibrow 的回答的一部分这里。但它抛出了以下错误：

\pgfmath@dimen@@ 的参数有一个额外的}。^^Ichild { node {D} };

有人知道如何解决吗？

Answer 1

问题在于，旧答案利用了\foreach现已修复的错误功能。

实际情况是，被“记住”的“计数”在 的末尾仍然可用\foreach，但这是错误的：你会破坏 的含义\i。如果你在某个节点中有一个重音符号“î”……

有一种更简单的方法来计算列表的元素数量：

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{trees,mindmap}

\ExplSyntaxOn
\cs_set_eq:NN \clistcount \clist_count:n
\ExplSyntaxOff

\tikzset{
  grow cyclic list/.code={%
    \def\tikzgrowthpositions{{#1}}%
%    \foreach \n [count=\i,remember=\i]in {#1}{\global\let\tikzgrowthpositionscount=\i}%
    \edef\tikzgrowthpositionscount{\clistcount{#1}}%
    \tikzset{growth function=\tikzgrowcycliclist}
  }
}

\def\tikzgrowcycliclist{%
  \pgftransformshift{%
    \pgfpointpolar{%
      \tikzgrowthpositions[mod(\the\tikznumberofcurrentchild-1,\tikzgrowthpositionscount)]%
    }%
    {\the\tikzleveldistance}
  }%
}

\begin{document}

\begin{tikzpicture}[
  small mindmap,
  concept color=blue!20,  
  every child node/.style={concept}
]
\node [concept] (languages) 
  {O} [grow cyclic list={90,0,-45,210}] 
    child { node {A} }
    child { node {B} }
    child { node {C} 
      [clockwise from=0, sibling angle=45]
      child { node {C1} }
      child { node {C1} }
      child { node {C1} }
    }
    child { node {D} };
\end{tikzpicture}

\end{document}

我留下了替代\foreach方法的评论，但我的建议更有效。

对于“纯钛钾“Z”解决方案

\tikzset{
  grow cyclic list/.code={%
    \def\tikzgrowthpositions{{#1}}%
    \pgfmathsetmacro\tikzgrowthpositionscount{dim({#1})}%
    \tikzset{growth function=\tikzgrowcycliclist}
  }
}

Answer 2

我认为\tikzgrowthpositionscount需要在循环内设置\foreach，并且应将其设为全局变量，以便在循环外可访问。该remember选项仅存储最后一个项目的值，但不会使变量在 for 循环外可访问（可能在某个时间点已更改）。

\documentclass[tikz,border=5]{standalone}
\usetikzlibrary{trees,mindmap,calc}
\tikzset{grow cyclic list/.code={%
  \def\tikzgrowthpositions{{#1}}%
  \foreach \n [count=\i]in {#1}{%
    \global\let\tikzgrowthpositionscount=\i%
  }%
  \tikzset{growth function=\tikzgrowcycliclist}}}
\def\tikzgrowcycliclist{%
  \pgftransformshift{%
    \pgfpointpolar{\tikzgrowthpositions[mod(\the\tikznumberofcurrentchild-1,\tikzgrowthpositionscount)]}%
      {\the\tikzleveldistance}}}
\begin{document}
\begin{tikzpicture}[small mindmap, concept color=blue!20,  
  every child node/.style={concept}]
\node [concept] (languages) 
  {O} [grow cyclic list={90,0,-45,210}] 
    child { node {A} }
    child { node {B} }
    child { node {C} 
      [clockwise from=0, sibling angle=45]
      child { node {C1} }
      child { node {C1} }
      child { node {C1} }
    }
    child { node {D} };
\end{tikzpicture}
\end{document}