我正在使用 dot2texi 进行一些测试，并从包文档中得到以下示例：
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows,shapes}
\usepackage{dot2texi}
\begin{document}
% Define layers
\pgfdeclarelayer{background}
\pgfdeclarelayer{foreground}
\pgfsetlayers{background,main,foreground}
% The scale option is useful for adjusting spacing between nodes.
% Note that this works best when straight lines are used to connect
% the nodes.
\begin{tikzpicture}[>=latex',scale=0.8]
% set node style
\tikzstyle{n} = [draw,shape=circle,minimum size=2em,
inner sep=0pt,fill=red!20]
\begin{dot2tex}[dot,tikz,codeonly,styleonly,options=-s -tmath]
digraph G {
node [style="n"];
A_1 -> B_1; A_1 -> B_2; A_1 -> B_3;
B_1 -> C_1; B_1 -> C_2;
B_2 -> C_2; B_2 -> C_3;
B_3 -> C_3; B_3 -> C_4;
}
\end{dot2tex}
% annotations
\node[left=1em] at (C_1.west) (l3) {Level 3};
\node at (l3 |- B_1) (l2){Level 2};
\node at (l3 |- A_1) (l1) {Level 1};
% Draw lines to separate the levels. First we need to calculate
% where the middle is.
\path (l3) -- coordinate (l32) (l2) -- coordinate (l21) (l1);
\draw[dashed] (C_1 |- l32) -- (l32 -| C_4);
\draw[dashed] (C_1 |- l21) -- (l21 -| C_4);
\draw[<->,red] (A_1) to[out=-120,in=90] (C_2);
% Highlight the A_1 -> B_1 -> C_2 path. Use layers to draw
8
% behind everything.
\begin{pgfonlayer}{background}
\draw[rounded corners=2em,line width=3em,blue!20,cap=round]
(A_1.center) -- (B_1.west) -- (C_2.center);
\end{pgfonlayer}
\end{tikzpicture}
\end{document}
当我尝试运行它时，pdflatex我收到消息（我的 tex 文件是qq4.tex）：
Opening dot2tex stream qq4-dot2tex-fig1.dot
Package dot2texi Warning: Conversion of qq4-dot2tex-fig1.dot failed..
Package dot2texi Warning: Please convert qq4-dot2tex-fig1.dot manually.
! Package pgf Error: No shape named C_1 is known.
See the pgf package documentation for explanation.
Type H <return> for immediate help.
...
l.27 \node[left=1em] at (C_1.west)
(l3) {Level 3};
?
我查看了手册，但什么也没找到。
有任何想法吗？