沙路法最小工作示例

\documentclass{minimal}

\usepackage{pgf}
\usepackage{tikz}

\usetikzlibrary{matrix}
% \usetikzlibrary{arrows}
% \usetikzlibrary{shapes}
% \usetikzlibrary{patterns}
% \usetikzlibrary{decorations.pathmorphing}
% \usetikzlibrary{positioning}
% \usetikzlibrary{fit}
% \usetikzlibrary{snakes}


\newcommand{\red}{\textcolor{red}}


\begin{document}

  \begin{figure}[htbp]
    \centering
    \begin{tikzpicture}
      \matrix(A) [matrix of math nodes,nodes in empty cells,ampersand replacement=\&,row sep=15pt,column sep=15pt] {
        \&  a_{11} \& a_{12} \& a_{13}  \& \red{a_{11}} \& \red{a_{12}} \&\\
        \&  a_{21} \& a_{22} \& a_{23}  \& \red{a_{21}} \& \red{a_{22}} \&\\
        \&  a_{31} \& a_{32} \& a_{33}  \& \red{a_{31}} \& \red{a_{32}} \&\\
        -   \&    -        \&   -        \&               \&   +         \&   +        \& +\\
      };
      \draw[blue,thick] (A-1-2.center) -- (A-4-5.center);
      \draw[blue,thick] (A-1-3.center)  -- (A-4-6.center);
      \draw[blue,thick] (A-1-4.center) -- (A-4-7.center);
      \draw[red,thick,->] (A-1-6.center) -- (A-4-3.center);
      \draw[red,thick,->] (A-1-5.center) -- (A-4-2.center);
      \draw[red,thick,->] (A-1-4.center) -- (A-4-1.center);
    \end{tikzpicture}
    \caption{沙路法}
  \end{figure}

\end{document}