将二维数组的索引移动到行的左侧

Question

我正在尝试绘制一个二维数组，索引位于每行开头的框上方。有人能帮我把它们放在行的左边吗？

任何帮助是极大的赞赏！

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc, chains, positioning}

\begin{document}

\begin{tikzpicture}[
node distance = 6mm and 1mm,
  start chain = going below,
   box/.style = {draw, minimum size=8mm, on chain}
                ]
\node (n11) [box, label=0] {2};
\node       [box, label=1] {1};
\node       [box, label=2] {-9};
%
\begin{scope}[every node/.style={box}]
\node (n21) [right=of n11]  {4};
\node       {3};
\node       {-8};
%
\node (n31)  [right=of n21]  {6};
\node       {5};
\node       {-7};
%
\node (n41) [right=of n31] {8};
\node       {7};
\node       {-6};
%
    \end{scope}
  \end{tikzpicture}

\end{document}

Answer 1

既然你正在编写一个数组，为什么不使用\matrix？

如果您有一个包含多行的矩阵并且编写标签很无聊，那么您可以使用\foreach。

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{matrix}
\tikzset{
    box/.style = {draw, minimum size=8mm},
}

\begin{document}
    Matrix with labelled nodes:
    \begin{center}
    \begin{tikzpicture}[label distance=-4pt]
        \matrix[
            column sep = 1mm,
            row sep = 6mm,
            matrix of math nodes,
            nodes={box},
            ] (M) {
            |[label=left:0]|2 & 4 & 6 & 8 \\
            |[label=left:1]|1 & 3 & 5 & 7 \\
            |[label=left:2]|-9 & -8 & -7 & -6 \\
            };
    \end{tikzpicture}
    \end{center}
    Matrix with labels set by a \texttt{\textbackslash foreach}:
    \begin{center}
    \begin{tikzpicture}
        \matrix[
            column sep = 1mm,
            row sep = 6mm,
            matrix of math nodes,
            nodes={box},
            ] (M) { 
                2 & 4 & 6 & 8 \\
                1 & 3 & 5 & 7 \\
                -9 & -8 & -7 & -6 \\
            };
        \foreach \i [evaluate=\i as \j using {int(\i-1)}] in {1,2,3}
            \node at ([xshift=-2em]M-\i-1) {\j};
    \end{tikzpicture}
    \end{center}
\end{document}

Answer 2

您只需要声明标签位置。如果没有这个，则假定标签位于节点上方：

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc, chains, positioning}

\begin{document}
    \begin{tikzpicture}[
node distance = 6mm and 1mm,
  start chain = going below,
   box/.style = {draw, minimum size=8mm, on chain}
                ]
\node (n11) [box, label=left:0] {2};
\node       [box, label=left:1] {1};
\node       [box, label=left:2] {-9};
%
\begin{scope}[every node/.style={box}]
\node (n21) [right=of n11]  {4};
\node       {3};
\node       {-8};
%
\node (n31)  [right=of n21]  {6};
\node       {5};
\node       {-7};
%
\node (n41) [right=of n31] {8};
\node       {7};
\node       {-6};
%
    \end{scope}
  \end{tikzpicture}
\end{document}

你将获得：

Answer 3

这样怎么样？

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{calc, chains, positioning}

\begin{document}

\begin{tikzpicture}[
node distance = 6mm and 1mm,
  start chain = going below,
   box/.style = {draw, minimum size=8mm, on chain}
                ]
\node (n11) [box] {2};
\node       [left= of n11] {0};
\node (L1)  [box] {1};
\node (L2)  [box] {-9};
%
\begin{scope}[every node/.style={box}]
\node (n21) [right=of n11] {4};
\node       {3};
\node       {-8};
%
\node (n31) [right=of n21] {6};
\node       {5};
\node       {-7};

%
\node (n41) [right=of n31] {8};
\node       {7};
\node       {-6};
%
\end{scope}

\node       [left = of L1] {1};
\node       [left = of L2] {2};

\end{tikzpicture}

\end{document}