在tikz中将一个节点相对于另一个节点的中心定位

Question

如何将节点“s2”定位在“s1”上方，以便最左边的 0（节点“s2”）正好位于“s1”的上方和中心

\documentclass{beamer}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}

\begin{frame}
  \begin{tikzpicture}[overlay,remember picture]
    \node[draw,fill=cyan!40,minimum size=1.2cm,rectangle,yshift=.5cm] at (current page.center) 
    (s1) {q};

    \node[draw=none,above=of s1,anchor=south west] (s2) {0 0 0 1 1 1};
    \draw[->] (s1) -- (s2);
  \end{tikzpicture}
\end{frame}
\end{document}

Answer 1

一种方法是将节点锚定在西南方向（如您所做的那样），然后将其向左移动必要的量以对齐第一个零：

\documentclass{beamer}
\usepackage{tikz}
\usepackage{calc}
\usetikzlibrary{positioning}
\begin{document}

\newlength{\zerooffset}
\begin{frame}
  \begin{tikzpicture}[overlay,remember picture]
    \node[draw,fill=cyan!40,minimum size=1.2cm,rectangle,yshift=.5cm] at (current page.center) 
    (s1) {q};
    \setlength{\zerooffset}{\widthof{0}}%<=== get the width of the 0
    \node[draw=none,above= of s1,anchor=south west,xshift={\dimexpr-0.5\zerooffset-\pgfkeysvalueof{/pgf/inner xsep}}] (s2) {0 0 0 1 1 1};
    \draw[->] (s1) -- (s2);
  \end{tikzpicture}
\end{frame}
\end{document}

如果您希望箭头垂直：

\documentclass{beamer}

\usepackage{tikz}
\usepackage{calc}
\usetikzlibrary{positioning}
\usetikzlibrary{calc}
\begin{document}

\newlength{\zerooffset}
\begin{frame}
  \begin{tikzpicture}[overlay,remember picture]
    \node[draw,fill=cyan!40,minimum size=1.2cm,rectangle,yshift=.5cm] at (current page.center) 
    (s1) {q};
    \setlength{\zerooffset}{\widthof{0}}%<=== get the width of the 0
    \node[draw=none,above= of s1,anchor=south west,xshift={\dimexpr-0.5\zerooffset-\pgfkeysvalueof{/pgf/inner xsep}}] (s2) {0 0 0 1 1 1};
    \draw[->] let \p1=(s1.north),\p2=(s2.south) in (\x1,\y1)--(\x1,\y2);%<=== vertical arrow
  \end{tikzpicture}
\end{frame}
\end{document}

Answer 2

试试这个。我把包含文本的节点分成了两个，这样就可以根据需要定位它们。注意\smallskipamount对应于零之间的空格。

代码：

\documentclass{beamer}
\usepackage{tikz}
\usetikzlibrary{positioning}
\begin{document}
    \begin{frame}
        \begin{tikzpicture}[overlay,remember picture]
        \node[draw,fill=cyan!40,minimum size=1.2cm,rectangle,yshift=.5cm] at (current page.center) (s1) {q};

        \node[draw=none,above=of s1] (s2) {0};
        \node[draw=none,right=\smallskipamount] at (s2) {0 0 1 1 1};

        \draw[->] (s1) -- (s2);
        \end{tikzpicture}
    \end{frame}
\end{document}

结果：