在方程环境中缩放和定位 TikZ 图形

Question

我正在尝试将 TikZ 图形用作方程的一部分，但我只能使定位或缩放正确显示。

例如，使用“resizebox”为我的图形提供正确的大小使它们显示如下（放大以便于查看）：

如果我指定基线，则似乎会跳过调整大小。

\documentclass{standalone}
\usepackage{amsmath}
\usepackage{tikz}
    \usetikzlibrary{calc}
\newcommand{\leftribbon}{%
\resizebox{!}{10pt}{
\begin{tikzpicture}%[baseline={($ (current bounding box) - (0,0pt) $)}]
        \node (start) at (0,1) {};
        \node (end) at (1,1) {};
        \node (bottom) at (0.5,0) {};

        \path[color=black, line width=2pt] [out=180, in=-135] (bottom.center) edge (end.west);
        \path[color=white, line width=6pt] [out=-45, in=0] (start.east) edge (bottom.center);
        \path[color=black, line width=2pt] [out=-45, in=0] (start.east) edge (bottom.center);
\end{tikzpicture}
}%
}

\newcommand{\rightribbon}{%
\resizebox{!}{10pt}{
\begin{tikzpicture}%[baseline={($ (current bounding box) - (0,0pt) $)}]
\begin{scope}[xscale=-1]
    \node (start) at (0.3,1) {};
    \node (end) at (0.7,1) {};
    \node (bottom) at (0.5,0) {};

    \path[color=black, line width=2pt] [out=180, in=-135] (bottom.center) edge (end.west);
    \path[color=white, line width=6pt] [out=-45, in=0] (start.east) edge (bottom.center);
    \path[color=black, line width=2pt] [out=-45, in=0] (start.east) edge (bottom.center);
\end{scope}
\end{tikzpicture}
}%
}

\newcommand{\ribcup}{%
\resizebox{!}{10pt}{
\begin{tikzpicture}%[baseline={($ (current bounding box) - (0,0pt) $)}]
\begin{scope}[xscale=1]
    \node (start) at (-0.5,1) {};
    \node (end) at (0.5,1) {};
    \node (bottom) at (0,0) {};

    \path[color=black, line width=2pt] [out=0, in=-135] (bottom.center) edge (end.west);
    \path[color=black, line width=2pt] [out=-45, in=180] (start.east) edge (bottom.center);
\end{scope}
\end{tikzpicture}
}%
}

\begin{document}
    \[  \langle \leftribbon \rangle = -A^3\langle\ribcup\rangle \]
\end{document}

Answer 1

要回答您的问题，您只需使用baseline如下方法：

\newcommand{\leftribbon}{%
\resizebox{!}{10pt}{
\begin{tikzpicture}[baseline]
        \node[inner sep=0pt] (start) at (0,1) {};
        \node[inner sep=0pt] (end) at (1,1) {};
        \node[inner sep=0pt] (bottom) at (0.5,0) {};

        \path[color=black, line width=2pt] [out=180, in=-135] (bottom.center) edge (end.west);
        \path[color=white, line width=6pt] [out=-45, in=0] (start.east) edge (bottom.center);
        \path[color=black, line width=2pt] [out=-45, in=0] (start.east) edge (bottom.center);
\end{tikzpicture}
}%
}

在你的情况下你需要添加.base例如这样的：

\newcommand{\leftribbon}{%
\resizebox{!}{10pt}{
\begin{tikzpicture}[baseline= {($(current bounding box.base)-(-2pt,-2pt)$)}]
        \node[inner sep=0pt] (start) at (0,1) {};
        \node[inner sep=0pt] (end) at (1,1) {};
        \node[inner sep=0pt] (bottom) at (0.5,0) {};

        \path[color=black, line width=2pt] [out=180, in=-135] (bottom.center) edge (end.west);
        \path[color=white, line width=6pt] [out=-45, in=0] (start.east) edge (bottom.center);
        \path[color=black, line width=2pt] [out=-45, in=0] (start.east) edge (bottom.center);
\end{tikzpicture}
}%
}

我更新了您的代码，并删除了\resizebox（我认为这里没有必要）首先：如果您愿意，这里比您需要添加的coordinate更好。我添加了一些样式以轻松修改结果。nodeinner sep=0pt

\documentclass{article}
\usepackage{amsmath}
\usepackage{tikz}
\usetikzlibrary{calc}

\tikzset{char/.style = { color=black,line width=.6pt}}
\tikzset{effet/.style = { color=white,line width=1.2pt}} 

\newcommand{\leftribbon}[1][1]{%
\begin{tikzpicture}[baseline,scale=#1]
        \coordinate (start) at (0,10pt) ;
        \coordinate (end) at (10pt,10pt) ;
        \coordinate (bottom) at (5pt,0) ;

        \draw[char] [out=180, in=-135] (bottom.center) edge (end.west);
        \draw[effet] [out=-45, in=0] (start.east) edge (bottom.center);
        \draw[char] [out=-45, in=0] (start.east) edge (bottom.center);
\end{tikzpicture}
}%  


\newcommand{\rightribbon}[1][1]{%    
\begin{tikzpicture}[baseline,scale=#1]  
\begin{scope}[xscale=-1]
    \coordinate (start) at (3pt,10pt);
    \coordinate (end) at (7pt,10pt) ;
    \coordinate (bottom) at (5pt,0);

    \draw[char] [out=180, in=-135] (bottom.center) edge (end.west);
    \draw[effet] [out=-45, in=0] (start.east) edge (bottom.center);
    \draw[char] [out=-45, in=0] (start.east) edge (bottom.center);
\end{scope}
\end{tikzpicture}
}%


\newcommand{\ribcup}[1][1]{%    
\begin{tikzpicture}[baseline,scale=#1]
    \coordinate (start) at (-5pt,10pt) ;
    \coordinate (end) at (5pt,10pt) ;
    \coordinate (bottom) at (0pt,0pt);

    \path[char] [out=0, in=-135] (bottom.center) edge (end.west);
    \path[char] [out=-45, in=180] (start.east) edge (bottom.center);
\end{tikzpicture}
}%


\begin{document}
     \[
      \langle \leftribbon[.8]\rangle = -A^3   \langle\ribcup[.8]\rangle
    \]  
\end{document}