为什么'％'符号会影响子图对齐？

Question

这两个 LaTeX 片段仅在子图 1 末尾的 '%' 符号上有所不同，但它们产生的子图对齐方式不同：

片段 1（不含“%”符号）：

\begin{figure*}
    \centering
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1a_line.pdf}
        \caption{Subfigure 1}
    \end{subfigure}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1a_region.png}
        \caption{Subfigure 2}
    \end{subfigure}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1b_line.pdf}
        \caption{Subfigure 3}
    \end{subfigure}
    \hspace{0mm}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1a_region.png}
        \caption{Subfigure 4}
    \end{subfigure}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1c_line.pdf}
        \caption{Subfigure 5}
    \end{subfigure}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1c_region.png}
        \caption{Subfigure 6}
    \end{subfigure}
    % \caption{Stability analysis of example \ref{example:compound}}
    \caption{Hello}
\end{figure*}

片段 1（带有'％'符号）：

\begin{figure*}
    \centering
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1a_line.pdf}
        \caption{Subfigure 1}
    \end{subfigure}%
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1a_region.png}
        \caption{Subfigure 2}
    \end{subfigure}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1b_line.pdf}
        \caption{Subfigure 3}
    \end{subfigure}
    \hspace{0mm}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1a_region.png}
        \caption{Subfigure 4}
    \end{subfigure}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1c_line.pdf}
        \caption{Subfigure 5}
    \end{subfigure}
    \begin{subfigure}[b]{0.33\textwidth}
        \centering
        \includegraphics[width=\textwidth]{example1c_region.png}
        \caption{Subfigure 6}
    \end{subfigure}
    % \caption{Stability analysis of example \ref{example:compound}}
    \caption{Hello}
\end{figure*}

为什么“％”符号会影响子图的位置？

Answer 1

一些一般性评论：

• \centering每个环境的7条指令figure*没有任何用处；请删除它们。

• OP 的第一个figure*环境每行仅显示两个子图，而不是三个。这是因为每个子图后面的隐式空格\end{subfigure}被允许保留。在 OP 的第二个环境中情况并非如此figure*。

无论如何，我认为您的浮动真正需要的是每行一些位置合适的\hfill指令，以及相对子图宽度的轻微减少，从0.33\textwidth到0.32\textwith。

\documentclass[twocolumn,demo]{article} % remove 'demo' option in real document
\usepackage{graphicx,subcaption}
\begin{document}

\begin{figure*}
\captionsetup[subfigure]{skip=0.25\baselineskip}

    \begin{subfigure}[b]{0.32\textwidth}
      \includegraphics[width=\textwidth]{example1a_line.pdf}
      \caption{Subfigure 1}
    \end{subfigure}\hfill
    \begin{subfigure}[b]{0.32\textwidth}
      \includegraphics[width=\textwidth]{example1a_region.png}
      \caption{Subfigure 2}
    \end{subfigure}\hfill
    \begin{subfigure}[b]{0.32\textwidth}
      \includegraphics[width=\textwidth]{example1b_line.pdf}
      \caption{Subfigure 3}
    \end{subfigure} % keep the next line blank to force a line-break
    
    \medskip
    \begin{subfigure}[b]{0.32\textwidth}
      \includegraphics[width=\textwidth]{example1a_region.png}
      \caption{Subfigure 4}
    \end{subfigure}\hfill
    \begin{subfigure}[b]{0.32\textwidth}
      \includegraphics[width=\textwidth]{example1c_line.pdf}
      \caption{Subfigure 5}
    \end{subfigure}\hfill
    \begin{subfigure}[b]{0.32\textwidth}
      \includegraphics[width=\textwidth]{example1c_region.png}
      \caption{Subfigure 6}
    \end{subfigure}
    
    \caption{Stability analysis}
    \label{example:compound}
\end{figure*}

\end{document}

Answer 2

尝试这个：

\documentclass{article} 

\usepackage{subcaption}
\usepackage{graphicx}

\begin{document}

\begin{figure*}
    \centering
    \begin{subfigure}[b]{0.325\textwidth}
        \centering
        \includegraphics[width=\linewidth]{a.png}
        \caption{Subfigure 1}
    \end{subfigure}
    \begin{subfigure}[b]{0.325\textwidth}
        \centering
        \includegraphics[width=\linewidth]{a.png}
        \caption{Subfigure 2}
    \end{subfigure}
    \begin{subfigure}[b]{0.325\textwidth}
        \centering
        \includegraphics[width=\linewidth]{a.png}
        \caption{Subfigure 3}
    \end{subfigure}
    \vskip\floatsep
    \begin{subfigure}[b]{0.325\textwidth}
        \centering
        \includegraphics[width=\linewidth]{a.png}
        \caption{Subfigure 4}
    \end{subfigure}
    \begin{subfigure}[b]{0.325\textwidth}
        \centering
        \includegraphics[width=\linewidth]{a.png}
        \caption{Subfigure 5}
    \end{subfigure}
    \begin{subfigure}[b]{0.325\textwidth}
        \centering
        \includegraphics[width=\linewidth]{a.png}
        \caption{Subfigure 6}
    \end{subfigure}
    % \caption{Stability analysis of example \ref{example:compound}}
    \caption{Hello}
\end{figure*}


\end{document}