括号中的图形标签

Question

我使用以下代码显示四个图形。编译时，我得到每个图形的标签为 a、b、c 和 d。我希望这些标签用括号显示为 (a)、(b)、(c) 和 (d)。我该怎么做？

\begin{figure*}[ht] 
    \begin{subfigure}[b]{0.5\linewidth}
        \centering
        \includegraphics[width=0.75\linewidth]{figure_a} 
            \caption{}
        \label{fig7:a} 
        \vspace{4ex}
    \end{subfigure}%% 
    \begin{subfigure}[b]{0.5\linewidth}
        \centering
        \includegraphics[width=0.75\linewidth]{figure_b} 
        \caption{} 
        \label{fig7:b} 
        \vspace{4ex}
    \end{subfigure} 
    \begin{subfigure}[b]{0.5\linewidth}
        \centering
        \includegraphics[width=0.75\linewidth]{figure_c} 
        \caption{} 
        \label{fig7:c} 
    \end{subfigure}%%
    \begin{subfigure}[b]{0.5\linewidth}
        \centering
        \includegraphics[width=0.75\linewidth]{figure_d} 
        \caption{} 
        \label{fig7:d} 
    \end{subfigure} 
    \caption{My caption }
    \label{myfig}
\end{figure*}

Answer 1

这是subcaption包裹：

\documentclass{article}

\usepackage{graphicx,subcaption}

\begin{document}

\begin{figure*}[ht] 
  \begin{subfigure}[b]{0.5\linewidth}
    \centering
    \includegraphics[width=0.75\linewidth]{example-image-a} 
    \caption{}
  \end{subfigure}%% 
  \begin{subfigure}[b]{0.5\linewidth}
    \centering
    \includegraphics[width=0.75\linewidth]{example-image-b} 
    \caption{} 
  \end{subfigure} 
  \begin{subfigure}[b]{0.5\linewidth}
    \centering
    \includegraphics[width=0.75\linewidth]{example-image-c} 
    \caption{} 
  \end{subfigure}%%
  \begin{subfigure}[b]{0.5\linewidth}
    \centering
    \includegraphics[width=0.75\linewidth]{example-image-a} 
    \caption{} 
  \end{subfigure}
  \caption{My caption}
\end{figure*}

\end{document}

可以使用以下功能修改上述样式caption（因为它是由同一位作者写的）。