如何获得超过 26 个子图？

Question

具有 6 个子图环境的代码会导致错误，但不会减少，因为我用完了子图的标签：a)、b)、...、n)，但我需要更多

\documentclass{article}
\usepackage[demo]{graphicx}
\usepackage{subcaption}
\usepackage{pgffor}

\begin{document}

\begin{figure}
\foreach \ii in {1,...,5}{
\centering% not \center!
\begin{subfigure}{0.19\textwidth}
  \centering
  \includegraphics[scale=0.11, page=\ii]{{Rplots.bland.male.5}.pdf}
  \caption{\#\ii, ite. 1.}
\end{subfigure}
\begin{subfigure}{0.19\textwidth}
  \centering
  \includegraphics[scale=0.11, page=\ii]{{Rplots.blandmale.6}.pdf}
  \caption{\#\ii, ite. 2.}
\end{subfigure}
\begin{subfigure}{0.19\textwidth}
  \centering
  \includegraphics[scale=0.11, page=\ii]{{Rplots.bland.male.7}.pdf}
  \caption{\#\ii, ite. 3.}
\end{subfigure}
\begin{subfigure}{0.19\textwidth}
  \centering
  \includegraphics[scale=0.11, page=\ii]{{Rplots.bland.8}.pdf}
  \caption{\#\ii, ite. 4.}
\end{subfigure}
\begin{subfigure}{0.19\textwidth}
  \centering
  \includegraphics[scale=0.11, page=\ii]{{Rplots.bland.9}.pdf}
  \caption{\#\ii, ite. 5.}
\end{subfigure}
\begin{subfigure}{0.19\textwidth}
  \centering
  \includegraphics[scale=0.11, page=\ii]{{Rplots.bland.10}.pdf}
  \caption{\#\ii, ite. 6.}
\end{subfigure}
}
\end{figure}
\end{document}

错误

! LaTeX Error: Counter too large.

See the LaTeX manual or LaTeX Companion for explanation.
Type  H <return>  for immediate help.
 ...                                              

l.1492 }

? 

TeXLive：2016年
操作系统：Debian 8.5

Answer 1

alphalph如果字母数量用尽，包提供了一些继续用字母编号的方法，例如：

\usepackage{alphalph}
\renewcommand*{\thesubfigure}{\alphalph{\value{subfigure}}}

完整示例：

\documentclass{article}
\usepackage{graphicx}
\usepackage{subcaption}
\usepackage{pgffor}

\usepackage{alphalph}
\renewcommand*{\thesubfigure}{\alphalph{\value{subfigure}}}

\begin{document}

\newcommand*{\img}{%
  \includegraphics[
    width=\linewidth,
    height=20pt,
    keepaspectratio=false,
  ]{example-image-a}%
}

\begin{figure}
\foreach \ii in {1,...,5}{%
  \centering
  \begin{subfigure}{0.19\textwidth}
    \centering
    \img
    \caption{\#\ii, ite. 1.}
  \end{subfigure}
  \begin{subfigure}{0.19\textwidth}
    \centering
    \img
    \caption{\#\ii, ite. 2.}
  \end{subfigure}
  \begin{subfigure}{0.19\textwidth}
    \centering
    \img
    \caption{\#\ii, ite. 3.}
  \end{subfigure}
  \begin{subfigure}{0.19\textwidth}
    \centering
    \img
    \caption{\#\ii, ite. 4.}
  \end{subfigure}
  \begin{subfigure}{0.19\textwidth}
    \centering
    \img
    \caption{\#\ii, ite. 5.}
  \end{subfigure}
  \begin{subfigure}{0.19\textwidth}
    \centering
    \img
    \caption{\#\ii, ite. 6.}
  \end{subfigure}
}%
\lastlinefit=1000 % same inter-image spaces in last line as in previous lines
\end{figure}

\end{document}

Answer 2

如果使用\alph或\Alph并且值超过 26，就会出现该错误。

如果需要更大的值，则需要不同的显示功能。