# the problem about package subfloat

I want to insert couples of images which shares one caption into "subfloat",but I got an error, could anyone please help me with this problem? Here is my code:

\documentclass{article}
\usepackage{graphicx}
\usepackage{subfig}
\begin{document}
\begin{figure}
\centering
% Requires \usepackage{graphicx}
\begin{minipage}[t]{0.45\textwidth}
\centering
\subfloat[~$2\%$~lifetime sparsity]{
\includegraphics[width=0.05\textwidth]{figures/second/0_02/001.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/002.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/003.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/004.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/005.pdf}\\
\includegraphics[width=0.05\textwidth]{figures/second/0_02/006.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/007.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/008.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/009.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/010.pdf}\\
\includegraphics[width=0.05\textwidth]{figures/second/0_02/011.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/012.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/013.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/014.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/015.pdf}\\
\includegraphics[width=0.05\textwidth]{figures/second/0_02/016.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/017.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/018.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/019.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_02/020.pdf}
}
% \vspace{0.15in}
%\caption{~$2\%$~lifetime sparsity}\label{fig:ROI:fig2}
\end{minipage}
\begin{minipage}[t]{0.45\textwidth}
\centering
\subfloat[~$5\%$~lifetime sparsity]{
\includegraphics[width=0.05\textwidth]{figures/second/0_05/001.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/002.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/003.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/004.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/005.pdf}\\
\includegraphics[width=0.05\textwidth]{figures/second/0_05/006.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/007.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/008.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/009.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/010.pdf}\\
\includegraphics[width=0.05\textwidth]{figures/second/0_05/011.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/012.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/013.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/014.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/015.pdf}\\
\includegraphics[width=0.05\textwidth]{figures/second/0_05/016.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/017.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/018.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/019.pdf}\hspace{0.1in}
\includegraphics[width=0.05\textwidth]{figures/second/0_05/020.pdf}
}
%\vspace{0.15in}
%\caption{~$5\%$~lifetime sparsity}\label{fig:ROI:fig3}
\end{minipage}
\end{figure}
\end{document}


You should have the minipage inside \subfloat:

\documentclass{article}
\usepackage[demo]{graphicx}
\usepackage{subfig}
\begin{document}
\begin{figure}

\setkeys{Gin}{height=0.1\textwidth}% just for the example, remove

\centering

\subfloat[$2\%$~lifetime sparsity\label{fig:ROI:fig2}]{%
\begin{minipage}[t]{0.45\textwidth}
\centering
\includegraphics[width=0.1\textwidth]{figures/second/0_02/001.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/002.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/003.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/004.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/005.pdf}\\
\includegraphics[width=0.1\textwidth]{figures/second/0_02/006.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/007.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/008.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/009.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/010.pdf}\\
\includegraphics[width=0.1\textwidth]{figures/second/0_02/011.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/012.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/013.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/014.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/015.pdf}\\
\includegraphics[width=0.1\textwidth]{figures/second/0_02/016.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/017.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/018.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/019.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_02/020.pdf}
\end{minipage}%
}\hfil
\subfloat[~$5\%$~lifetime sparsity\label{fig:ROI:fig3}]{%
\begin{minipage}[t]{0.45\textwidth}
\centering
\includegraphics[width=0.1\textwidth]{figures/second/0_05/001.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/002.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/003.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/004.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/005.pdf}\\
\includegraphics[width=0.1\textwidth]{figures/second/0_05/006.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/007.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/008.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/009.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/010.pdf}\\
\includegraphics[width=0.1\textwidth]{figures/second/0_05/011.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/012.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/013.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/014.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/015.pdf}\\
\includegraphics[width=0.1\textwidth]{figures/second/0_05/016.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/017.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/018.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/019.pdf}
\includegraphics[width=0.1\textwidth]{figures/second/0_05/020.pdf}
\end{minipage}%
}

\caption{Global caption\label{fig:ROI}}
\end{figure}

\end{document}


The demo option and the \setkeys command are just for building an image, since I don't have your images.

• Great! Thank you! Your answer work very well. – Ellen Liu Apr 22 '17 at 11:47