[Tex/LaTex] AIP conference proceedings template – placing subfigures vertically

Question

I am using the AIP conference proceedings class file (aip-cp.cls) for writing a paper. I want to place two subfigures vertically, one below the other, using the subcaption package. The following is a code similar to what I had used :

\documentclass{aip-cp}
\usepackage{graphicx}
\usepackage{subcaption}
\graphicspath{{./Figures/}}

\begin{document}
\title{Test}

\begin{figure}
\captionsetup{type=figure}
    \begin{subfigure}[b]{0.5\textwidth}
        \includegraphics[width=\textwidth]{ScatteringAmplitude.png}
    \end{subfigure}\\
    \begin{subfigure}[b]{0.5\textwidth}
        \includegraphics[width=\textwidth]{ScatteringAmplitude.png}
    \end{subfigure} 
\end{figure}

\end{document}

I used \captionsetup in the above code because aip-cp class defines its own figure environment, and therefore the subcaption package does not recognize the figure as a floating environment as explained in an answer to this question.

The problem is that the two subfigures appear side by side despite of using \\ or \newline. I do not face this problem when I use the article class however. I believe that the problem is in the aip-cp class, but as I am new to latex I don't know if it is possible to edit it to solve my problem.

The aip-cp class can be downloaded from here. I would appreciate if someone can go through the aip class file and let me know how to edit it. I am also happy with any alternate solution.

PS: I have also tried to use \subfloat from the subfig package, but the output was still the same.

Answer 1

The class is definitely not compatible with caption (and so also subcaption). It also redefines the figure environment in such a way that fools \subfloat from subfig into thinking that it is not in a floating environment.

Here's a suggestion for making subfig work, but I'd not be surprised if the copy editor of your submission will not be happy with it.

\documentclass{aip-cp}
\usepackage{graphicx}
\usepackage[caption=false]{subfig}
\graphicspath{{./Figures/}}

\makeatletter
\newenvironment{subfigures}
 {\begin{minipage}{\columnwidth}\def\@captype{figure}\centering}
 {\end{minipage}}
\makeatother

\begin{document}
\title{Test}

\begin{figure}

\begin{subfigures}
\subfloat[]{\includegraphics[width=0.5\textwidth]{example-image-a}}

\subfloat[]{\includegraphics[width=0.5\textwidth]{example-image-b}}
\end{subfigures}

\caption{This is the caption}

\end{figure}

\end{document}