[Tex/LaTex] Reduce space between figures in tabular

Question

I have arranged 4 plots using tabular. Now I try to decrease the space between the rows to move the plots and the labels closer together.

In another post (Column and row padding in tables) I read I should use

 {\renewcommand{\arraystretch}{1}%

However this is only working to a fixed lower bound (0.5 or something). I would like to decrease the space even more.

Here is a simplified example:

\documentclass[]{article}
\usepackage{graphicx}
\usepackage{tikz}

\begin{document}

\begin{figure}
  \small
  \begin{tabular}{cc}
    \input{top_left_figure.tex} & \input{top_right_figure.tex} \\
    (a) Sub figure 1 & (b)  Sub figure 2 \\
    \input{bottom_left_figure.tex} & \input{bottom_right_figure.tex} \\
    (c)  Sub figure 3 & (d)  Sub figure 4
\end{tabular} 
\caption{My title}
\end{figure}

\end{document}

Answer 1

I suggest you not use a tabular environment to accomplish your formatting objective. Instead, consider loading the subcaption package and using four subfigure environments inside the figure environment.

A notable advantage of this approach is that you can use LaTeX's \label-\ref cross-referencing mechanism for individual subfigures as well as for the figure as a whole.

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

\begin{document}

\begin{figure}
\captionsetup{size=small}

\begin{subfigure}{0.45\textwidth}
\includegraphics[width=\linewidth]{top_left_figure} 
\caption{Subfigure 1} \label{fig:4picsa}
\end{subfigure} 
\hfill
\begin{subfigure}{0.45\textwidth}
\includegraphics[width=\linewidth]{top_right_figure}
\caption{Subfigure 2} \label{fig:4picsb}
\end{subfigure}

\bigskip
\begin{subfigure}{0.45\textwidth}
\includegraphics[width=\linewidth]{bottom_left_figure}
\caption{Subfigure 3} \label{fig:4picsc}
\end{subfigure}
\hfill
\begin{subfigure}{0.45\textwidth}
\includegraphics[width=\linewidth]{bottom_right_figure}
\caption{Subfigure 4} \label{fig:4picsd}
\end{subfigure}

\caption{My title} \label{fig:4pics}
\end{figure}

\noindent
A cross-reference to Figure~\ref{fig:4pics}. Cross-references to Subfigures~\ref{fig:4picsa} and~\ref{fig:4picsd}.

\end{document}