Center overfull subfloats

Question

I have some plots that I want to group together into one figure as subfigures using subfloat. I want to align them as two per row but it seems they are too big (Overfull \hbox). Nonetheless I want them to be on one row and be centered which means they should have the same distance to the left and right border of the sheet.

The following code is a stripped down version of one of my figures and exhibits the problem.

\documentclass[a4paper,10pt]{scrreprt}
\usepackage{pgfplots}
\usepackage{subfig}
\usepackage{blindtext}

\begin{document}
\begin{figure}
\centering
\subfloat[]{
\begin{tikzpicture}
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
\subfloat[]{
\begin{tikzpicture}
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
\end{figure}
\blindtext
\end{document}

As you can see in the resulting page, the figures are much closer to the right border than to the left.

I don't seem to be able to move them in any way. As you can see I tried \centering and I also have tried \subfloatrow to no avail.

Answer 1

Use \makebox to set the "official width" to zero. This will remove the overfull \hbox warning (because TeX now considers the images to be zero points wide) and also center the box:

\documentclass[a4paper,10pt]{scrreprt}
\usepackage{pgfplots}
\usepackage{subfig}
\usepackage{blindtext}

\begin{document}
\begin{figure}
\centering
\makebox[0pt]{
\subfloat[]{
\begin{tikzpicture}
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
\subfloat[]{
\begin{tikzpicture}
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
}
\end{figure}
\blindtext
\end{document}

Answer 2

Do you want to resize or just shift them? You can easily resize them to \textwidth using \resizebox{\textwidth}{!}{ } (inside the figure environment), IMHO it would look better that way.

\documentclass[a4paper,10pt]{scrreprt}
\usepackage{pgfplots}
\usepackage{subfig}
\usepackage{blindtext}

\begin{document}

\begin{figure}
\resizebox{\textwidth}{!}{
\subfloat[]{
\begin{tikzpicture}
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
\subfloat[]{
\begin{tikzpicture}
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
}
\end{figure}

\blindtext

\end{document}

Here's a sample code for shifting, with the use subcaption as Donut E. Knot mentioned in his comment, it would be better than subfloat. This should get you started.

\documentclass[a4paper,10pt]{scrreprt}
\usepackage{pgfplots}
\usepackage{subcaption}
\usepackage{subfig}
\usepackage{blindtext}

\newsavebox{\mybox}

\newlength{\boxwidth}

\newenvironment{myenv}{%
    \begin{lrbox}{\mybox}%
}{%
    \end{lrbox}%
    \setlength{\boxwidth}{\the\wd\mybox}%
    \addtolength{\boxwidth}{-\textwidth}%
    \hspace*{-0.5\boxwidth}\makebox[\the\wd\mybox][c]{%
        \usebox{\mybox}%
    }%
}

\begin{document}
\blindtext
\begin{figure}[hbtp]
  \begin{myenv}
    \begin{subfigure}[c]{0.6\textwidth}
            \begin{tikzpicture}
                    \begin{axis}[]
                    \end{axis}
            \end{tikzpicture}
            \caption{Left figure}
            \label{fig:Left}
    \end{subfigure}
    \qquad
    \begin{subfigure}[c]{0.6\textwidth}
            \centering
            \begin{tikzpicture}
                    \begin{axis}[]
                    \end{axis}
            \end{tikzpicture}
            \caption{Right figure}
            \label{fig:Right}
    \end{subfigure}
  \end{myenv}
  \caption{Left and right figures side by side}
  \label{fig:Group}
\end{figure}
\blindtext
\end{document}

Answer 3

A recommended solution with subcaption.

\documentclass[preview,border=12pt]{standalone}% change it back to your document class
\usepackage{pgfplots}
\usepackage{subcaption}
\usepackage{blindtext}

\begin{document}
\blindtext
\begin{figure}[hbtp]
    \centering
    \subfigure[c]{.4\linewidth}
            \centering
            \begin{tikzpicture}[scale=0.6]
                    \begin{axis}[]
                    \end{axis}
            \end{tikzpicture}
            \caption{Left figure}
            \label{fig:Left}
    \endsubfigure
    \qquad
    \subfigure[c]{.4\linewidth}
            \centering
            \begin{tikzpicture}[scale=0.6]
                    \begin{axis}[]
                    \end{axis}
            \end{tikzpicture}
            \caption{Right figure}
            \label{fig:Right}
    \endsubfigure
    \caption{Left and right figures side by side}
    \label{fig:Group}
\end{figure}
\blindtext
\end{document}

Answer 4

Try to use scale option for tikzpicture as shown in code below:

\documentclass[a4paper,10pt]{scrreprt}
\usepackage{pgfplots}
\usepackage{subfig}
\usepackage{blindtext}

\begin{document}
\begin{figure}
\centering
\subfloat[]{
\begin{tikzpicture}[scale=0.7]
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
\subfloat[]{
\begin{tikzpicture}[scale=0.7]
\begin{axis}[]
\end{axis}
\end{tikzpicture}
}
\end{figure}
\blindtext
\end{document}