pgfplots and figure centering

Question

I'm wondering about a way to exclude the axis labels and axis graduation from how latex will center the figure with respect to the caption. Labels and graduation along the y-axis (assuming it lies on the left of the figure) will tend to move the rest of the content to the right. I feel like it looks better when only the "main" content serves for centering purposes. Is such feature available?

Answer 1

Using pgf 2.10, you can provide the arguments trim axis left and trim axis right to the tikzpicture environment:

\documentclass{article}
\usepackage{pgfplots}

\begin{document}

\centering
\begin{tikzpicture}[trim axis left, trim axis right]
  \begin{axis}[ylabel={$y$},
    xlabel={$x$}]
    \addplot {x^2};
 \end{axis}
\end{tikzpicture}

(a)

\bigskip \bigskip

\begin{tikzpicture} % Example of leaving this out
  \begin{axis}[ylabel={$y$},
    xlabel={$x$}]
    \addplot {x^2};
  \end{axis}
\end{tikzpicture}

(a)

\end{document}

gives

This works without disturbing the bounding box for the purposes of image externalisation and so forth (avoiding some of the problems discussed in @Martin's earlier question).