Common scale for pgfplots groupplot

The groupplots environment allows global values of xmax to be set. Is there a way to automatically select a common value for all plots in a group? For example, with the code below, the 4th plot does not have the same x-scale as the other 3 plots. Is it possible to have all 4 plots use the same x-axis without manually defining a maximum x value (in this case, '2')?

\documentclass{article}
\usepackage{pgfplots}
\usepgfplotslibrary{groupplots}
\begin{document}
\begin{tikzpicture}
\begin{groupplot}[group style={group size=2 by 2}]
\nextgroupplot
\nextgroupplot
\nextgroupplot
\nextgroupplot
\end{groupplot}
\end{tikzpicture}
\end{document}

-
You can achieve the same scale via axis equal=true, but that might not be exactly what you want as the last graph does not have the same xmin, xmax, but not sure if that is required. –  Peter Grill Nov 19 '12 at 11:05
That does provide the correct scale, but I was ultimately looking to use x descriptions at=edge bottom, which, with the example provided, provides the wrong axis labels for the second plot. –  mynoduesp Nov 19 '12 at 12:13

You can use the every plot/.style key to enter the common settings in that group

\documentclass{article}
\usepackage{pgfplots}
\usepgfplotslibrary{groupplots}
\begin{document}
\begin{tikzpicture}
\begin{groupplot}[group style={group size=2 by 2,
every plot/.style={
xmin=-1,
xmax=2,
enlargelimits=true
}
}]
\nextgroupplot
\nextgroupplot

@mynoduesp Then we need to harvest all the xmax values from each plot and choose the largest one. I'll try to see if I can find something but I don't have much hope. –  percusse Nov 19 '12 at 13:16