# pgfplots - Provide a detailed plot inside the main plot

I have a main plot and inside it I would like to add a smaller plot that offers a higher level of detail.

A rough illustration of the above is:

Notice that the smaller plot provides a more detailed evolution of the blue curve when the latter approaces the x-axis.

How can I do that using the pgfplots package?

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Is zooming in a valid option? If so you can try the spy library of TikZ. –  percusse Mar 2 '13 at 15:12
@percusse unfortunately the spy library isn't suitable (just saw some examples in www.texample.net) for this particular need. Thanks though. –  niels Mar 2 '13 at 15:20

I'm not sure why the spy library isn't suitable, but you can achieve what you want by using

\newsavebox{\mybox}
\savebox{\mybox}{%
<code for miniature figure>
}


and then \usebox{\mybox} at an appropriate place on the axis. Note that you can't use a node directly as pgfplots won't allow you to nest axis.

% arara: pdflatex
\documentclass{standalone}
\usepackage{pgfplots}

\begin{document}

\newsavebox{\mybox}
\savebox{\mybox}{%
\begin{tikzpicture}
\begin{axis}[xmin=0,xmax=25,
ymin=0,ymax=1,
grid=both,
width=6cm,
height=3cm]
\end{axis}
\end{tikzpicture}
}

\begin{tikzpicture}
\begin{axis}[xmin=0,xmax=25,
ymin=0,ymax=1,
grid=both]
\draw (axis cs: 13,.4)node{\usebox{\mybox}};
\end{axis}
\end{tikzpicture}

\end{document}

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gee thanks @cmhughes!! As per the spy library, I got the idea (obviously wrong) from the examples and www.texample.com that the miniature would be located outside the main plot. –  niels Mar 2 '13 at 21:02
you can add the axis property axis background/.style={fill=white} so that the grid lines of the two plots do not mix. –  niels Mar 2 '13 at 21:28
Nice solution. However, I noticed that the second plot will always be inside the main plot area, which crops the xtick/ytick labels when I place it near the edge. Is there a way to overcome this? –  joaocandre Jul 17 '13 at 16:04
@joaocandre I suppose you could move the ticks, or make them smaller, or just have a whole other subplot... –  cmhughes Jul 17 '13 at 17:28
first of all let me admit that this is very nice work. However I have a question. Although i managed to implement this correctly and looks fine within LaTeX, when i try to export the image as a pdf using the externalize command, I get 2 discrete image-pdf's rather than a single pdf. Any ideas? –  sonakis Nov 18 '13 at 10:21