How to add axes in a magnified part of a graph using spy?

Question

My problem is the following. I would like to draw the (magnified) axes on the magnified area of spy. For instance, take the following example (from pgfplots.pdf, p.121):

% Preamble: \pgfplotsset{width=7cm,compat=1.5.1}
% requires \usetikzlibrary{spy} 
\begin{tikzpicture}[spy using outlines=
{circle, magnification=6, connect spies}]
\begin{axis}[no markers,grid=major,
every axis plot post/.append style={thick}]
\addplot  coordinates
{(0, 0.0) (0, 0.9) (1, 0.9) (2, 1) (3, 0.9) (80, 0)};
\addplot +[line join=round] coordinates
{(0, 0.0) (0, 0.9) (2, 0.9) (3, 1) (4, 0.9) (80, 0)};
\addplot +[line join=bevel] coordinates
{(0, 0.0) (0, 0.9) (3, 0.9) (4, 1) (5, 0.9) (80, 0)};
\addplot +[miter limit=5] coordinates
{(0, 0.0) (0, 0.9) (4, 0.9) (5, 1) (6, 0.9) (80, 0)};
\coordinate (spypoint) at (axis cs:3,1);
\coordinate (magnifyglass) at (axis cs:60,0.7);
\end{axis}
\spy [blue, size=2.5cm] on (spypoint)
in node[fill=white] at (magnifyglass);
\end{tikzpicture}

I would like to draw axes (with a new grid) in the magnifyglass to see (approximately) the peak values in (x,y). Kind of like the "Loupe" tool in the DataGraph software. Is this possible?

Answer 1

Remarks

Using the question linked by Christian Feuersänger, I was able to produces an example.

Code

\documentclass[tikz]{standalone}
\usepackage{pgfplots}
\pgfplotsset{width=7cm,compat=1.5.1}
\usetikzlibrary{spy}
\begin{document}
\begin{tikzpicture}[every pin/.style={fill=white}]
    \begin{axis}[
            no markers,
            grid=major,
            every axis plot post/.append style={thick}
        ]
        \addplot  coordinates {(0, 0.0) (0, 0.9) (1, 0.9) (2, 1) (3, 0.9) (80, 0)};
        \addplot +[line join=round] coordinates {(0, 0.0) (0, 0.9) (2, 0.9) (3, 1) (4, 0.9) (80, 0)};
        \addplot +[line join=bevel] coordinates {(0, 0.0) (0, 0.9) (3, 0.9) (4, 1) (5, 0.9) (80, 0)};
        \addplot +[miter limit=5] coordinates {(0, 0.0) (0, 0.9) (4, 0.9) (5, 1) (6, 0.9) (80, 0)};
        \coordinate (spypoint) at (axis cs:3,1);
    \end{axis}
    \node[pin={[pin distance=1.5cm]357:{%
        \begin{tikzpicture}[baseline,trim axis left,trim axis right]
            \begin{axis}[
                    no markers,
                    grid=major,
                    every axis plot post/.append style={thick},
                    tiny,
                    xmin=1,xmax=6,
                    ymin=0.95,ymax=1.02,
                ]
                \addplot  coordinates {(0, 0.0) (0, 0.9) (1, 0.9) (2, 1) (3, 0.9) (80, 0)};
                \addplot +[line join=round] coordinates {(0, 0.0) (0, 0.9) (2, 0.9) (3, 1) (4, 0.9) (80, 0)};
                \addplot +[line join=bevel] coordinates {(0, 0.0) (0, 0.9) (3, 0.9) (4, 1) (5, 0.9) (80, 0)};
                \addplot +[miter limit=5] coordinates {(0, 0.0) (0, 0.9) (4, 0.9) (5, 1) (6, 0.9) (80, 0)};
            \end{axis}
        \end{tikzpicture}%
    }},draw,circle,minimum size=0.5cm] at (spypoint) {};
\end{tikzpicture}
\end{document}

Output