Sstrhsrtj

I've made a plot like the one below to show a distribution of values in the dependent variable versus the change of the independent variable.

documentclass[varwidth]{standalone}

usepackage{pgfplots}

usepackage{pgfplotstable}

usepgfplotslibrary{fillbetween}

usepackage{tikz}



pgfplotstableread{

x min q1 med q3 max

1 0 2 4 6 8

2 2 4 5 6 8

3 1 3 5 7 9

}data%



begin{document}

begin{tikzpicture}

  begin{axis}[title=Example,

    xlabel=x,

    ylabel=y,

    ]

    addplot[blue, dashed] table [x=x, y=min] {data};

    addplot[blue, dotted, name path global=q1] table [x=x, y=q1] {data};

    addplot[blue, solid] table [x=x, y=med] {data};

    addplot[blue, dotted, name path global=q3] table [x=x, y=q3] {data};

    addplot[blue, dashed] table [x=x, y=max] {data};

    addplot[blue, fill opacity=0.3] fill between[of=q1 and q3];

  end{axis}

end{tikzpicture}



end{document}

I'd like to have a legend like the following,

Is that possible? How?

Edit: adding my full solution

The solution below got most of what I was looking for, and with a few minor edits I was able to get it perfect. (Well, the image below isn't quite perfect--just realized I switched Q1 and Q3.)

I increased the size of the custom legend entry from 0.1cm to 0.4cm,

pgfplotsset{custom legend/.style={%

                /pgfplots/legend image code/.code={%

                        path[##1] (0cm,-.4cm) rectangle (0.6cm,0.4cm);

                        draw[dotted] (0cm,-0.4cm) -- (0.6cm,-0.4cm)

                         (0cm,0.4cm) -- (0.6cm,0.4cm);

                         draw[blue] (0cm,0cm) -- (0.6cm,0cm);

                }}}

And made the corresponding legend entry three lines,

begin{axis}[title=Example,

  xlabel=x,

  ylabel=y,

  legend style={cells={align=left}},

  ]

  addlegendimage{blue,dashed}

  addlegendentry[font=sffamily]{Maximum}

  addlegendimage{custom legend,draw=none,fill=blue,fill opacity=0.3}

  addlegendentry[xshift=-2mm,font=sffamily]{Q1 \ Median \ Q3}

  addlegendimage{blue,dashed}

  addlegendentry[xshift=-0.2mm,font=sffamily]{Minimum}

...

Here is a proposal. I looked uparea legend in pgfplots.code.tex and used it as a basis for custom legend, which comes already close to what you want, I think, and can be further customized. (I am pretty sure I have seen an answer using similar tricks but even after some long search I couldn't find it. I am definitely not claiming that I am the first one doing these tricks.) Anyway, the result of a quick customization (after a long search without hits) is

documentclass[varwidth]{standalone}

usepackage{pgfplots}

usepackage{pgfplotstable}

usepgfplotslibrary{fillbetween}

usepackage{tikz}



pgfplotstableread{

x min q1 med q3 max

1 0 2 4 6 8

2 2 4 5 6 8

3 1 3 5 7 9

}data%

pgfplotsset{custom legend/.style={%

                /pgfplots/legend image code/.code={%

                        path[##1] (0cm,-0.1cm) rectangle (0.6cm,0.1cm);

                        draw[dotted] (0cm,-0.1cm) -- (0.6cm,-0.1cm)

                         (0cm,0.1cm) -- (0.6cm,0.1cm);

                         draw[blue] (0cm,0cm) -- (0.6cm,0cm);

                }}}

begin{document}

begin{tikzpicture}

  begin{axis}[title=Example,

    xlabel=x,

    ylabel=y,

    ]

    addlegendimage{blue,dashed}

    addlegendentry[font=sffamily]{Maximum}

    addlegendimage{custom legend,draw=none,fill=blue,fill opacity=0.3}

    addlegendentry[xshift=-2mm,font=sffamily]{Median}

    addlegendimage{blue,dashed}

    addlegendentry[xshift=-0.2mm,font=sffamily]{Minimum}

    addplot[blue, dashed] table [x=x, y=min] {data};

    addplot[blue, dotted, name path global=q1] table [x=x, y=q1] {data};

    addplot[blue, solid] table [x=x, y=med] {data};

    addplot[blue, dotted, name path global=q3] table [x=x, y=q3] {data};

    addplot[blue, dashed] table [x=x, y=max] {data};

    addplot[blue, fill opacity=0.3] fill between[of=q1 and q3];

  end{axis}

end{tikzpicture}

end{document}

After some amount of hibernation I will be happy to assist you in further customization, if needed.