Connect coordinates in tikzpictures

Question

I use a "parent" tikzpicture to realize a more flexible positioning of pgfplots than what is possible with groupplots i.e. I put the pgfplots in nodes as in the following MWE:

\documentclass{article}

\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usetikzlibrary{positioning,calc}
\pgfplotsset{every axis/.append style={width=5cm}}

%\tikzstyle{every picture}+=[remember picture,overlay]

\begin{document}
\begin{tikzpicture}
\node (TL) {% Plot 1
    \begin{tikzpicture}
    \begin{axis}
    \addplot coordinates { (-5,100) (115,10) };
    \coordinate (C) at (axis cs: 0,0);
    \end{axis}
    \end{tikzpicture}
};
\node[right=1cm of TL] (TR) {% Plot 2
    \begin{tikzpicture}
    \begin{axis}
    \addplot coordinates { (-5,-120) (15,100) };
    \coordinate (D) at (axis cs: 0,0);
    \end{axis}
    \end{tikzpicture}
};
\node[anchor=north] (B) at ($(TL.south)!0.5!(TR.south)$) {% Plot 3
    \begin{tikzpicture}
    \begin{axis}
    \addplot coordinates { (-5,100) (115,100) };
    \end{axis}
    \end{tikzpicture}
};
\end{tikzpicture}
\end{document}

Is there a way to connect the coordinates (C) and (D) with a line? I tried the remember picture, overlay option, but this did not work and the position of the figure was on the top left corner of the page.

Answer 1

If you add the remember picture option you can then access these nodes in a different tikzpicture environment:

Notes:

• This is just to show how to use remember picture option and then connect the nodes. I am not recommending nesting tikzpicture environments.

Code:

\documentclass{article}

\usepackage{pgfplots}
\pgfplotsset{compat=newest}
\usetikzlibrary{positioning,calc}
\pgfplotsset{every axis/.append style={width=5cm}}

%\tikzstyle{every picture}+=[remember picture,overlay]

\begin{document}
\begin{tikzpicture}[remember picture]
\node (TL) {% Plot 1
    \begin{tikzpicture}
    \begin{axis}
    \addplot coordinates { (-5,100) (115,10) };
    \coordinate (C) at (axis cs: 0,0);
    \end{axis}
    \end{tikzpicture}
};
\node[right=1cm of TL] (TR) {% Plot 2
    \begin{tikzpicture}[remember picture]
    \begin{axis}
    \addplot coordinates { (-5,-120) (15,100) };
    \coordinate (D) at (axis cs: 0,0);
    \end{axis}
    \end{tikzpicture}
};
\node[anchor=north] (B) at ($(TL.south)!0.5!(TR.south)$) {% Plot 3
    \begin{tikzpicture}
    \begin{axis}
    \addplot coordinates { (-5,100) (115,100) };
    \end{axis}
    \end{tikzpicture}
};
\end{tikzpicture}
%
\begin{tikzpicture}[remember picture,overlay]
\draw [thick, red] (C) -- (D);
\end{tikzpicture}%
\end{document}