access a coordinate in a nested \tikzpicture

Question

In the following code

\documentclass{article}
\thispagestyle{empty}
\usepackage{graphicx}
\usepackage{tikz}
\begin{document}
\begin{figure}
  \begin{tikzpicture}
    \node(inset) {
      \begin{tikzpicture}
        \coordinate(v) at (3, 4);
        \node(t) at (v){v};
        \draw[->] (1,2) -- (v);
        \end{tikzpicture}
    };
    \node(t2)[blue] at (v){v};
    \draw[->, red](5, -2) -- (v);
  \end{tikzpicture}
\end{figure}
\end{document}

I try to draw an arrow to a specific point corresponding to \coordinate "v" in a nested \tikzpicture.

From the result it appears that \coordinate "v" has walked.

How to fix?

I do not know if there is a solution to your problem! - but do you know that nested tikzpictures are discouraged and are not guaranteed to work? — hpekristiansen, Jul 03 '17 at 16:40
it is because I need to access east and center coordinates of the nested picture - to put elegant labels pointing to contents of the nested picture. As far as I know these coordinates are accessible only from outside (after the nested picture has been finished). — Viesturs, Jul 03 '17 at 16:47
I think you're doing that the wrong way though, see if my answer is useful. — Torbjørn T., Jul 03 '17 at 16:52

score 7 · Accepted Answer · answered Jul 03 '17 at 16:52

Instead of nesting tikzpictures, use a local bounding box.

\documentclass{article}
\thispagestyle{empty}
\usepackage{tikz}
\usetikzlibrary{fit}
\begin{document}
\begin{figure}
\begin{tikzpicture}
\begin{scope}[local bounding box=inset]
        \coordinate(v) at (3, 4);
        \node(t) at (v){v};
        \draw[->] (1,2) -- (v);
\end{scope}
  \node(t2)[blue] at (v){v};
  \draw[->, red](5, -2) -- (v);

\draw [red] (inset.east) -- (inset.west);
\end{tikzpicture}
\end{figure}
\end{document}

Using a scope is an acceptable (better) alternative to a nested \tikzpicture. — Viesturs, Jul 03 '17 at 17:14

score 3 · Answer 2 · answered Jul 03 '17 at 16:55

You can use saveboxes to safely nest tikzpictures, and the coordinates will be remembered. The way [remember picture] works is to save the origin location in the aux file, so you have to run the code twice.

It should be noted that by placing the picture inside a node you are centering it (default) at the node location (origin).

\documentclass{article}
\thispagestyle{empty}
\usepackage{graphicx}
\usepackage{tikz}
\begin{document}
\begin{figure}
\sbox0{\begin{tikzpicture}[remember picture]
        \coordinate(v) at (3, 4);
        \node(t) at (v){v};
        \draw[->] (1,2) -- (v);
        \end{tikzpicture}
}
  \begin{tikzpicture}[remember picture]
    \node(inset) {\usebox0};
    \node(t2)[blue] at (v){v};
    \draw[->, red](5, -2) -- (v);
  \end{tikzpicture}
\end{figure}
\end{document}

fatts · Answer 3 · 2017-07-03T16:38:08.583

1

Try \tikzstyle{every picture}+=[remember picture]

\documentclass{article}
\thispagestyle{empty}
\usepackage{tikz}

\begin{document}
  \tikzstyle{every picture}+=[remember picture]
  \begin{tikzpicture}
    \node(inset) {
      \begin{tikzpicture}[remember picture]
       \coordinate(v) at (3, 4);
       \node(t) at (v){v};
       \draw[->] (1,2) -- (v);
      \end{tikzpicture}
    };
    \node(t2)[blue] at (v){v};
    \draw[->, red](5, -2) -- (v);
  \end{tikzpicture}
\end{document}

edited Jul 03 '17 at 16:38

answered Jul 03 '17 at 16:33

fatts

157

this solution worked – Viesturs Jul 03 '17 at 16:43
This is most unwise. Nesting tikzpictures is not supported. Period. If it happens to work, that's coincidence and it is liable to break any time. – cfr Jul 03 '17 at 23:29

access a coordinate in a nested \tikzpicture

3 Answers3

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