4

Trying to make a tree where each child is a set of nodes that can be created separately and then linked somehow in to different positions in a tree.

Lets say I have a group of nodes and edges such as

\node (1) at (0,1) {1};
\node (2) at (0,2) {2};
\draw(->, bend left=90, dotted) (1.north) -- (2.north);

I have looked at trees and it seems that each child can only be one node. I would like to be able to use, for example, the three above commands and treat them as one child (and have the relative coordinates kept within a child). Perhaps it is possible to do this with a macro(?) although I can't find any examples/literature on it.

For example, something like the following:

\documentclass{article}
\usepackage{tikz}
\begin{document}

\begin{tikzpicture} 
  \node {root} 
    child {\node (1) at (0,0) {A}; \node (1) at (0,0) {B}};
    child {\node (1) at (0,0) {C}; \node (1) at (0,0) {D} 
      child {\node (1) at (0,0) {C};} 
      child {\node (1) at (0,0) {D};} 
    }; 
\end{tikzpicture}

\end{document}
dogAwakeCat
  • 271
  • Please post code that compiles, preferably as a minimal working example including \documentclass and loading the necessary packages. As it stands your final example does not produce a valid tree: for example node should be used instead of \node except at the root. – Andrew Swann Oct 09 '14 at 07:43
  • You can try with pics (pgfmanual, section 18) but I'm not sure about their use in trees. – Ignasi Oct 09 '14 at 07:59
  • @Andrew Swann I know it doesn't compile; I am suggesting that as an example of how I would like to have several nodes within one child. – dogAwakeCat Oct 09 '14 at 08:02
  • James, the point that Andrew Swann was making is that it is much better to post complete code that compiles so that people have something to work from. This saves a lot of time for everyone, and it makes it much more likely that people will try and help. –  Oct 09 '14 at 08:08
  • relevant? http://tex.stackexchange.com/questions/136855/how-to-draw-search-space-tree-in-a-dynamic-manner – seteropere Oct 09 '14 at 08:17
  • @Andrew I understand this. If I had code that compiled I would post it, but I also wouldn't be asking for help. – dogAwakeCat Oct 09 '14 at 08:26
  • @seteropere Thanks. I looked at the forest environment and it didn't look like it did what I wanted, although I may be wrong. – dogAwakeCat Oct 09 '14 at 08:28
  • Even if it is not good practice, you can put \tikz...; commands inside the contents of a node...is this what you want? A node in the tree can contain arbitrary tikz code? – Bordaigorl Oct 09 '14 at 13:45
  • @James Even if you cannot make it compile, you surely can make it closer to being compilable. For example, you presumably don't need help to know that it won't compile with \documentclass, relevant \usepackage and \begin{document} ... \end{document}. – cfr Oct 09 '14 at 21:19

1 Answers1

4

It is not entirely clear to me what you after, but you can certainly write subtrees as macros, which should start with a child. Alternatively you can use pics. I give three examples:

Sample output level

\documentclass{article}

\usepackage{tikz}

\begin{document}

\newcommand{\mysubtree}[2]{child {node {#1}} 
      child {node {#2}}}

\begin{tikzpicture}[level 2/.style={sibling distance=1cm}] 
  \node (R) {root} 
  child {node  {A}
  child {node  {B}}}
  child {node {C} \mysubtree DE}
  child {node {F} \mysubtree GH}; 
\end{tikzpicture}

\end{document}

You can add quite complicated code to these macros:

Sample coloured output

\documentclass{article}

\usepackage{tikz}

\begin{document}

\newcommand{\mysubtree}[3]{child {node[red] {#1}
      child {node[draw] {#2}} 
      child[edge from parent path={(\tikzparentnode\tikzparentanchor)
        edge [bend left] (\tikzchildnode\tikzchildanchor)}]
        {node[circle,fill=green] {#3} }}} 


\begin{tikzpicture} 
  \node {root} 
  child {node  {A}
   child {node  {B}
    \mysubtree CDE
    \mysubtree FGH}}; 
\end{tikzpicture}

\end{document}

Finally using pics may be closest to what you ask. You can simply place a pic instead of a node but there is an anchoring problem for the edges, see the right most node below. Instead place these together with a dummy node that takes is a blank rectangle of appropriate size:

Sample pic output

\documentclass{article}

\usepackage{tikz}
\tikzset{ mynode/.pic={
  \node (1) at (-0.25,0) {1};
  \node (2) at (0.25,0) {2};
  \draw[->, bend left=90, dotted] (1.north) -- (2.north);
  },
  mypic/.style={rectangle,minimum size=4ex}
}

\begin{document}

\begin{tikzpicture}
  \node (R) {root} 
  child {node  {A}
  child {node  {B}}}
  child { node[mypic] {} pic {mynode} }
  child { node[mypic] {} pic {mynode} }
  child { pic {mynode} }; 
\end{tikzpicture}

\end{document}
Andrew Swann
  • 95,762