# LaTeX, qtree: Color and Animation for branches of a graph tree

I'm trying to do a beamer animation of a parse of a simple binary branching tree. I'd like to either use different colored branches and node labels to code the different steps of the parser and/or animate the parse. I don't know how to use \pause in the middle of a tree. Is that possible?

If I try to just do separate frames for each stage of the tree, LaTeX automatically resizes everything, so one node takes up a huge space on slide one, but less on slide two when it's joined with its daughters ... so it looks weird. Not like a structure that's being built one step at a time.

Any suggestions would be much appreciated!

{\Tree [.1 [.2 a ] [.3 [.4 b ] [.5 c ] ] ]}

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## migrated from stackoverflow.comMar 13 '12 at 7:11

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Welcome to TeX.sx! Your question was migrated here from Stack Overflow. Please register on this site, too, and make sure that both accounts are associated with each other, otherwise you won't be able to comment on or accept answers or edit your question. –  Werner Mar 13 '12 at 7:45
This is very difficult to do; and it may not be possible at all with tikz-qtree. See Beamer & TikZ: gradually unveil trees which is related, although not an exact duplicate, since it doesn't refer to qtree. –  Alan Munn Mar 13 '12 at 13:53
You might be able to apply the same technique as in the question I linked to in tikz-qtree. See How to specify left and right node of a tikz-qtree and How do I make an unbalanced binary tree for tips on how to add styles to particular edges or nodes in a tikz-qtree. –  Alan Munn Mar 13 '12 at 14:03

For a simple animation that, e.g. presents distinct levels of the tree one at a time, you can just use \only<> and successively larger trees. If you use the [t] alignment option on the frame, you don't get the spacing problem you refer to.

\documentclass{beamer}
\usepackage{tikz}
\usepackage{tikz-qtree}
\tikzset{edge from parent/.style={draw,very thick}}
\begin{document}
\begin{frame}[t]
\frametitle{A tree}
\begin{tikzpicture}
\only<1>{\Tree [.A B C ]}
\only<2>{\Tree [.A [.B D E ] [.C ]]}
\only<3>{\Tree [.A [.B D E ] [.C F G ]]}
\only<4>{\Tree [.A [.B \edge[red]; \node{D}; \edge[blue]; \node{E}; ] [.C [.F H I ] G ]]}
\end{tikzpicture}
\end{frame}

\end{document}


Colouring branches is fairly easy (I've given one example in the last version of the tree); using the same technique to animate everything isn't very easy, however.

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\documentclass{beamer}
\usepackage{qtree}
\begin{document}
\begin{frame}[t]{A tree}

\Tree [.1 [ .2 \pause a ] [.3 [.4 \pause b ] [.5 \pause c ] ] ]

\end{frame}
\end{document}

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