# Drawing a circle around nodes in flow chart using Beamer

I am trying to draw a circle around a bunch of nodes in a flow chart that I've created using beamer and I can't figure out how to do it. Ideally, I'd like the circle to encompass most (but not all of the nodes). How do I do this?

Here is my code:

\begin{frame}
\frametitle{The Regime Complex for Climate Change\\(Keohane and Victor (2011) )}

\tikzstyle{type1} = [rectangle, rounded corners, minimum width=3cm, minimum height=0.1cm,text centered, draw=black, fill=blue!10, text width=2cm]

\tikzstyle{type2} = [rectangle, rounded corners, minimum width=3cm, minimum height=0.1cm, text centered, draw=black, fill=blue!10, text width=5cm]

\tikzstyle{info} = [rectangle, rounded corners, minimum width=2.5cm, minimum height=0.1cm, text centered, draw=black,
fill=blue!30, text width=2.5cm]
\tikzstyle{org} = [rectangle, rounded corners, minimum width=2cm, minimum height=0.1cm, text centered, draw=black,
fill=blue!30, text width=3cm]
\tikzstyle{decision} = [square, minimum width=1cm, minimum height=0.1cm, text centered,
draw=black, fill=green!30, text width=4cm]

\tikzstyle{arrow} = [thick,->,>=stealth]

\begin{tikzpicture}[node distance=1.2cm]

\node (un) [type1, xshift=-3cm] {UN Legal Regimes};
\node (expert) [type1, right of=un, xshift=4cm]{Expert Assessments};

\node (montreal)[type1, below of=un, xshift=-1cm]{Montreal Protocol};
\node (bilateral)[type1, right of=montreal, xshift=3cm]{Bilateral Initiatives};
\node (clubs)[type1, right of=bilateral, xshift=2cm]{Clubs};

\node(subnat)[type1, below of=montreal, xshift=1cm]{Subnational Action};
\node(MDA)[type1, right of=subnat, xshift=4cm]{MDA};

\node(geo)[type1, below of=subnat, xshift=-1cm]{Geoengineering Governance};
\node(nuc)[type1, right of=geo, xshift=2cm]{Nuclear Technology};
\node(fin)[type1, right of=nuc, xshift=2cm]{Financial Market Rules};

\node(intel)[type2, below of=geo, xshift=1cm]{Intel Property and Investment Rules};

\end{tikzpicture}

\end{frame}

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Hi, welcome to TeX.SX. If you select your code and click on the button marked {} it will be highlighted as you see above. (Edit: I also added a missing semicolon after the last node.) –  Torbjørn T. Nov 27 '13 at 19:47

This can be achieved using the fit library, using for example

    \node[draw=red,double,fit=(un) (montreal) ,inner sep=1ex,circle] (tmp) {};


Note that in the code below I have used tikzset instead of tikzstyle as described in Should \tikzset or \tikzstyle be used to define TikZ styles?

% arara: pdflatex
\documentclass{beamer}

\usepackage{tikz}
\usetikzlibrary{fit}

\tikzset{type1/.style={rectangle, rounded corners, minimum width=3cm, minimum height=0.1cm,text centered, draw=black, fill=blue!10, text width=2cm},
type2/.style={rectangle, rounded corners, minimum width=3cm, minimum height=0.1cm, text centered, draw=black, fill=blue!10, text width=5cm},
info/.style = {rectangle, rounded corners, minimum width=2.5cm, minimum height=0.1cm, text centered, draw=black,
fill=blue!30, text width=2.5cm},
org/.style={rectangle, rounded corners, minimum width=2cm, minimum height=0.1cm, text centered, draw=black,
fill=blue!30, text width=3cm},
decision/.style = {square, minimum width=1cm, minimum height=0.1cm, text centered,
draw=black, fill=green!30, text width=4cm},
arrow/.style = {thick,->,>=stealth},
}

\begin{document}

\begin{frame}
\frametitle{The Regime Complex for Climate Change\\(Keohane and Victor (2011) )}

\begin{tikzpicture}[node distance=1.2cm]

\node (un) [type1, xshift=-3cm] {UN Legal Regimes};
\node (expert) [type1, right of=un, xshift=4cm]{Expert Assessments};

\node (montreal)[type1, below of=un, xshift=-1cm]{Montreal Protocol};
\node (bilateral)[type1, right of=montreal, xshift=3cm]{Bilateral Initiatives};
\node (clubs)[type1, right of=bilateral, xshift=2cm]{Clubs};

\node(subnat)[type1, below of=montreal, xshift=1cm]{Subnational Action};
\node(MDA)[type1, right of=subnat, xshift=4cm]{MDA};

\node(geo)[type1, below of=subnat, xshift=-1cm]{Geoengineering Governance};
\node(nuc)[type1, right of=geo, xshift=2cm]{Nuclear Technology};
\node(fin)[type1, right of=nuc, xshift=2cm]{Financial Market Rules};

\node(intel)[type2, below of=geo, xshift=1cm]{Intel Property and Investment Rules};

\node[draw=red,double,fit=(un) (montreal) ,inner sep=1ex,circle] (tmp) {};

\end{tikzpicture}

\end{frame}
\end{document}

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You mean "tikzset instead of tikzstyle" right? :) –  Herr K. Nov 27 '13 at 20:09
Isn't the of= syntax deprecated or something, in favour of =of with the positioning library? There was a question about this, but I can't find it right now. –  Torbjørn T. Nov 27 '13 at 20:12
–  Torbjørn T. Nov 27 '13 at 20:13
@KevinC thanks- got the code right, but not the description :) –  cmhughes Nov 27 '13 at 20:18
@TorbjørnT. yes indeed, thanks for the link... it requires a fair bit of tweaking to update it- I'll leave that as something for the OP –  cmhughes Nov 27 '13 at 20:24