[Tex/LaTex] How to fix spacing on paths for a nested tikz flowchart

tikz-pgf

I'm trying to create a nested chart in tikz. I have a nonnested chart completed, but I'm trying to nest the blue boxes inside the first yellow box. I'm trying to follow the advice given here, so I created a tikz picture inside of the tikz picture. MWE below.
enter image description here
However, that throws off all of my node spacing (the paths inside the nested picture don't line up anymore, for some reason), and also makes the decisiong box have rounded corners…which is minor but perhaps related? Additionally, I have math formulas off to the side, which depend on the nodes in the blue boxes. I think it looks like they'll still compile with the nested tikz pictures, but the top two math formulas are now overlapping.

So, I have a few questions. Is this the best way to nest a flow chart? Can I have `outside nodes' that refer to nodes defined in a nested tikz picture? How do I fix the spacing on the node paths?

EDIT: It has been pointed out that nesting tikz pictures is not a good practice. Multiple solutions below modify tikz elements such that the figure appears nested, without actually nesting the tikzpicture enviroments.

MWE with both charts:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes, arrows, positioning}
\begin{document}

% Define block styles
\tikzstyle{decision} = [diamond, draw, fill=yellow!40, 
    text width=4.5em, text badly centered, node distance=1.75cm, inner sep=0pt]
\tikzstyle{decisiong} = [diamond, draw, fill=blue!40, 
    text width=4.5em, text badly centered, node distance=1.75cm, inner sep=0pt]
\tikzstyle{block} = [rectangle, node distance=1.75cm, minimum width=1cm, minimum height=0.5cm, draw, fill=yellow!20, 
    text width=20em, text centered, rounded corners, minimum height=1.5em]
\tikzstyle{blockg} = [rectangle, minimum width=1cm, minimum height=0.5cm, draw, fill=blue!20, 
    text width=15em, text centered, rounded corners, minimum height=1.5em]
\tikzstyle{line} = [draw, -latex']
\tikzstyle{cloud} = [draw, ellipse,fill=yellow!20, node distance=1.5cm, 
    minimum height=2em]
\tikzstyle{invis} = [draw, fill=yellow!10, node distance=4.25cm, 
    minimum height=2em]
\tikzstyle{invisg} = [draw, fill=yellow!10, node distance=3.5cm, 
    minimum height=2em]
\tikzstyle{matheq} = [node distance=8.75cm, text width=21em, minimum width=1cm, 
    minimum height=2em, text centered]


\begin{tikzpicture}[node distance = 1.25cm, auto]
    % Place nodes
    \node [cloud] (init) {update time};
    \node [matheq, right of=init] {$math$};

    \node [block, below of=init] (second) {iterate through all elements};
    \node [blockg, below of=second] (third) {local update};
    \node [matheq, right of=third] {$math$};
    \node [blockg, below of=third] (fourth) {calculate,\\ update };
    \node [matheq, right of=fourth] {$math$};
    \node [blockg, below of=fourth] (fifth) {calculate stuff};   
    \node [matheq, right of=fifth] {$math$};
    \node [decisiong, below of=fifth] (conver1) {{\scriptsize converged?}};
    % Draw edges
    \path [line] (init) -- (second);
    \path [line] (second) -- (third);
    \path [line] (third) -- (fourth);
    \path [line] (fourth) -- (fifth);
    \path [line] (fifth) -- (conver1); 
    \coordinate[left of=third] (c1);  %This is so the path doesn't intersect the diagram
    \coordinate[left of=conver1] (d1);
    \path [line] (conver1) -| node [near start] {no} ([xshift=-2.5cm]d1) -- ([xshift=-2.5cm]c1)-- (third);

    \node [block, below of=conver1] (solve) {solve global equations};
    \node [matheq, right of=solve] {$math$
    \\ $math$ \\ $math$}; 
    \node [decision, below of=solve] (conver) {{\scriptsize converged?}};
    \coordinate[right of=init] (a1);  %This is so the path doesn't intersect the diagram
    \coordinate[left of=conver] (b1);  
    \coordinate[right of=conver] (e1);
    \coordinate[left of=second] (f1);
    % Draw edges
    \path [line] (conver1) --node {yes} (solve);
    \path [line] (solve) -- (conver);
    \path [line] (conver) -| node [near start] {no} ([xshift=-3.25cm]b1) -- ([xshift=-3.25cm]f1)-- (second);


    \path [line] (conver) -| node [near start] {yes} ([xshift=3.25cm]e1) -- ([xshift=3.25cm]a1)-- (init);
\end{tikzpicture}


\clearpage
This should be the same chart, but the blue boxes should be nested inside the first yellow box.

\begin{tikzpicture}[node distance = 1.25cm, auto]
    % Place nodes
    \node [cloud] (init) {update time};
    \node [matheq, right of=init] {$math$};

    \node [block, below of=init] (second) {iterate through all elements
        \begin{tikzpicture}[node distance = 1.25cm, auto]
        \node [blockg] (third) {local update};
        \node [blockg, below of=third] (fourth) {calculate,\\ update};
        \node [blockg, below of=fourth] (fifth) {calculate stuff};   
        \node [decisiong, below of=fifth] (conver1) {{\scriptsize converged?}};
        \path [line] (third) -- (fourth);
        \path [line] (fourth) -- (fifth);
        \path [line] (fifth) -- (conver1);
        \end{tikzpicture}
        };
    %Math equations
    \node [matheq, right of=third] {$math$};
    \node [matheq, right of=fourth] {$math$};
    \node [matheq, right of=fifth] {$math$};
    % Draw edges
    \path [line] (init) -- (second);
    %\path [line] (second) -- (third);

    \coordinate[left of=third] (c1);
    \coordinate[left of=conver1] (d1);
    \path [line] (conver1) -| node [near start] {no} ([xshift=-2.5cm]d1) -- ([xshift=-2.5cm]c1)-- (third);

    \node [block, below of=conver1] (solve) {solve global equations};
    \node [matheq, right of=solve] {$math$
    \\ $math$ \\ $math$}; 
    \node [decision, below of=solve] (conver) {{\scriptsize converged?}};
    \coordinate[right of=init] (a1);
    \coordinate[left of=conver] (b1);  
    \coordinate[right of=conver] (e1);
    \coordinate[left of=second] (f1);
    % Draw edges
    \path [line] (conver1) --node {yes} (solve);
    \path [line] (solve) -- (conver);
    \path [line] (conver) -| node [near start] {no} ([xshift=-3.25cm]b1) -- ([xshift=-3.25cm]f1)-- (second);


    \path [line] (conver) -| node [near start] {yes} ([xshift=3.25cm]e1) -- ([xshift=3.25cm]a1)-- (init);
\end{tikzpicture}

\end{document}

Best Answer

Following you'll find an example with a background fitting node instead of a nesting tikzpicture. Is this what you want?

enter image description here

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shapes, arrows, positioning, fit, backgrounds}
\begin{document}

% Define block styles
\tikzstyle{decision} = [diamond, draw, fill=yellow!40, 
    text width=4.5em, text badly centered, node distance=1.75cm, inner sep=0pt]
\tikzstyle{decisiong} = [diamond, draw, fill=blue!40, 
    text width=4.5em, text badly centered, node distance=1.75cm, inner sep=0pt]
\tikzstyle{block} = [rectangle, node distance=1.75cm, minimum width=1cm, minimum height=0.5cm, draw, fill=yellow!20, 
    text width=20em, text centered, rounded corners, minimum height=1.5em]
\tikzstyle{blockg} = [rectangle, minimum width=1cm, minimum height=0.5cm, draw, fill=blue!20, 
    text width=15em, text centered, rounded corners, minimum height=1.5em]
\tikzstyle{line} = [draw, -latex']
\tikzstyle{cloud} = [draw, ellipse,fill=yellow!20, node distance=1.5cm, 
    minimum height=2em]
\tikzstyle{invis} = [draw, fill=yellow!10, node distance=4.25cm, 
    minimum height=2em]
\tikzstyle{invisg} = [draw, fill=yellow!10, node distance=3.5cm, 
    minimum height=2em]
\tikzstyle{matheq} = [node distance=8.75cm, text width=21em, minimum width=1cm, 
    minimum height=2em, text centered]


\begin{tikzpicture}[node distance = 1.25cm, auto]
    % Place nodes
    \node [cloud] (init) {update time};
    \node [matheq, right of=init] {$math$};

    \node [block, below of=init] (second) {iterate through all elements};
    \node [blockg, below of=second] (third) {local update};
    \node [matheq, right of=third] {$math$};
    \node [blockg, below of=third] (fourth) {calculate,\\ update };
    \node [matheq, right of=fourth] {$math$};
    \node [blockg, below of=fourth] (fifth) {calculate stuff};   
    \node [matheq, right of=fifth] {$math$};
    \node [decisiong, below of=fifth] (conver1) {{\scriptsize converged?}};

    \begin{scope}[on background layer]
    \node[draw, fill=yellow, fit=(second) (conver1), inner xsep=5mm]{};
    \end{scope}
    % Draw edges
    \path [line] (init) -- (second);
    \path [line] (second) -- (third);
    \path [line] (third) -- (fourth);
    \path [line] (fourth) -- (fifth);
    \path [line] (fifth) -- (conver1); 
    \coordinate[left of=third] (c1);  %This is so the path doesn't intersect the diagram
    \coordinate[left of=conver1] (d1);
    \path [line] (conver1) -| node [near start] {no} ([xshift=-2.5cm]d1) -- ([xshift=-2.5cm]c1)-- (third);

    \node [block, below of=conver1] (solve) {solve global equations};
    \node [matheq, right of=solve] {$math$
    \\ $math$ \\ $math$}; 
    \node [decision, below of=solve] (conver) {{\scriptsize converged?}};
    \coordinate[right of=init] (a1);  %This is so the path doesn't intersect the diagram
    \coordinate[left of=conver] (b1);  
    \coordinate[right of=conver] (e1);
    \coordinate[left of=second] (f1);
    % Draw edges
    \path [line] (conver1) --node {yes} (solve);
    \path [line] (solve) -- (conver);
    \path [line] (conver) -| node [near start] {no} ([xshift=-3.25cm]b1) -- ([xshift=-3.25cm]f1)-- (second);


    \path [line] (conver) -| node [near start] {yes} ([xshift=3.25cm]e1) -- ([xshift=3.25cm]a1)-- (init);
\end{tikzpicture}

\end{document}

Related Solutions

[Tex/LaTex] How to define the default vertical distance between nodes

I don't really get the question so I hope this is what you wanted. If you include a full document (such that we copy paste and see the problem on our systems) things are much more easier.

Here, you can change the default setting within a scope but your block style had a node distance which was resetting every time it is issued. I've made it 2mm such that we can see the difference easier.

\documentclass[tikz]{standalone}
\usetikzlibrary{arrows,shapes.geometric,positioning}

\begin{document}
\begin{tikzpicture}[decision/.style={diamond, draw, text width=4.5em, text badly centered, node distance=3.5cm, inner sep=0pt},
                    block/.style   ={rectangle, draw, text width=6em, text centered, rounded corners, minimum height=4em, minimum height=2em},
                    cloud/.style   ={draw, ellipse, minimum height=2em},
                    line/.style    ={draw,-latex'},
                    node distance = 1cm, 
                    auto]
    \node [block] (1st) {1st};
    \node [block, right= of 1st]  (2nd1) {2nd1};
\begin{scope}[node distance=2mm and 10mm]%Here we change it for everything inside this scope
    \node [block, above= of 2nd1] (2nd2) {2nd2};
    \node [block, below= of 2nd1] (2nd3) {2nd3};
    \node [block, right= of 2nd1] (3rd1) {3rd1};
    \node [block, above= of 3rd1] (3rd2) {3rd2};
    \node [block, above= of 3rd2] (3rd3) {3rd3};
\end{scope}
    \node [block, below= of 3rd1] (3rd4) {3rd4};
    \node [block, below= of 3rd4] (3rd5) {3rd5};

    \path [line] (1st) -- (2nd1);
    \path [line] (2nd1) -- (2nd2);
    \path [line] (2nd1) -- (2nd3);
    \path [line] (2nd2) -- (3rd3);
    \path [line] (2nd1) -- (3rd1);
    \path [line] (1st) -- (2nd1);
\end{tikzpicture}
\end{document}

enter image description here

[Tex/LaTex] TikZ: Drawing an arc from an intersection to an intersection

A solution which allows to draw intersection segments of any two intersections is available as tikz library fillbetween.

This library works as general purpose tikz library, but it is shipped with pgfplots and you need to load pgfplots in order to make it work:

\documentclass{standalone}

\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{fillbetween}

\begin{document}

\begin{tikzpicture}

\draw [name path=red,red] (120:1.06) circle (1.9);
%\draw [name path=yellow,yellow] (0:1.06) circle (2.12);
\draw [name path=green,green!50!black] (0:0.77) circle (2.41);
\draw [name path=blue,blue] (0:0) circle (1.06);

% substitute this temp path by `\path` to make it invisible:
\draw[name path=temp1, intersection segments={of=red and blue,sequence=L1}];
\draw[red,-stealth,ultra thick, intersection segments={of=temp1 and green,sequence=L3}];

\end{tikzpicture}

\end{document}

enter image description here

The key intersection segments is described in all detail in the pgfplots reference manual section "5.6.6 Intersection Segment Recombination"; the key idea in this case is to

create a temporary path temp1 which is the first intersection segment of red and blue, more precisely, it is the first intersection segment in the Left argument in red and blue : red. This path is drawn as thin black path. Substitute its \draw statement by \path to make it invisible.
Compute the desired intersection segment by intersecting temp1 and green and use the correct intersection segment. By trial and error I figured that it is the third segment of path temp1 which is written as L3 (L = left argument in temp1 and green and 3 means third segment of that path).

The argument involves some trial and error because fillbetween is unaware of the fact that end and startpoint are connected -- and we as end users do not see start and end point.

Note that you can connect these path segments with other paths. If such an intersection segment should be the continuation of another path, use -- as before the first argument in sequence. This allows to fill paths segments:

\documentclass{standalone}

\usepackage{tikz}
\usepackage{pgfplots}
\usetikzlibrary{fillbetween}

\begin{document}

\begin{tikzpicture}

\draw [name path=red,red] (120:1.06) circle (1.9);
%\draw [name path=yellow,yellow] (0:1.06) circle (2.12);
\draw [name path=green,green!50!black] (0:0.77) circle (2.41);
\draw [name path=blue,blue] (0:0) circle (1.06);

% substitute this temp path by `\path` to make it invisible:
\draw[name path=temp1, intersection segments={of=red and blue,sequence=L1}];
\draw[red,fill=blue,-stealth,ultra thick, intersection segments={of=temp1 and green,sequence=L3}]  
    [intersection segments={of=temp1 and green, sequence={--R2}}]
;

\end{tikzpicture}

\end{document}

enter image description here

Best Answer

Related Solutions

[Tex/LaTex] How to define the default vertical distance between nodes

[Tex/LaTex] TikZ: Drawing an arc from an intersection to an intersection

Related Question