TikZ-PGF – How to Draw a Flow Chart in TikZ

tikz-pgf

I have some old drawings prepared in Word which I would like to translate into TikZ. Being a complete novice and having never worked with TikZ before, I am really struggling with getting started.

Here is the first flow chart that I want to convert:

Flow chart to be converted from LaTeX to TikZ

One solution that appealed to me due to its simplicity was using a matrix and chains as explained in a tutorial in the manual. But then I already run into trouble with the two arrows that have to point to boxes 1, 2, and 3.

So my question boils down to: What is the easiest way to convert this chart into TikZ?
Don't worry I'm not asking for code. I just want to know how to start, because finding your way in something as complex as TikZ, with an 800 page manual!, can be very frustrating for a beginner.

Update Oct 17, 2011

Getting the hang of it! Here is the output I can currently produce. Last question:
Any ideas how to align the arrows by their tips?

\documentclass[ngerman]{scrartcl}

\usepackage{ucs}
\usepackage[utf8x]{inputenc}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,positioning,calc}

\begin{document}

\tikzstyle{block} = [rectangle, fill=blue!20, minimum height=3em, minimum width=6em] \tikzstyle{arrow} = [single arrow, draw]

\begin{tikzpicture}[auto, node distance=0.5cm and 0.5cm, arr/.style={->,thick}, line/.style={thick}, font=\footnotesize]

\node (stoffVor) [block] {Box 1 text};
\node (haupt) [block, right=of stoffVor, align=center] {Box 2 text};
\node (stoffNach) [block, right=of haupt] {Box 3 text};
\node (pfeil1) [arrow, below left=of stoffVor] {Arrow 1};
\node (pfeil2) [arrow, below=of pfeil1] {Arrow 2 text};
\node (pfeil0) [arrow, left=of stoffVor] {Arrow 3 longer text};
\node (neben) [arrow, below right=of stoffNach, label=below:, yshift=0.5cm, xshift=1cm] {Text};
\node (hauptP) [arrow, above right=of stoffNach, label=above:,yshift=-0.5cm,xshift=1cm] {Text};
\node (pfeil3) [arrow, above=of hauptP] {Text};
\node (pfeil4) [arrow, above=of pfeil3] {Lorem, Ipsum, Dolor, Sit};

\draw[arr] (pfeil0.east) -- (stoffVor.west);
\draw[arr] (stoffVor.east) -- (haupt.west);
\draw[arr] (haupt.east) -- (stoffNach.west);
\draw[arr] (stoffNach.north) --  ++(0,0.5) node [auto, swap, yshift=6] {Text} -| ($ (stoffVor.east) + (0.25,0) $);
\draw[arr] (pfeil1.east) -| (stoffVor.240);
\draw[arr] (pfeil1.east) -| (haupt.240);
\draw[arr] (pfeil1.east) -| (stoffNach.240);
\draw[arr] (pfeil2.east) -| (stoffVor.300);
\draw[arr] (pfeil2.east) -| (haupt.300);
\draw[arr] (pfeil2.east) -| (stoffNach.300);
\draw[line] (haupt.150) |-  (pfeil4.west);
\draw[line] (haupt.30) |-  (pfeil3.west);
\draw[line] (stoffNach.350) -- ++ (0.25,0) -- ++ (0,-0.1) |- (neben.west);
\draw[line] (stoffNach.10) -- ++ (0.25,0) -- ++ (0, +0.1) |- (hauptP.west);

\end{tikzpicture}

\end{document}

enter image description here

Best Answer

The boxes could be nodes, something like

\node (box1) at (0,2) [rectangle,draw=black,fill=blue!20!white] {Box 1};

Notice the (box1), thats the name of that node, you can use it for easily drawing arrows:

\draw[->] (box1.east) -- (box2.west);

For the arrows with kinks, you can use the ++(x,y) coordinate notation, which means 'from the last position, go x right and y up, then make this the new position':

\draw[->] (box1.north) -- ++(0,1) -- ++(4,0) -- (box2.north);

Hope this helps getting started :)

Edit 1: You really learn TikZ by doing. I was wondering how to draw the double arrows entering the boxes on the south side. You could use the fact that you can specify any angle at which the arrows leave/enter:

\draw[->] (box1.300) -- ++(0,-0.5) -- ++(4,0) -- (box2.240);
\draw[->] (box1.240) -- ++(0,-1.0) -- ++(4,0) -- (box2.300);

However, the distance between entry and exit point is no longer 4. So it would be nice to specify 1cm below box2.240 which you can do with the calc library:

\coordinate (A) at ($ (box2.240) + (0,-0.5) $);
\coordinate (B) at ($ (box2.300) + (0,-1.0) $);
\draw[->] (box1.300) -- ++(0,-0.5) -- (A) -- (box2.240);
\draw[->] (box1.240) -- ++(0,-1.0) -- (B) -- (box2.300);

This should cover most things needed for your chart. Here a little example and a picture:

\documentclass[parskip]{scrartcl}
\usepackage[margin=15mm]{geometry}
\usepackage{tikz}
\usetikzlibrary{calc}

\begin{document}

\begin{tikzpicture}
\node (box1) at (0,0) [rectangle,draw=black,fill=blue!20!white] {Box 1};
\node (box2) at  (4,0) [rectangle,draw=black,fill=blue!20!white] {Box 2};
\draw[->] (box1.east) -- (box2.west);
\draw[->] (box1.north) -- ++(0,1) -- ++(4,0) -- (box2.north);
\coordinate (A) at ($ (box2.240) + (0,-0.5) $);
\coordinate (B) at ($ (box2.300) + (0,-1.0) $);
\draw[->] (box1.300) -- ++(0,-0.5) -- (A) -- (box2.240);
\draw[->] (box1.240) -- ++(0,-1.0) -- (B) -- (box2.300);
\end{tikzpicture}

\end{document}

enter image description here

Edit 2: A nice, calc free version by percusse:

\begin{tikzpicture}
 \node (box1) at (0,0) [draw,fill=blue!20!white] {Box 1};
 \node (box2) at (4,0) [draw,fill=blue!20!white] {Box 2};
 \draw[->] (box1) -- (box2);
 \draw[->] (box1.north) -- ++(0,1) -| (box2.north);
 \draw[->] (box1.300) -- ++(0,-0.5) -| (box2.240);
 \draw[->] (box1.240) -- ++(0,-1.0) -| (box2.300);
\end{tikzpicture}

Edit 3: Regarding the request for tip aligned arrows: I could not (right now) think of anything elegent, so I used absolute coordinates and the left option, e.g. draw the node left of the coordinates, e.g. ending at the specified coordinates:

\documentclass[ngerman]{scrartcl}

\usepackage{ucs}
\usepackage[utf8x]{inputenc}
\usepackage{tikz}
\usetikzlibrary{shapes,arrows,positioning,calc}

\begin{document}

\tikzstyle{block} = [rectangle, fill=blue!20, minimum height=3em, minimum width=6em] \tikzstyle{arrow} = [single arrow, draw]

\begin{tikzpicture}[auto, node distance=0.5cm and 0.5cm, arr/.style={->,thick}, line/.style={thick}, font=\footnotesize]

\node (stoffVor) [block] {Box 1 text};
\node (haupt) [block, right=of stoffVor, align=center] {Box 2 text};
\node (stoffNach) [block, right=of haupt] {Box 3 text};
\node (pfeil1) at (-2,-1.5) [arrow,left] {Arrow 1};
\node (pfeil2) at (-2,-2.5) [arrow,left] {Arrow 2 text};
\node (pfeil0) at (-2,0) [arrow,left] {Arrow 3 longer text};
\node (neben) at (9.5,-0.5) [arrow,left,label=below:] {Text};
\node (hauptP) at (9.5,0.5) [arrow,left,label=above:] {Text};
\node (pfeil3) at (9.5,1.5) [arrow,left] {Text};
\node (pfeil4) at (9.5,2.5) [arrow,left] {Lorem, Ipsum, Dolor, Sit};

\draw[arr] (pfeil0.east) -- (stoffVor.west);
\draw[arr] (stoffVor.east) -- (haupt.west);
\draw[arr] (haupt.east) -- (stoffNach.west);
\draw[arr] (stoffNach.north) --  ++(0,0.5) node [auto, swap, yshift=6] {Text} -| ($ (stoffVor.east) + (0.25,0) $);
\draw[arr] (pfeil1.east) -| (stoffVor.240);
\draw[arr] (pfeil1.east) -| (haupt.240);
\draw[arr] (pfeil1.east) -| (stoffNach.240);
\draw[arr] (pfeil2.east) -| (stoffVor.300);
\draw[arr] (pfeil2.east) -| (haupt.300);
\draw[arr] (pfeil2.east) -| (stoffNach.300);
\draw[line] (haupt.150) |-  (pfeil4.west);
\draw[line] (haupt.30) |-  (pfeil3.west);
\draw[line] (stoffNach.350) -- ++ (0.25,0) -- ++ (0,-0.1) |- (neben.west);
\draw[line] (stoffNach.10) -- ++ (0.25,0) -- ++ (0, +0.1) |- (hauptP.west);

\end{tikzpicture}

\end{document}

enter image description here

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] Drawing flow diagram in LaTeX using TikZ

You can use positioning library and a useful reading will be this question. Further, tikzstyle is deprecated, use tikzset instead.

\documentclass[border=10pt]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows,positioning,shapes.geometric}
\begin{document}
    \begin{tikzpicture}[>=latex']
        \tikzset{block/.style= {draw, rectangle, align=center,minimum width=2cm,minimum height=1cm},
        rblock/.style={draw, shape=rectangle,rounded corners=1.5em,align=center,minimum width=2cm,minimum height=1cm},
        input/.style={ % requires library shapes.geometric
        draw,
        trapezium,
        trapezium left angle=60,
        trapezium right angle=120,
        minimum width=2cm,
        align=center,
        minimum height=1cm
    },
        }
        \node [rblock]  (start) {Start};
        \node [block, right =2cm of start] (acquire) {Acquire Image};
        \node [block, right =2cm of acquire] (rgb2gray) {RGB to Gray};
        \node [block, right =2cm of rgb2gray] (otsu) {Localized OTSU \\ Thresholding};
        \node [block, below right =2cm and -0.5cm of start] (gchannel) {Subtract the \\ Green Channel};
        \node [block, right =2cm of gchannel] (closing) {Morphological \\ Closing};
        \node [block, right =2cm of closing] (NN) {Sign Detection \\ Using NN};
        \node [input, right =2cm of NN] (limit) {Speed \\ Limit};
        \node [coordinate, below right =1cm and 1cm of otsu] (right) {};  %% Coordinate on right and middle
        \node [coordinate,above left =1cm and 1cm of gchannel] (left) {};  %% Coordinate on left and middle

%% paths
        \path[draw,->] (start) edge (acquire)
                    (acquire) edge (rgb2gray)
                    (rgb2gray) edge (otsu)
                    (otsu.east) -| (right) -- (left) |- (gchannel)
                    (gchannel) edge (closing)
                    (closing) edge (NN)
                    (NN) edge (limit)
                    ;
    \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] Drawing flow diagram in LaTeX using TikZ

Related Question