Example: Data flow diagram

Published 2013-03-09 | Author: David Fokkema

Data flow diagrams depict the flow of information in a system. This figure shows experimental data being recorded, processed and ultimately stored. This figure is a minor revision of the one included in my PhD thesis.

Download as: [PDF] [TEX]  •  [Open in Overleaf]

Data flow diagram

Do you have a question regarding this example, TikZ or LaTeX in general? Just ask in the LaTeX Forum.
Oder frag auf Deutsch auf TeXwelt.de. En français: TeXnique.fr.

% Data flow diagram
% Author: David Fokkema
\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{arrows}

% Defines a `datastore' shape for use in DFDs.  This inherits from a
% rectangle and only draws two horizontal lines.
\makeatletter
\pgfdeclareshape{datastore}{
  \inheritsavedanchors[from=rectangle]
  \inheritanchorborder[from=rectangle]
  \inheritanchor[from=rectangle]{center}
  \inheritanchor[from=rectangle]{base}
  \inheritanchor[from=rectangle]{north}
  \inheritanchor[from=rectangle]{north east}
  \inheritanchor[from=rectangle]{east}
  \inheritanchor[from=rectangle]{south east}
  \inheritanchor[from=rectangle]{south}
  \inheritanchor[from=rectangle]{south west}
  \inheritanchor[from=rectangle]{west}
  \inheritanchor[from=rectangle]{north west}
  \backgroundpath{
    %  store lower right in xa/ya and upper right in xb/yb
    \southwest \pgf@xa=\pgf@x \pgf@ya=\pgf@y
    \northeast \pgf@xb=\pgf@x \pgf@yb=\pgf@y
    \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@ya}}
    \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@ya}}
    \pgfpathmoveto{\pgfpoint{\pgf@xa}{\pgf@yb}}
    \pgfpathlineto{\pgfpoint{\pgf@xb}{\pgf@yb}}
 }
}
\makeatother

\begin{document}
\begin{center}
\begin{tikzpicture}[
  font=\sffamily,
  every matrix/.style={ampersand replacement=\&,column sep=2cm,row sep=2cm},
  source/.style={draw,thick,rounded corners,fill=yellow!20,inner sep=.3cm},
  process/.style={draw,thick,circle,fill=blue!20},
  sink/.style={source,fill=green!20},
  datastore/.style={draw,very thick,shape=datastore,inner sep=.3cm},
  dots/.style={gray,scale=2},
  to/.style={->,>=stealth',shorten >=1pt,semithick,font=\sffamily\footnotesize},
  every node/.style={align=center}]

  % Position the nodes using a matrix layout
  \matrix{
    \node[source] (hisparcbox) {electronics};
      \& \node[process] (daq) {DAQ}; \& \\

    \& \node[datastore] (buffer) {buffer}; \& \\

    \node[datastore] (storage) {storage};
      \& \node[process] (monitor) {monitor};
      \& \node[sink] (datastore) {datastore}; \\
  };

  % Draw the arrows between the nodes and label them.
  \draw[to] (hisparcbox) -- node[midway,above] {raw events}
      node[midway,below] {level 0} (daq);
  \draw[to] (daq) -- node[midway,right] {raw event data\\level 1} (buffer);
  \draw[to] (buffer) --
      node[midway,right] {raw event data\\level 1} (monitor);
  \draw[to] (monitor) to[bend right=50] node[midway,above] {events}
      node[midway,below] {level 1} (storage);
  \draw[to] (storage) to[bend right=50] node[midway,above] {events}
      node[midway,below] {level 1} (monitor);
  \draw[to] (monitor) -- node[midway,above] {events}
      node[midway,below] {level 1} (datastore);
\end{tikzpicture}
\end{center}
\end{document}

Comments

  • #1 Qrrbrbirlbel, June 25, 2013 at 11:39 p.m.

    The background path is not correct. The outer xsep and the outer ysep must be included in the calculation of the lines’ path. This is most noticeable if one removes the shorten > option from the to style and/or adds a drawing color other than black.

Adding comments is currently not enabled.