latex flow diagrams
documentclass{article}
usepackage[latin1]{inputenc}
usepackage{tikz}
usetikzlibrary{shapes,arrows}
begin{document}
pagestyle{empty}
% Define block styles
tikzstyle{decision} = [diamond, draw, fill=blue!20,
text width=4.5em, text badly centered, node distance=3cm, inner sep=0pt]
tikzstyle{block} = [rectangle, draw, fill=blue!20,
text width=5em, text centered, rounded corners, minimum height=4em]
tikzstyle{line} = [draw, -latex']
tikzstyle{cloud} = [draw, ellipse,fill=red!20, node distance=3cm,
minimum height=2em]
begin{tikzpicture}[node distance = 2cm, auto]
% Place nodes
node [block] (init) {initialize model};
node [cloud, left of=init] (expert) {expert};
node [cloud, right of=init] (system) {system};
node [block, below of=init] (identify) {identify candidate models};
node [block, below of=identify] (evaluate) {evaluate candidate models};
node [block, left of=evaluate, node distance=3cm] (update) {update model};
node [decision, below of=evaluate] (decide) {is best candidate better?};
node [block, below of=decide, node distance=3cm] (stop) {stop};
% Draw edges
path [line] (init) -- (identify);
path [line] (identify) -- (evaluate);
path [line] (evaluate) -- (decide);
path [line] (decide) -| node [near start] {yes} (update);
path [line] (update) |- (identify);
path [line] (decide) -- node {no}(stop);
path [line,dashed] (expert) -- (init);
path [line,dashed] (system) -- (init);
path [line,dashed] (system) |- (evaluate);
end{tikzpicture}
end{document}