tikz-algorithm-cbsm.tex

% SPDX-License-Identifier: CC-BY-4.0
% Copyright 2018 Toni Dietze
\documentclass[tikz]{standalone}
\usepackage{luatex85}% workaround problems with standalone
\usepackage{amsmath}
\usepackage[colon=literal, math-style=ISO]
           {unicode-math}
\usetikzlibrary{positioning}
\DeclareMathOperator{\mleOp}{mle}
\begin{document}
\begin{tikzpicture}
[ data/.style={align=center, draw, rounded corners}
, func/.style={align=center, draw}
, node distance = 1.2em and 3em
]

\node (merge) [func] {\strut find and apply best merger};

\node (c)     [data, above = of merge.north east, anchor = south east] {corpus};
\node (mle)   [func, above = of c] {\strut \(\mleOp\)};
\node (Mi)    [data, right = of mle] {\strut \(ℳ_i\)};

\node (Ai)    [data, anchor = west] at (merge.west |- mle) {\strut \(\mathcal{A}_i\)};

\draw[<-] (Ai) -- ++(-5em, 0) node[midway, above] {\(i ≔ 0\)};
\begin{scope}[->, line cap = rect, rounded corners]
	\draw (Ai)  -- (mle);
	\draw (Ai)  -| (merge);
	\draw (mle) -- (Mi);

	\draw (Ai |- merge.north) -- (Ai) node[midway, left] {\(i ≔ i + 1\)};

	\draw (c) to[bend left=20] (mle);
	\draw (c) to[bend left=20] (c |- merge.north);
\end{scope}
\end{tikzpicture}
\end{document}