[Tex/LaTex] Creating sub-algorithms in latex using the algorithm package

algorithmspackages

I want to do something like this (see image below)
where I can describe my algorithm in smaller steps or "phases" as this person calls them. I've used the algorithm and algorithmic package before but I can't figure out how to do these "sub-algorithms" and i cant seem to find it in any tutorial.
enter image description here

Best Answer

You can use the algpseudocode package and define a simple command to let you format the phases; a simple example:

\documentclass{article}
\usepackage{algorithm}
\usepackage{algpseudocode}

\newcommand\Algphase[1]{%
\vspace*{-.7\baselineskip}\Statex\hspace*{\dimexpr-\algorithmicindent-2pt\relax}\rule{\textwidth}{0.4pt}%
\Statex\hspace*{-\algorithmicindent}\textbf{#1}%
\vspace*{-.7\baselineskip}\Statex\hspace*{\dimexpr-\algorithmicindent-2pt\relax}\rule{\textwidth}{0.4pt}%
}
\begin{document}

\begin{algorithm}
\caption{Euclid’s algorithm}\label{euclid}
\begin{algorithmic}[1]
\Require something
\Ensure something
\Procedure{Euclid}{$a,b$}\Comment{The g.c.d. of a and b}
\State $r\gets a\bmod b$
\While{$r\not=0$}\Comment{We have the answer if r is 0}
\State $a\gets b$
\State $b\gets r$
\State $r\gets a\bmod b$
\EndWhile\label{euclidendwhile}
\State \textbf{return} $b$\Comment{The gcd is b}
\EndProcedure%
\Algphase{Phase 1 - Gossip piece ids}
\Require something
\Function{somename}{someparams}
\While{$x>-5$}
\State $x\gets x-1$
\EndWhile
\EndFunction
\Algphase{Phase 2 - Require chunks}
\Ensure something
\Procedure{somename}{someparams}
\While{$x>-5$}
\State $x\gets x-1$
\EndWhile
\EndProcedure
\end{algorithmic}
\end{algorithm}

\end{document}

enter image description here

Related Solutions

[Tex/LaTex] Recursive algorithms with the »algorithms« package

There doesn’t seem to be a way of defining procedures in algorithms but you can use an algorithm environment with an appropriate \caption that names your algorithm.

Personally, though, I would switch to the superior algorithmicx package that defines a \Procedure macro:

\begin{algorithm}
\Procedure{recurse}{$x$}
  \If{$x=1$}
    \State\Return{$1$}
  \Else
    \State\Return{\Call{recurse}{$x-1$}}
  \EndIf
\EndProcedure
\end{algorithm}

[Tex/LaTex] 3 Algorithms in the same column with algorithmic

The main problem here is using floats in a twocolumn document. Although it is possible, your needs do not conform to their purpose. Instead, the caption package removes the float-y-ness of floats, allowing you to specify a caption in the text where it is called.

The following MWE uses algorithmicx's algpseudocode to display an algorithm with slight variations across the three. The main interface for non-floating captions using caption is

\captionof{<float env>}{<caption>}

Since I loaded algorithm, <float env> can be algorithm to obtain the appropriate caption.

enter image description here

\documentclass[twocolumn]{article}
\usepackage[margin=1in]{geometry}% http://ctan.org/pkg/geometry
\usepackage{algorithm,algpseudocode,lipsum}% http://ctan.org/pkg/{algorithms,algorithmicx,lipsum}
\usepackage{caption}% http://ctan.org/pkg/caption
\begin{document}
\lipsum[87]
\captionof{algorithm}{Euclid’s algorithm A}\label{euclidA}
\begin{algorithmic}[1]
  \Procedure{Euclid}{$a,b$}\Comment{GCD of $a$ and $b$}
    \State $r_1\gets a\bmod b$
    \While{$r\not=0$}\Comment{$r=0\mapsto\mbox{answer}$}
    \State $a\gets b$
    \State $b\gets r$
    \State $r\gets a\bmod b$
    \EndWhile\label{euclidendwhile1}
  \State \textbf{return} $b$\Comment{The GCD is $b$}
  \EndProcedure
\end{algorithmic}

\captionof{algorithm}{Euclid’s algorithm B}\label{euclidB}
\begin{algorithmic}[1]
  \Procedure{Euclid}{$a,b$}\Comment{GCD of $a$ and $b$}
    \State $r_2\gets a\bmod b$
    \While{$r\not=0$}\Comment{$r=0\mapsto\mbox{answer}$}
    \State $a\gets b$
    \State $b\gets r$
    \State $r\gets a\bmod b$
    \EndWhile\label{euclidendwhile2}
  \State \textbf{return} $b$\Comment{The GCD is $b$}
  \EndProcedure
\end{algorithmic}

\captionof{algorithm}{Euclid’s algorithm C}\label{euclidC}
\begin{algorithmic}[1]
  \Procedure{Euclid}{$a,b$}\Comment{GCD of $a$ and $b$}
    \State $r_3\gets a\bmod b$
    \While{$r\not=0$}\Comment{$r=0\mapsto\mbox{answer}$}
    \State $a\gets b$
    \State $b\gets r$
    \State $r\gets a\bmod b$
    \EndWhile\label{euclidendwhile3}
  \State \textbf{return} $b$\Comment{The GCD is $b$}
  \EndProcedure
\end{algorithmic}

\lipsum[1-5]
\end{document}

geometry, lipsum were just used for layout and dummy text.

There's also the stand-alone capt-of package which does something similar, as well as ccaption.

Keeping things together in a float-like environment is possible. Wrap the set of algorithms in a figure (yes, a figure, or table) environment while still using \captionof{algorithm}, or just place them all in an algorithm environment with a \caption for each. The following shows the former:

enter image description here

\documentclass[twocolumn]{article}
\usepackage[margin=1in]{geometry}% http://ctan.org/pkg/geometry
\usepackage{algorithm,algpseudocode,lipsum}% http://ctan.org/pkg/{algorithms,algorithmicx,lipsum}
\usepackage{caption}% http://ctan.org/pkg/caption
\begin{document}
\lipsum[1-2]
\begin{figure}[t]
\captionof{algorithm}{Euclid’s algorithm A}\label{euclidA}
\begin{algorithmic}[1]
  \Procedure{Euclid}{$a,b$}\Comment{GCD of $a$ and $b$}
    \State $r_1\gets a\bmod b$
    \While{$r\not=0$}\Comment{$r=0\mapsto\mbox{answer}$}
    \State $a\gets b$
    \State $b\gets r$
    \State $r\gets a\bmod b$
    \EndWhile\label{euclidendwhile1}
  \State \textbf{return} $b$\Comment{The GCD is $b$}
  \EndProcedure
\end{algorithmic}

\captionof{algorithm}{Euclid’s algorithm B}\label{euclidB}
\begin{algorithmic}[1]
  \Procedure{Euclid}{$a,b$}\Comment{GCD of $a$ and $b$}
    \State $r_2\gets a\bmod b$
    \While{$r\not=0$}\Comment{$r=0\mapsto\mbox{answer}$}
    \State $a\gets b$
    \State $b\gets r$
    \State $r\gets a\bmod b$
    \EndWhile\label{euclidendwhile2}
  \State \textbf{return} $b$\Comment{The GCD is $b$}
  \EndProcedure
\end{algorithmic}

\captionof{algorithm}{Euclid’s algorithm C}\label{euclidC}
\begin{algorithmic}[1]
  \Procedure{Euclid}{$a,b$}\Comment{GCD of $a$ and $b$}
    \State $r_3\gets a\bmod b$
    \While{$r\not=0$}\Comment{$r=0\mapsto\mbox{answer}$}
    \State $a\gets b$
    \State $b\gets r$
    \State $r\gets a\bmod b$
    \EndWhile\label{euclidendwhile3}
  \State \textbf{return} $b$\Comment{The GCD is $b$}
  \EndProcedure
\end{algorithmic}
\end{figure}

\lipsum[1-5]
\end{document}

You may have to adjust the space between the algorithmic and \captionof to suit your needs.

Best Answer

Related Solutions

[Tex/LaTex] Recursive algorithms with the »algorithms« package

[Tex/LaTex] 3 Algorithms in the same column with algorithmic

Related Question