[Tex/LaTex] ! Undefined control sequence. \Procedure

algorithmicalgorithms

I follow http://shantoroy.com/latex/how-to-write-algorithm-in-latex/ and https://www.overleaf.com/read/rddymzwmnqgb

I have

\begin{algorithm}
\caption{Put your caption here}

\begin{algorithmic}[1]

\Procedure{Roy}{$a,b$}       \Comment{This is a test}
    \State System Initialization
    \State Read the value 
    \If{$condition = True$}
        \State Do this
        \If{$Condition \geq 1$}
        \State Do that
        \ElsIf{$Condition \neq 5$}
        \State Do another
        \State Do that as well
        \Else
        \State Do otherwise
        \EndIf
    \EndIf

    \While{$something \not= 0$}  \Comment{put some comments here}
        \State $var1 \leftarrow var2$  \Comment{another comment}
        \State $var3 \leftarrow var4$
    \EndWhile  \label{roy's loop}
\EndProcedure

\end{algorithmic}
\end{algorithm}

Error

! Undefined control
sequence. \Procedure

How to fix it?

Best Answer

I am missing

\usepackage[noend]{algpseudocode}

Related Solutions

[Tex/LaTex] Why does the placement of a \COMMENT in the algorithmic enviroment matter

You need to "fool" the algorithmic environment into posting just a comment on a line via \STATE \COMMENT{Blah}. The reason for this (in answer to your first question) is because the algorithmic environment handles it's contents like a list (similar to \begin{enumerate}...\end{enumerate} or \begin{itemize}...\end{itemize}). And, in a similar context, it requires a command like \item to move to the next item, or even start the list. Such a command is \STATE. That, with the following minimal example should answer both questions:

\documentclass[a4paper,10pt]{article}
\usepackage{algorithmic}
\begin{document}
\begin{algorithmic}
\FORALL{$a \in B$}
    \STATE \COMMENT{Blah.} % single line comment
    \STATE X
    \COMMENT{Blah.}
\ENDFOR
\end{algorithmic}
\end{document}

Algorithmic with line comment

EDIT: The above only works if you do not use line numbers. If you do use line numbers (via \begin{algorithmic}[1]), then you can define a new macro \LCOMMENT{<comment>} (short for "Line COMMENT") that does the trick:

\documentclass[a4paper,10pt]{article}
\usepackage{algorithmic}
\makeatletter
\newcounter{ALC@tempcntr}% Temporary counter for storage
\newcommand{\LCOMMENT}[1]{%
    \setcounter{ALC@tempcntr}{\arabic{ALC@rem}}% Store old counter
    \setcounter{ALC@rem}{1}% To avoid printing line number
    \item \{#1\}% Display comment + does not increment list item counter
    \setcounter{ALC@rem}{\arabic{ALC@tempcntr}}% Restore old counter
}%
\makeatother
\begin{document}
\begin{algorithmic}[1]
\FORALL{ $a \in B$}
    \LCOMMENT{Blah.} % single line comment
    \STATE X
    \COMMENT{Blah.}
\ENDFOR
\end{algorithmic}
\end{document}

Algorithmic with line comment without line number

There may be other/better/more elegant solutions as well.

[Tex/LaTex] Algorithm and IEEEtran

The IEEEtran's documentation suggests:

B. Algorithms

IEEE publications use the figure environment to contain algorithms that are not to be a part of the main text flow. Peter Williams’ and Rogerio Brito’s algorithmic.sty package [24] or Szász János’ algorithmicx.sty package [25] (the latter is designed to be more customizable than the former) may be of help in producing algorithm-like structures (although authors are of course free to use whatever LaTeX commands they are most comfortable with in this regard). However, do not use the floating algorithm environment of algorithm.sty (also by Williams and Brito) or algorithm2e.sty (by Christophe Fiorio) as the only floating structures IEEE uses are figures and tables. Furthermore, IEEEtran will not be in control of the (non-IEEE) caption style produced by the algorithm.sty or algorithm2e.sty float environments.

So, as suggested, do not use the algorithm floating environment; you can wrap your algorithm inside a figure (or figure*) environment (if a caption is required and the captions are to be IEEEtran compliant) and use the algorithmicx package ; something like this:

\documentclass{IEEEtran}
\usepackage{algpseudocode}

\begin{document}

\begin{figure}
\begin{algorithmic}[1]
\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
\end{algorithmic}
\caption{Euclid's algorithm}\label{euclid}
\end{figure}

\end{document}

enter image description here

If no caption is required, then simply don't use the figure environment.

Best Answer

Related Solutions

[Tex/LaTex] Why does the placement of a \COMMENT in the algorithmic enviroment matter

[Tex/LaTex] Algorithm and IEEEtran

Related Question