[Tex/LaTex] Writing an algorithm in LaTeX

algorithmicxalgorithmsindentation

Enter image description here

I am trying to write an algorithm in LaTeX. I used a for loop inside the algorithm (see attached image), but the problem is that the statements that are below the for loop are not tapped. Why?

I used the packages \usepackage{algorithm} and \usepackage{algpseudocode}.

This the code I wrote:

\begin{algorithm}
\caption{CH election algorithm}
\label{CHalgorithm}
\begin{algorithmic}[1]
\Procedure{CH\textendash Election} {}
\For{each node $i$ \Pisymbol{psy}{206} $N$ }
\\Broadcast HELLO message to its neighbor
\\let $k$ \Pisymbol{psy}{206} $N1$ ($i$) U {$i$} be s.t
\\QOS($k$) = max {QOS($j$) \textbar $j$ \Pisymbol{psy}{206} $N1$($i$)  U $i$}
\\ MPRSet($i$) = $k$
\EndFor
\EndProcedure
\end{algorithmic}
\end{algorithm}

Best Answer

You have to use \State instead of \\ to indent your lines inside the \For statement.

MWE

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

\begin{document}
\begin{algorithm}
\caption{CH election algorithm}
\label{CHalgorithm}
\begin{algorithmic}[1]
\Procedure{CH\textendash Election}{}
\For{each node $i$ \Pisymbol{psy}{206} $N$ }
\State Broadcast HELLO message to its neighbor
\State let $k$ \Pisymbol{psy}{206} $N1$ ($i$) U {$i$} be s.t
\State QOS($k$) = max {QOS($j$) \textbar $j$ \Pisymbol{psy}{206} $N1$($i$)  U $i$}
\State MPRSet($i$) = $k$
\EndFor
\EndProcedure
\end{algorithmic}
\end{algorithm}
\end{document}

Result:

enter image description here

Related Solutions

[Tex/LaTex] Algorithm in LaTeX

It is not completely clear to me which algorithm typesetting package are you using, since you did not include the document preamble, and your code is a strange jumble of several different syntaxes, mostly looking like the old algorithms package syntax, but not quite. Your tags seem to indicate that you are using the algorithmicx bundle, so I assume that you use the algpseudocode package. You need to correct some syntax, for example algpseudocode does noy capitalize command, only first letter, so you should have \If ... \Else ... \EndIf etc.

Also, command \For and \If take an argument, so you need

\If{something something}

The \If does not use \Then, you should leave that out.

Every line must have a command, so you should either define your own commands for things like "Given:", or just use \State.

The following will hopefully do what you expect it to do:

\documentclass{article}
\usepackage{algpseudocode}
\usepackage{algorithm}
\begin{document}
\begin{algorithm}
   \caption{Blah blah}
   \begin{algorithmic}[1]
      \State Given: User-Noun Matrix $X$
      \For{$i = 1 \to n$}
         \State Let $S_i$ = {$s{i,j}$ | $0\le j \le l_i$} be set of nodes which have links to $i$;
         \If{$\left(l_i=0 \hbox{OR} l_i=1 \right)$}
            \State $b_i=0$;
         \Else
            \State Compute the similarity score vectors $r_{s,1},r_{s,2},...,r_{s,l_i}$ for each $S_i=s_1,s_2,...s_{l_i}$; \\
            \State Construct $l_i \times l_i$ matrix $R_i= \left[r_{s,1},r_{s,2},...,r_{s,l_i}\right]$;
            \State Take the average of all non-diagonal elements in $R_i$ to obtain $\hat{r_s}$;
            \State $b_i= 1/\hat{r_s}$;
         \EndIf
      \EndFor
    \State \Return vector $b$ of bridging scores;
\end{algorithmic}
\end{algorithm}
\end{document}

The algorithmicx bundle have pretty good documentation with a number of examples, I suggest you take a look at it.

[Tex/LaTex] Slight change in algorithm

Here's an option that provides feasible output. I've removed the physical numbering in the caption:

enter image description here

\documentclass[10pt,twocolumn]{article}
\usepackage{algorithm,algpseudocode}% http://ctan.org/pkg/{algorithms,algorithmx}
\algnewcommand{\Inputs}[1]{%
  \State \textbf{Inputs:}
  \Statex \hspace*{\algorithmicindent}\parbox[t]{.8\linewidth}{\raggedright #1}
}
\algnewcommand{\Initialize}[1]{%
  \State \textbf{Initialize:}
  \Statex \hspace*{\algorithmicindent}\parbox[t]{.8\linewidth}{\raggedright #1}
}

\begin{document}
\begin{algorithm}
  \caption{Boosted $K$ Nearest Neighbour}
  \begin{algorithmic}[1]
    \Inputs{$S={s_i}=\left(x_i,y_i\right)$}
    \Initialize{\strut$w_i^0 \gets 0$, $i=1,\ldots,n$ \\ $S_0 \gets S$}
    \For{t = 1 to T}
      \State $S_t \gets S_{t-1}$
      \For{$s_q \in S_t$}
        \State $N_q \gets$ k nearest neighbors 
        \State of $s_q$ using $D(s_q,s_i)$
        \State label($s_q$)$=argmax\sum_{s_i \in N_q}D(s_q,s_i)$;
        \If{label($s_q$)$\ne y_q$}
          \For{$s_i \in N_i$}
            \If{$y_i \ne y_q$}
              \State $w_{i}^{t} \gets w_{i}^{t} - \lambda/d(x_q,x_i)$;
            \Else
              \State $w_{i}^{t} \gets w_{i}^{t} + \lambda/d(x_q,x_i)$;
            \EndIf
          \EndFor
        \EndIf
      \EndFor
      \If{label($s_q$)$=y_q \forall_{s_q}$}
        \State break
      \EndIf
    \EndFor
  \end{algorithmic}
\end{algorithm}
\end{document}

A newly-defined \Inputs and (equivalent) \Initialize takes one argument that sets its contents in a \Statex with an indent of \algorithmicindent - the default - to align with the other algorithm elements. The contents is stored in a top-aligned \parbox that fits across 80% of the line. I'm sure you won't need more, but in case you do, that can also be fixed to not cause overfull boxes.

Best Answer

Related Solutions

[Tex/LaTex] Algorithm in LaTeX

[Tex/LaTex] Slight change in algorithm

Related Question