Indenting lines of code in algorithm

Question

I am writting algorithm which has two stages. How can I indent code for stage one and for stage two?

\begin{algorithm}[H]
\caption*{my algorithm}
\begin{algorithmic}
    \STATE \textbf{Stage one:} this is stage one
    \FORALL{i}
        \STATE do something
    \ENDFOR
    \STATE \textbf{Stage two:} this is stage two
    \STATE Update the trie: 
    \FORALL{j}
    \STATE do something
    \ENDFOR
\end{algorithmic}
\end{algorithm}

score 27 · Answer 1 · answered Aug 25 '15 at 20:34

27

Define:

\algdef{SE}[SUBALG]{Indent}{EndIndent}{}{\algorithmicend\ }%
\algtext*{Indent}
\algtext*{EndIndent}

Then in the algorithmic block, write:

\begin{algorithmic}[1]
    \State Outside indent block
    \Indent
         \State Inside indent block
    \EndIndent
\end{algorithmic}

answered Aug 25 '15 at 20:34

mahdiz

387

2

I want this to work but the definition throws an error. – Caleb Stanford Jun 11 '18 at 05:42
Works for me without an error – someonr Feb 04 '20 at 17:20

Gonzalo Medina · Accepted Answer · 2012-09-01T21:55:14.747

17

In the following example code I defined two new commands allowing you to change the indentation; simply enclose the desired fragment using \bindent, \eindent; the length \myindent controls the indent amount:

\documentclass{article}
\usepackage{algorithm,algorithmic}
\usepackage{caption}

\newlength\myindent
\setlength\myindent{2em}
\newcommand\bindent{%
  \begingroup
  \setlength{\itemindent}{\myindent}
  \addtolength{\algorithmicindent}{\myindent}
}
\newcommand\eindent{\endgroup}

\begin{document}

\begin{algorithm}[H]
\caption*{my algorithm}
\begin{algorithmic}
    \STATE \textbf{Stage one:} this is stage one
    \bindent
    \FORALL{i}
        \STATE do something
    \ENDFOR
    \eindent
    \STATE \textbf{Stage two:} this is stage two
    \bindent
    \STATE Update the trie: 
    \FORALL{j}
    \STATE do something
    \ENDFOR
    \eindent
\end{algorithmic}
\end{algorithm}

\end{document}

enter image description here

Some comments to the code:

\newlength\myindent % define a new length \myindent
\setlength\myindent{6em} % assign the length 2em to \myindet
\newcommand\bindent{%
  \begingroup % starts a group (to keep changes local)
  \setlength{\itemindent}{\myindent} % set itemindent (algorithmic internally uses a list) to the value of \mylength
  \addtolength{\algorithmicindent}{\myindent} % adds \mylength to the default indentation used by algorithmic
}
\newcommand\eindent{\endgroup} % closes a group

edited Sep 01 '12 at 21:55

answered Sep 01 '12 at 21:39

Gonzalo Medina

505,128

this is perfect, just curious what does this line \newlength\myindent mean? – ashim Sep 01 '12 at 21:48
could you add some comment explaining what does each line do? thank you – ashim Sep 01 '12 at 21:50
@capoluca sure! I've updated my answer adding some comments. – Gonzalo Medina Sep 01 '12 at 21:55
13

I'm getting an error with your approach: ! You can't use 'the character 1' after \advance. \ALG@cmd@2@algorithmicindent ->1 .5em l.21 \bindent
But @mahdiz solution worked
– Ciprian Tomoiagă Apr 28 '16 at 02:23
1

Thank you, it indeed generates indentation, but the line number of code also indents. How can I fix it? This answer can help: https://tex.stackexchange.com/a/333962/83288 – GoingMyWay Jan 14 '19 at 02:51
This will also indent the line number of the algorithm! – Instein Aug 25 '22 at 04:28

score 13 · Answer 3 · edited Oct 13 '16 at 12:24

Problem of Gonzalo's answer is with numbering, as numbers are also indented.

Found better and also simpler solution for \algorithmic, the inbuild environment ALC@g

\begin{ALC@g}
   % Indent what you need
\end{ALC@g}

To compare it in same document

\newlength\myindent
\setlength\myindent{2em}
\newcommand\bindent{%
    \begingroup
    \setlength{\itemindent}{\myindent}
    \addtolength{\algorithmicindent}{\myindent}
}
\newcommand\eindent{\endgroup}

\begin{algorithmic}[1]
    \STATE \textbf{Gonsalo's answer}
    \bindent
    \STATE First
    \STATE Second 
    \eindent
    \STATE \textbf{Proposed answer}

    \begin{ALC@g}
        \STATE First
        \STATE Second 
    \end{ALC@g}
    \STATE Something else
\end{algorithmic}

And result

Test

Of course you can include solution for bigger indent with \addtolength and \setlength inside my proposal.

Your answer is the best working one. Good, it avoids generating line number indentations. BTW, how can I set the indentation spaces? In your answer, it indents only one space. — GoingMyWay, Jan 14 '19 at 02:56

score 11 · Answer 4 · answered Dec 31 '18 at 00:46

11

If you want to be flexible with the indentation size you can also quickly use \hskip1.0em:

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

\begin{document}

\begin{algorithm}[H]
    \caption{Foos}
    \begin{algorithmic}[1]
        \State foo
        \State \hskip0.5em foo
        \State \hskip1.0em foo
        \State \hskip1.5em foo
    \end{algorithmic}
\end{algorithm}

\end{document}

answered Dec 31 '18 at 00:46

Finn

233

1

This worked like a charm, thank you! – user3480922 Apr 18 '21 at 08:25

score 3 · Answer 5 · edited Apr 23 '20 at 20:27

3

If you use the algorithm2e package, the answer is \Indp and \Indm. The first creates indent and the second creates negative indent, thus removes the previously created one. See this answer for more details.

edited Apr 23 '20 at 20:27

AvidLearner

535

answered Mar 02 '20 at 12:15

SiGa

369

3

(In favor of those coming from Google): This answer is excellent for algorithm2e. Seek no more! – AvidLearner Apr 23 '20 at 19:57

Indenting lines of code in algorithm

5 Answers5

Linked

Related