# Difference between revisions of "Elsarticle.cls"

## Introduction

elsarticle.cls is a thoroughly rewritten document class for formatting LaTeX submissions to Elsevier journals. The class uses the environments and commands defined in LaTeX kernel without change to the signature so that clashes with other contributed LaTeX packages like hyperref.sty, preview-latex.sty, etc., will be minimal. elsarticle.cls is primarily built upon the default article.cls. The class depends on the following packages for its proper functionality:

1. pifont.sty for openstar in the title footnotes.
2. natbib.sty for citation processing.
3. geometry.sty for margin settings.
4. fleqn.clo for left aligned equations.
5. graphicx.sty for graphics inclusion.
6. txfonts.sty optional font package, if document is to be formatted with Times and compatible math fonts.
7. hyperref.sty optional packages if hyper linking is required in the document.

All the above packages are part of any standard LaTeX installation. Therefore, the users need not be bothered about downloading any extra packages. Further, users are free to make use of AMS math packages like, amsmath.sty, amsthm.sty, amssymb.sty, amsfonts.sty, etc., if they want. All these packages work in tandem with elsarticle.cls without any problems.

## Major Differences

Following are the major differences between elsarticle.cls and its predecesor package, elsart.cls:

• elsarticle.cls is built upon article.cls while elsart.cls is not. elsart.cls redefines many of the commands in the LaTeX classes/kernel, which can possibly cause surprising clashes with other contributed LaTeX packages.
• Provides preprint document formatting by default, and optionally formats the document as per the final style of models 1+, 3+ and 5+ of Elsevier journals.
• Some easier hooks for formatting list and theorem environments are provided while people can still use amsthm.sty package.
• natbib.sty is the main citation processing package which can comprehensively handle all kinds of citations and works perfectly with hyperref.sty in combination with hypernat.sty.
• Long title pages are processed correctly in preprint and final formats.

## Installation

The package is available at author resources page at Elsevier Science. It can also be found in any of the nodes of the Comprehensive TeX Archive Network (CTAN), one of the primary nodes being http://www.ctan.org. Please grab the elsarticle.dtx which is the composite class with documentation and elsarticle.ins which is the LaTeX installer file. When we compile the elsarticle.ins with LaTeX it provides the class file, elsarticle.cls by stripping off all the documentation from the *.dtx file. The class may be moved or copied to a place, usually, \$TEXMF/tex/latex/elsevier/, or a folder which will be read by LaTeX during document compilation. The TeX file database needs updation after moving/copying class file. Usually, we use commands like mktexlsr or texhash depending upon the distribution and operating system.

## Usage

The class should be loaded with the command: <geshi lang="latex">

\documentclass[<options>]{elsarticle}


</geshi> where the options can be the following:

preprint
default options which formats the document for submission to Elsevier journals.
review
similar to preprint option, but increases the baselineskip to facilitate easier review process.
1p
formats to the look and feel of the final format of model 1+ journals. This is always single column style.
3p
formats to the look and feel of the final format of model 3+ journals. If the journal is a two column model use twocolumn option in combination.
5p
formats for model 5+ journals. This is always two column style.
authoryear
author-year citation style of natbib.sty. If you want to add extra options of natbib.sty, you may use the options as a comma delimited strings as argument to \biboptions command. An example would be:

<geshi lang="latex">

\biboptions{longnamesfirst,angle,semicolon}


</geshi>

number
numbered citation style. Extra options can be loaded with \biboptions command.
sort&compress
sorts and compresses the numbered citations. Example, citation [1,2,3] will become [1-3].
longtitle
if front matter is unusually long, use this option to split the title page across pages with correct placing of title and author footnotes in the first page.
times
loads txfonts.sty if available in the system to use Times and compatible math fonts.
• All options of article.cls can be used with this document class.
• The default options loaded are a4paper, 10pt, oneside, onecolumn and preprint.

## Front matter

There are two types of front matter coding — (1) each author is connected to an affiliation with a footnote marker; hence all authors are grouped together and affiliations follow; (2) authors of same affiliations are grouped together and the relevant affiliation follows this group. An example coding of the first type is provided below:

<geshi lang="latex"> \begin{frontmatter}

\title{This is a specimen title\tnoteref{t1,t2}}
\tnotetext[t1]{This document is a collaborative effort.}
\tnotetext[t2]{The second title footnote which is a longer
longer than the first one and with an intention to fill
in up more than one line while formatting.}

\author[rvt]{C.V.~Radhakrishnan\corref{cor1}\fnref{fn1}}

\author[rvt,focal]{K.~Bazargan\fnref{fn2}}

\author[els]{S.~Pepping\corref{cor2}\fnref{fn1,fn3}}

\cortext[cor1]{Corresponding author}
\cortext[cor2]{Principal corresponding author}
\fntext[fn1]{This is the specimen author footnote.}
\fntext[fn2]{Another author footnote, but a little more longer.}
\fntext[fn3]{Yet another author footnote. Indeed, you can have
any number of author footnotes.}

\address[rvt]{River Valley Technologies, SJP Building,
Cotton Hills, Trivandrum, Kerala, India 695014}
\address[focal]{River Valley Technologies, 9, Browns Court,
Kennford, Exeter, United Kingdom}
Amsterdam, Netherlands}


. . . . . . \end{frontmatter} </geshi>

Output of the above TeX sources will look like the following:

Most of the commands like \title, \author, \address are self explanatory. Various components are linked each other by a label–reference mechanism, for instance, title footnote is linked to the title with a footnote mark generated by referring to the \label string of the \tnotetext. We have used similar commands like \tnoteref (to link title note to title); \corref (to link corresponding author text to corresponding author); \fnref (to link footnote text to the relevant author names). TeX needs two compilations to resolve the footnote marks in the preamble part. Given below are the syntax of various note marks and note texts. <geshi lang="latex">

\tnoteref{<label(s)>}
\corref{<label(s)>}
\fnref{<label(s)>}
\tnotetext[<label>]{<title note text>}
\cortext[<label>]{<corresponding author note text>}
\fntext[<label>]{<author footnote text>}


</geshi> where <label(s)> can be either one or more comma delimited label strings. The optional arguments to the \author command holds the ref label(s) of the address(es) to which the author is affiliated while each \address command can have an optional argument of a label. In the same manner, \tnotetext, \fntext, \cortext will have optional arguments as their respective labels and note text as their mandatory argument.

The following example code provides the markup of the second type of author-affiliation. <geshi lang="latex"> \author{C.V.~Radhakrishnan\corref{cor1}\fnref{fn1}}

\ead{cvr@river-valley.com}
Cotton Hills, Trivandrum, Kerala, India 695014}


</geshi> <geshi lang="latex"> \author{K.~Bazargan\fnref{fn2}}

\ead{kaveh@river-valley.com}
\address{River Valley Technologies, 9, Browns Court, Kennford,
Exeter, United Kingdom}


</geshi> <geshi lang="latex"> \author{S.~Pepping\fnref{fn1,fn3}}

\ead[url]{http://www.elsevier.com}
Elsevier, Radarweg 43, 1043 NX Amsterdam, Netherlands}


</geshi> <geshi lang="latex"> \cortext[cor1]{Corresponding author} \fntext[fn1]{This is the first author footnote.} \fntext[fn2]{Another author footnote, this is a very long footnote and

  it should be a really long footnote. But this footnote is not yet
sufficiently long enough to make two lines of footnote text.}


\fntext[fn3]{Yet another author footnote.} </geshi> Output of the above TeX sources will look like the following:

The front matter part has further environments like \begin{abstract} . . . \end{abstract} and \begin{keyword} ... \end{keyword} which contain the abstract and keywords respectively. Keywords can be marked up in the following manner: <geshi lang="latex"> \begin{keyword}

 quadruple exiton \sep polariton \sep WGM
\PACS 71.35.-y \sep 71.35.Lk \sep 71.36.+c


\end{keyword} </geshi> Each keyword shall be separated by \sep command. PACS and MSC classifications shall be provided in the keyword environment with the commands \PACS and \MSC respectively. \MSC accepts an optional argument to accommodate future revisions. eg., \MSC[2008]. The default is 2000.

### Specimen of a title page coding

Following is the specimen of a title page coding. <geshi lang="latex"> \documentclass[preprint,1p,12pt]{elsarticle}

\journal{Nuclear Physics B}

\begin{document}

\begin{frontmatter}

\title{This is a specimen title\tnoteref{t1,t2}}

\tnotetext[t1]{This document is a collaborative effort.}
\tnotetext[t2]{The second title footnote which is a longer
longer than the first one and with an intention to fill
in up more than one line while formatting.}

\author[rvt,focal]{K.~Bazargan\fnref{fn2}}

\author[els]{S.~Pepping\corref{cor2}\fnref{fn1,fn3}}

\cortext[cor1]{Corresponding author}
\cortext[cor2]{Principal corresponding author}
\fntext[fn1]{This is the specimen author footnote.}
\fntext[fn2]{Another author footnote, but a little more longer.}
\fntext[fn3]{Yet another author footnote. Indeed, you can have
any number of author footnotes.}

Cotton Hills, Trivandrum, Kerala, India 695014}
\address[focal]{River Valley Technologies, 9, Browns Court,
Kennford, Exeter, United Kingdom}
Amsterdam, Netherlands}


\begin{abstract} In this work we demonstrate the formation of a new type of polariton on the interface between a cuprous oxide slab and a polystyrene micro-sphere placed on the slab. ..... \end{abstract}

\begin{keyword}

 quadruple exiton \sep polariton \sep WGM
\PACS 71.35.-y \sep 71.35.Lk \sep 71.36.+c


\end{keyword}

\end{frontmatter}

\section{Introduction}\label{sec1} Although quadrupole excitons (QE) in cuprous oxide crystals are good candidates for BEC ...... </geshi>

## Floats

Figures may be included using the command, \includegraphics in combination with or without its several options to further control the graphic. \includegraphics is provided by graphic[s,x].sty which is part of any standard LaTeX distribution. graphicx.sty is loaded by default. LaTeX accepts figures in postscript format while pdfLaTeX accepts *.pdf, *.mps (metapost), *.jpg and *.png formats. pdfLaTeX does not accept graphic files in postscript format.

The table environment is handy for marking up tabular material. If users want to use multirow.sty, array.sty, etc., to fine control/enhance the tables, they are welcome to load any package of their choice and elsarticle.cls will work in combination with all loaded packages.

## Theorem and theorem like environments

elsarticle.cls provides a few hooks to format theorems and theorem like environments with ease. In all commands the options that are used with \newtheorem command will work exactly in the same manner. elsarticle.cls provides three commands to format theorem or theorem like environments: <geshi lang="latex"> \newtheorem{thm}{Theorem} \newtheorem{lem}[thm]{Lemma} \newdefinition{rmk}{Remark} \newproof{pf}{Proof} \newproof{pot}{Proof of Theorem \ref{thm2}} </geshi>

\newtheorem command formats a theorem in LaTeX's default style with italicized font, bold font for theorem heading, theorem number at the right hand side of the theorem heading. It also optionally accepts an argument which will be printed as an extra heading in parentheses. The following text will show you how some text enclosed between \begin{thm} . . . \end{thm} will look like.

\newdefinition command is same in all respects as its \newtheorem counterpart except that the font shape is roman instead of italic. Both \newdefinition and \newtheorem commands automatically defines counters for the environments defined. See the output of of \begin{rmk} . . . \end{rmk} which is given below.

\newproof command is for defining proof environments with upright font shape. No counters are defined. See the output of \begin{pot} . . . \end{pot} which is given below.

Users can also make use of amsthm.sty which will override all the default definitions described above.

## Enumerated and Itemized Lists

elsarticle.cls provides an extended list processing macros which makes the usage a bit more user friendly than the default LaTeX list macros. With an optional argument to the \begin{enumerate} command, you can change the list counter type and its attributes. <geshi lang="latex"> \begin{enumerate}[1.] \item The enumerate environment starts with an optional argument 1.' so that the item counter will be suffixed by a period. \item If you provide a closing parenthesis to the number in the optional argument, the output will have closing parenthesis for all the item counters. \item You can use (a)' for alphabetical counter and '(i)' for roman counter.

\begin{enumerate}[a)]
\item Another level of list with alphabetical counter.
\item One more item before we start another.
\begin{enumerate}[(i)]
\item This item has roman numeral counter.
\item Another one before we close the third level.
\end{enumerate}
\item Third item in second level.
\end{enumerate}


\item All list items conclude with this step. \end{enumerate} </geshi>

The typeset copy of the above source code is given below:

Further, the enhanced list environment allows one to prefix a string like step' to all the item numbers. Take a look at the example below: <geshi lang="latex"> \begin{enumerate}[Step 1.]

\item This is the first step of the example list.
\item Obviously this is the second step.
\item The final step to wind up this example.


\end{enumerate} </geshi> The typeset copy of the above source code is given below:

## Cross-references

In electronic publications articles may be internally hyperlinked. Hyperlinks are generated from proper cross-references in the article. For example, the words Fig. 1 will never be more than simple text, whereas the proper cross-reference \ref{tiger} may be turned into a hyperlink to the figure itself: Fig. 1. In the same way, the words Ref. [1] will fail to turn into a hyperlink; the proper cross-reference is \cite{Knuth96}. Cross-referencing is possible in LaTeX for sections, subsections, formulae, figures, tables, and literature references.

## Mathematical symbols and formulae

Many physical/mathematical sciences authors require more mathematical symbols than the few that are provided in standard LaTeX. A useful package for additional symbols is the amssymb package, developed by the American Mathematical Society. This package includes such oft used symbols as \lesssim for ******, \gtrsim for ***** or \hbar for *****. Note that your TeX system should have the msam and msbm fonts installed. If you need only a few symbols, such as \Box for *****, you might try the package latexsym.

Another point which would require authors' attention is the breaking of longer equations. When you use elsarticle.cls for formatting your submissions in preprint mode, the document is formatted in single column style with a text width of 384pt or 5.3in. When this document is formatted for final print and if the journal happens to be a double column journal, the text width will be reduced to 224pt at for 3+ double column and 5+ journals respectively. All the nifty fine tuning in equation breaking done by the author goes to waste in such cases. Therefore, authors are requested to check this problem by typesetting their submissions in final format as well just to see if their equations are broken at appropriate places, by changing appropriate options in the document class loading command, which is explained in section 4, Usage. This allows authors to fix any equation breaking problem before submission for publication. elsarticle.cls supports formatting the author submission in different types of final format. This is further discussed in section 12, Final print.

## Bibliography

Three bibliographic style files (*.bst) are provided -- elsarticle-num.bst<code>, <code>elsarticle-num-names.bst and elsarticle-harv.bst -- the first one for numbered scheme, the second for numbered with new options of natbib.sty and the last one for author year scheme.

In LaTeX literature references are listed in the thebibliography environment. Each reference is a \bibitem; each \bibitem is identified by a label, by which it can be cited in the text: \bibitem[Elson et al.(1996)]{ESG96} is cited as \citet{ESG96}. In connection with cross-referencing and possible future hyperlinking it is not a good idea to collect more than one literature item in one \bibitem. The so-called Harvard or author-year style of referencing is enabled by the LaTeX package natbib. With this package the literature can be cited as follows:

• Parenthetical: \citep{WB96} produces (Wettig & Brown, 1996).
• Textual: \citet{ESG96} produces Elson et al. (1996).
• An affix and part of a reference: \citep[e.g.][Ch. 2]{Gea97} produces (e.g. Governato et al., 1997, Ch. 2).

In the numbered scheme of citation, \cite{<label>} is used, since \citep or \citet has no relevance in numbered scheme. natbib package is loaded by elsarticle with numbers as default option. You can change this to author-year or harvard scheme by adding option authoryear in the class loading command. If you want to use more options of the natbib package, you can do so with the \biboptions command, which is described in section 4, Usage. For details of various options of the natbib package, please take a look at the natbib documentation, which is part of any standard LaTeX installation.

## Final print

Authors can format their submission to the page size and margins of their preferred journal. elsarticle provides four class options for the same:

1p
1+ journals with a text area of 384pt × 562pt or 13.5cm × 19.75cm or 5.3in × 7.78in, single column style only.
3p
3+ journals with a text area of 468pt × 622pt or 16.45cm × 21.9cm or 6.5in × 8.6in, single column style.
3pd
3+ with the same text area as above, double column style.
5p`
5+ with text area of 522pt × 682pt or 18.35cm × 24cm or 7.22in × 9.45in, double column style only.

Following is the first page of a typical single column article.

Model 1+ and 3+ will have the same look and feel in the typeset copy when presented in this document. That is also the case with the double column 3+ and 5+ journal article pages. The only difference will be wider text width of higher models. Therefore we will look at the different portions of a typical single column journal page and that of a double column article in the final format.

Following is the first page of a typical double column article.

## Displayed equations and double column journals

Many Elsevier journals print their text in two columns. Because the preprint layout uses a larger line width than such columns, the formulas are too wide for the line width in print. Here is an example of an equation (see equation 6) which is perfect in single column preprint format:

When this document is typeset for publication in a model 3+ journal with double columns, the equation will overlap the second column text matter if the equation is not broken at the appropriate location.

The typesetter will try to break the equation which need not necessarily be to the liking of the author or as it happens, typesetter's break point may be semantically incorrect. Therefore, authors may check their submissions for the incidence of such long equations and break the equations at the correct places so that the final typeset copy will be as they wish.