What's LaTeX all about?

Rein Smedinga

Introduction

LaTeX is a text formatting program, i.e., after you have written a text into a file by means of an editor, the LaTeX-program converts this text into printable matter. With LaTeX you cannot do what-you-see-is-what-you-get work: you need two steps: one editing step in which you type in the text together with typesetting commands into a file; and one formatting step, in which the program converts the text, according to the given commands, in printable code.

The following steps have to be done:

1. Creation of a text file with text and LaTeX commands. Creation is done using a text editor (any editor will do). For example, you can use the editor emacs:

       emacs example.tex
   

   The UNIX command above starts the editor and creates the file example.tex. You should always give the file a name with extension .tex (otherwize LaTeX will not recognize the file as a text file).
2. Converting this file to printable code. Here the LaTeX-program does the job:

       latex example
   

   It is not necessary to give the filename extension here. LaTeX now creates some additional files. One of these is the file example.dvi,that can be printed and previewed. Also example.aux is created (needed for cross referencing) and example.log in which LaTeX writes down a log of everything it has done.

   Because each language has its own hyphenation-rules, you can use other rules than English hyphenation by giving special commands in the file. We will return to this subject later on.

3. Previewing the document. By typing:

       xdvi example
   

   the file example.dvi will be previewed on your screen.
4. Printing the document. By typing:

   lp -d printername example.dvi

   your document will be printed. For printername fill in: x for the Xerox printer on the ground floor, or lj4 for the HP laserjet printer on the first floor.

A document in LaTeX

As stated before, the original text file example.tex should not only contain text, but also LaTeX-commands. First of all, you need to explain what kind of document you want to make, and you should indicate the beginning and the end of the included text. This is done by typing on the first lines of your text-file the following:

\documentclass{article}
\begin{document}

The second line tells LaTeX that after this line your real document starts. At the end of that document, you should add the following line:

\end{document}

A very simple article could be:

Between \documentclass and {article} you can put all kind of options to change the documentclass a little bit. For example, by:

\documentclass[a4paper]{article}

Another possibility is to add extra tools. This is done by adding (after the documentclass-line) lines like:

\usepackage{epsf}
\usepackage[dutch]{babel}

Another possibility to use here is the option to enlarge the used font a little bit. Instead of standard 10 pt. fonts you can use 11 pt. fonts by starting with:

\documentclass[11pt]{report}

\documentclass[12pt,a4paper]{book}

Commands in LaTeX

In order to create a textfile, it will now be clear that the actual text has to be put between \begin{document} and \end{document}. However, in typing your text, you should be aware, that some characters have special meaning. We mention

{ } \ # $ % &

\{ \} \backslash \$ \% \&

Commonly used commands are those to denote the beginning of a new chapter, new section, etc. We mention a few:

• Start of a new chapter (only available in report and book style, not in article style):

  \chapter{name}
  

  name becomes the title of the new chapter. Chapter numbering and adding the word chapter itself (or hoofdstuk, if the dutch option is used) is done automatically.
• Start of a new section:

  \section{name}
  

  name is the title of the new section. Also here, numbering is done automatically.
• Subsections:

  \subsection{name}
  

  Etc.
• Start of a new paragraph: Just including an empty line forces a new paragraph to be started. Most document styles have the first line of a new paragraph indented.
• Start of a new line:

  end of a line.\\ 
  start of a next line...
  

  A newline command \\ only works if a line can really be closed. So \\ \\ is not allowed. The second \\ does not close a real line.
• Enumeration:

  

  With \item a new item will be started. Automatically, a marker will be put before that item and the whole item will be indented. If you want to number the items, you should use:

  

  Numbering is done automatically. Itemize and enumerate lists can be nested and mixed.

• Title of an article.
  Title, author(s), and date can be defined using:

  \title{This is the title}
  \author{A. Writer and B. Reader}
  \date{tomorrow or so}
  

  and will be printed if you say:

  \maketitle
  

  In the article style the title and author-list will appear above the text, in report and book style it will be put on a separate page.
• Table of contents. To get a contents type the following command right there, where you want to have the contents:

  \tableofcontents
  

  This command creates an additional file, with extension .toc, that is read in the second time, you process your document through LaTeX, to create the table of contents. So, you need to give the UNIX command

      latex example
  

  twice, to really get the (up to date) contents.

Accents

Some commonly used accents are:

be\"eindigen

be\"\i nvloed

\'e\'en

Other fonts

The used font can be changed to for example boldface or italics by typing:

\textbf{this will be printed boldface} and this in normal font
\emph{and this emphasized} and normal again and \textsl{slanted} and
\textit{italics} and so on.

larger

{\tiny very small text}
{\footnotetext Quite small text}
{\small Small text} 
{\normalsize is normally not used}
{\large Larger text}
{\LARGE Even larger text}
{\Huge Very huge text}

\tiny \scriptsize \footnotesize \small \normalsize 
\large \Large \LARGE \huge \Huge

Tables

LaTeX provides easy to use commands to create tables. For example:

The argument after \begin{tabular} defines the structure of the table. Each letter represents a column. A l means a left alined column, a c means a centered column, and a r means a right alined column. Also possible is to put a | there, to define a vertical line between columns. The contents of each part of the table is separated by & and each line is ended by \\ . Much more complex tables are possible. The reader is adviced to look in the LaTeX-manual, [Lam94], for more examples.

Floating text

Floating text is text that can be put somewhere in the text, but has no specific place within the text. For example figures and tables can be floats. They should be put near the place the figure or table is discussed. Such floats can be created in LaTeX by typing:

\begin{figure}
Figure text...
\caption{Figure title}
\end{figure}

\begin{table}
Table text...
\caption{Figure title}
\end{table}

Formulaes

A mathematical formula is put between $. For example:

Subscripts are defined using _ and superscripts using ^. If more characters are to be sub/superscripted, these should be put between accolades, e.g. compare:

For displayed formulaes, we use:

Displayed formulaes are put on a separate line and centered. \sum is the summation symbol. In [Lam94] long lists of symbols can be found.

And many more...

The reader is adviced to read the LaTeX-manual [Lam94] to explore LaTeX. Sample text files exists, to get a first impression on LaTeX, for example try:

    cp /usr/local/teTeX/texmf/tex/latex/base/sample2e.tex .
    latex sample2e
    xdvi sample2e

Errors in your LaTeX document

If some error occurs in your document, you get an error message on the screen. Something like:

! Undefined control sequence.
l.22 ...eation of a text file with text and \LateX
                                                  \ commands. Creation is
?

References

GMS94

M. Goossens, F. Mittelbach, and A. Samarin. The LaTeX companion. Addison Wesley, 1994.

Knu84

Donald E. Knuth. The TeXbook. Addison Wesley, 1984.

Knu89

D.E. Knuth. The errors of TeX. Software - practice and experience, 19(7):607--685, July 1989.

Lam94

Leslie Lamport. LaTeX, A document preparation system. Addison Wesley, 1994. second edition, updated for LaTeX2e.

...be:

On the left is printed how the input looks like, on the right you will find the result.