# [Courses] [LaTeX] Course 1 - Introduction

Isabelle Hurbain isabelle.hurbain at free.fr
Wed Jul 17 23:44:52 EST 2002

Hello everyone,

I suggested three days ago on the IRC channel to run LaTeX courses, and as
I had positive feedback about it, here is the first course ;)
This is text only ; you can have the PDF/TeX/DVI version on my website :
<http://www.isabelle-hurbain.com/repository/latex/courses/>.
I hope you'll enjoy it ! Please do not hesitate to contact me for any
question - or mistake (I've tried to make this as error proof as I could,
but English is not my mother tongue...)

Isa - Balise

LaTeX course 1 : Introduction

Contents

1. But what is LaTeX anyway ?
2. What do I need to make LaTeX ?
3. LaTeX Hello World

1. But what is LaTeX anyway ?

LaTeX is a document preparation system. It allows you to create
professional-looking documents without pain. The main idea of LaTeX is that
the author of the document concentrates on the content and not the form of
the document. To achieve this, LaTeX provides a set of macros and
predefined styles.

Let's take a basic example. On a "standard" word-processing tool, to make a
section title, most people use form-modifying commands. For example, they
put it in Bold, Underlined, Size 16. With LaTeX, the form of your document
is independant of its content : your section title will be in a \section
command and you let LaTeX manage how it will be printed and diplayed.

You may ask : "What's the big point ?" Well, there are indeed at least
three big points. The first is obviously that you don't have to remember
what "style" you used for your previous sections, subsections, chapters and
so on. The second is that when you decide that your section title font is
too big, you don't have to change it in the whole document, you can do it
with a single modification. The third is that, as the document is marked
with sections, subsections and so on, it is much easier to do tables of
contents - in fact, it can be done automagically.

The last point I'd like to underline is that LaTeX is really fantastic to
typeset mathematical formulaes. You will soon see that once used, you
cannot do without LaTeX for scientific publishing ;-)

I hope that this very short introduction has given you the envy to
continue, so let's go !

2. What do I need to make LaTeX ?

LaTeX is not, like most word-processors, WYSIWYG (What You See Is What You
Get) (or, more frequently, WYSIMOLWYG, What You See Is More Or Less What
You Get). You first write your LaTeX source code, then you compile it into
a .dvi file, which you can transform in .ps or .pdf. There are also means
to convert into HTML for example.

So what you need are basically :
- a text editor - Emacs, Vi, TextPad, UltraEdit or whatever you like
- a LaTeX distribution. You can find teTeX under Linux Debian, and there
is a TeX/LaTeX distribution bundled with almost all Linux distribution.
Under Windows, if you use Cygwin there is also a teTeX ; you can also find
MiKTeX and TeX Live (I'm sorry for Mac users, I don't use Mac so you'll
have to find a Mac distro yourself :P )
- a .ps or a .pdf viewer (or both). There are numerous - the most famous
are gv / Ghostview for .ps and Adobe Acrobat Reader for .pdf.
\end{itemize}

All these things can be installed very easily - just do it the way you
install any other program.

Once all is installed, let's write our first LaTeX document.

3. LaTeX Hello World
3.1 The document

We will look at a very simple document :

\documentclass[a4paper, 11pt]{article}
\title{My first \LaTeX{} Document}
\author{Isabelle HURBAIN}
\begin{document}
\maketitle
Hello, world !
\end{document}

You can copy and past it into, for example, a new text file named
"helloworld.tex".

3.2 Compilation
Save it, and compile it. To compile the file, just cd to the directory you
saved it into and type

latex helloworld.tex

in a console tool (or a command in Windows).

You should see some lines displaying, and three new files are created.

- The .dvi file is the output of the compilation - what you can view and print
- The .aux file is an auxilliary file, which contains things like section
numbers and figures numbers, so that it is possible to create a table of
contents or a table of figures
- The .log file is the file that logs all LaTeX information - LaTeX
compilation messages and errors.

3.3 Visualization
Your LaTeX distribution probably provides a way to visualize .dvi files -
in teTeX there is xdvi, in MiKTeX there is YAP...

If you find a .dvi viewer, you can directly view the helloworld.dvi file.
If not, you can use

dvips helloworld.dvi

to get a ps file, or

dvipdfm helloworld.dvi

to get a pdf file. (dvipdfm can be slightly different, you may also find
dvipdf or others).

Nice isn't it ?

3.4 Explanations
Let's look a bit more at the code. As you can see, all the commands begin
with a \ ; \ is a special character in LaTeX that can be typed with
$\backslash$. The other special characters ({, }, $, %, # and _) can be obtained with \{, \}, \$, \%, \# and \_. A \\ breaks the line (but you
should not use this much as we'll see later).

The first line,

\documentclass[a4paper, 11pt]{article}

is very important. It tells LaTeX several things. \documentclass{article}
tells it to follow an article layout. There are other layouts, such as
report, book, letter... which we will discover in this course.  The a4paper
and 11pt in the square brackets are general parameters of the document. I
will talk about it a bit further in these courses. It tells LaTeX that the
result will be printed onto A4 paper, with a text character size of 11
points. Of course, if you use letter paper, feel free to replace a4paper
with letterpaper.

\title{My first \LaTeX{} Document}

defines the title of the document, with a lovely LaTeX symbol.

\author{Isabelle HURBAIN}

defines the author of the document.

\begin{document}

is the signal for LaTeX that the real document begins. The lines before
this line are called the preamble of the document.

\maketitle

is a command to create a title from the information in the preamble
(typically \title and \author, eventually \date).

After that, you can compose the document (here just Hello, world !''),
and finish it by

\end{document}.

It is true that it seems a bit complicated for just that. However, look how
simple it was to create the title...

4. In the next course
In the next course, we will learn how to create a real-world document, with
titles and sections, and I will explain more deeply the form-content