A quick start

I demonstrate LaTeX on an example document. Let us start with the plain text version of an article I wrote on fractals, The importance of beings fractal. In practise, you create a document in LaTeX from the outset.

Document classes

Saving part of the article as text looks like Src/fractals00.tex, with all formatting, mathematics and figures lost. We restore and improve the formatting and the mathematics to produce a superb final document (pdf,120K).

Around the document text that you wish to typeset, you need

\documentclass[12pt]{article}
\begin{document}
...
\end{document}

as in Src/fractals01.tex which we now typeset.

Use for processing (see Comparison of TeX editors)

Easily over the internet
Overleaf (free) which appears a very good place to get started (however, I have not investigated their reliability nor data management).

Windows PCs
editors TeXnicCenter (free) or TeXworks (free), and the LaTeX processor mikTeX (free)

Unix
editors Emacs+AuCTeX (free) and the LaTeX processor tetex (free)

Macs
perhaps TeXShop or TeXworks

Restore the paragraph structure  by introducing a blank line to indicate to LaTeX where one paragraph ends and another begins, as in Src/fractals02.tex. All other line breaks in the source are treated as simply blank characters.

Other document classes  are report (for long articles such as a dissertation), book, and letter.

Other options  are the smaller sizes of fonts: [11pt]; or none at all which gives 10pt. Additional options may be provided, such as a4paper or twocolumn, within the [] and separated by commas.

For most purposes I recommend one of the following:

• \documentclass[12pt,a4paper]{article} for many purposes;
• save paper with \documentclass[a4paper,twocolumn]{article} for an easily readable newspaper type format;
• e-book friendly typesetting, and to draft onscreen easily, and save paper by printing two pages per sheet of A4 paper, use \documentclass[12pt,a5paper]{article}, followed by \usepackage[a5paper,margin=6mm]{geometry}. This gives the same line width as the default for a4paper.
As you go through this, try some of these alternatives to see how LaTeX easily reformats the document to changing needs.

Sectioning

The sections and subsections need to be typeset clearly. These are indicated by the

\section{section-name}

and

\subsection{subsection-name}

commands as in Src/fractals03.tex.

Note that LaTeX automatically numbers the sections and subsections, so do not number them yourself.

Observe the use of the backslash or 'slosh' to introduce a command in LaTeX, followed by an argument in enclosed in braces.

Other sectioning commands are \chapter, \subsubsection, and \paragraph.

Titles

There are also special commands for a title. The format is
\title{title-text}
\maketitle

as in Src/fractals04.tex.

Observe that LaTeX uses today's date. Override with the \date{any-date} command anywhere before the \maketitle. (Good practice is to use \date, comment on the version, and keep the version history as comments.)

Multiple authors should be separated by \and within \author{...\and...}

Addresses and thanks by author(s) usually appear as footnotes by using \thanks{...} immediately after the author(s).

Not only are the slosh, '\', and the braces, '{' and '}', special characters to LaTeX, so is the percent sign '%'. It causes LaTeX to ignore the rest of the line, so we can comment the document if needed. Other special characters are:

• the dollar, '\$';
• the ampersand, '&';
• the underscore, '_'; and
• the hash, '#'.

To actually get any of these last seven characters (but not "\") to appear in the final typeset document, just precede them by a slosh (as now seen in the name of the department).

The double slosh '\\' is reserved to force a line break in certain circumstances---use it sparingly.

Font styles

LaTeX typesets most of a document in (Computer Modern) roman font. Section and subsection titles are typeset in bold face. LaTeX has other font styles available. These are invoked by the following commands with argument the text to be affected:

• \emph{...} invokes italic for emphasis (and sometimes addresses);
• \texttt{...} typesets its argument in a fixed width teletype-like font, useful for code fragments and the like;
• whereas if needed, \textbf{...} and \textnormal{...} typesets bold face and the normal roman respectively.

These font styles are mainly used in the following way:

\emph{this is in italic}, but this is not.
as in Src/fractals05.tex.

Note: these style changes are cumulative so you can have italic bold by \emph{\textbf{...}} (provided the fonts are actually available on your system!).

LaTeX's default is to number each page, centered in the footing. A more descriptive running page header is obtained by including the command

\pagestyle{headings}
in the preamble (that bit before the \begin{document} in which the title and author may also go), as in Src/fractals06.tex. To see the headings we need a wider margin, at least 13mm.