latex

# LaTeX Skill ## 1. Overview LaTeX is a markup language and typesetting system for producing high-quality documents. It excels at structured documents with complex formatting, mathematics, cross-references, and bibliographies. **When to use LaTeX:** - Academic papers, journal submissions - Theses and dissertations - Technical documentation - CVs and résumés - Presentations (Beamer) - Books, reports, letters **Key concepts:** | Concept | Description | |---------|-------------| | **Preamble** | Everything before `\begin{document}` — class, packages, settings | | **Document body** | Content between `\begin{document}` and `\end{document}` | | **Commands** | Start with `\`, e.g. `\textbf{bold}`. Optional args in `[]`, required in `{}` | | **Environments** | `\begin{name}...\end{name}` blocks for scoped formatting | | **Packages** | Extensions loaded with `\usepackage{name}` in the preamble | ## 2. Document Structure ### Document Classes ```latex \documentclass[options]{class} ``` | Class | Use case | |-------|----------| | `article` | Short documents, papers, assignments | | `report` | Longer documents with chapters | | `book` | Books (front/back matter, chapters) | | `beamer` | Presentations/slides | | `letter` | Formal letters | | `memoir` | Flexible — replaces article/report/book | ### Common Class Options ```latex \documentclass[12pt,a4paper,twocolumn,draft]{article} ``` | Option | Values | |--------|--------| | Font size | `10pt`, `11pt`, `12pt` | | Paper | `a4paper`, `letterpaper`, `a5paper` | | Columns | `onecolumn`, `twocolumn` | | Sides | `oneside`, `twoside` | | Draft | `draft` (shows overfull boxes, skips images) | ### Minimal Document ```latex \documentclass[12pt,a4paper]{article} % === PREAMBLE === \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc} \usepackage{amsmath, amssymb} \usepackage{graphicx} \usepackage{hyperref} \title{My Document} \author{Author Name} \date{\today} % === BODY === \begin{document} \maketitle \tableofcontents \section{Introduction} Content here. \end{document} ``` ## 3. Text Formatting ### Style Commands | Command | Result | |---------|--------| | `\textbf{text}` | **bold** | | `\textit{text}` | *italic* | | `\underline{text}` | underlined | | `\emph{text}` | emphasis (italic, or upright if already italic) | | `\texttt{text}` | `monospace` | | `\textsc{text}` | SMALL CAPS | | `\textsf{text}` | sans-serif | ### Font Sizes Smallest to largest: ``` \tiny \scriptsize \footnotesize \small \normalsize \large \Large \LARGE \huge \Huge ``` Use as: `{\large This text is large.}` or as environment. ### Font Families | Command | Declaration | Family | |---------|-------------|--------| | `\textrm{}` | `\rmfamily` | Serif (Roman) | | `\textsf{}` | `\sffamily` | Sans-serif | | `\texttt{}` | `\ttfamily` | Monospace | ### Alignment ```latex \begin{center} Centered text. \end{center} \begin{flushleft} Left-aligned. \end{flushleft} \begin{flushright} Right-aligned. \end{flushright} ``` Or inline: `\centering`, `\raggedright`, `\raggedleft` ### Spacing ```latex \vspace{1cm} % vertical space \hspace{2em} % horizontal space \vfill % stretch vertical \hfill % stretch horizontal \\[0.5cm] % line break with extra space \setlength{\parskip}{0.5em} % paragraph spacing \setlength{\parindent}{0pt} % remove paragraph indent \noindent % suppress indent for one paragraph ``` Line spacing (requires `setspace` package): ```latex \usepackage{setspace} \onehalfspacing % or \doublespacing, \singlespacing ``` ### Special Characters These characters must be escaped: | Character | LaTeX | Character | LaTeX | |-----------|-------|-----------|-------| | `%` | `\%` | `$` | `\$` | | `&` | `\&` | `#` | `\#` | | `_` | `\_` | `{` | `\{` | | `}` | `\}` | `~` | `\textasciitilde` | | `^` | `\textasciicircum` | `\` | `\textbackslash` | ## 4. Document Organization ### Sectioning ```latex \part{Part Title} % only in report/book \chapter{Chapter Title} % only in report/book \section{Section} \subsection{Subsection} \subsubsection{Subsubsection} \paragraph{Paragraph} \paragraphsub{Subparagraph} ``` Starred versions (`\section*{}`) suppress numbering and TOC entry. ### Table of Contents ```latex \tableofcontents % requires two compilations \listoffigures \listoftables ``` ### Lists ```latex % Bulleted \begin{itemize} \item First item \item Second item \end{itemize} % Numbered \begin{enumerate} \item First \item Second \end{enumerate} % Labeled \begin{description} \item[Term] Definition here. \end{description} ``` Customize with `enumitem` package: ```latex \usepackage{enumitem} \begin{enumerate}[label=(\alph*), start=1] ``` ### Cross-References ```latex \section{Methods}\label{sec:methods} See Section~\ref{sec:methods} on page~\pageref{sec:methods}. ``` With `hyperref`, use `\autoref{sec:methods}` for automatic "Section 2" text. **Rule:** Always place `\label` *after* `\caption` (in floats) or after the sectioning command. ### Footnotes ```latex This has a footnote.\footnote{Footnote text here.} ``` ## 5. Mathematics ### Inline vs Display ```latex Inline: $E = mc^2$ or \(E = mc^2\) Display: \[ E = mc^2 \] % Numbered equation: \begin{equation}\label{eq:einstein} E = mc^2 \end{equation} ``` ### Essential Packages ```latex \usepackage{amsmath} % align, cases, matrices, etc. \usepackage{amssymb} % extra symbols (ℝ, ℤ, etc.) \usepackage{mathtools} % extends amsmath (dcases, coloneqq, etc.) ``` ### Common Constructs ```latex % Fractions \frac{a}{b} \dfrac{a}{b} (display-size) % Roots \sqrt{x} \sqrt[3]{x} % Sub/superscripts x_{i} x^{2} x_{i}^{2} a_{i,j} % Sums, products, integrals \sum_{i=1}^{n} x_i \prod_{i=1}^{n} x_i \int_{0}^{\infty} f(x)\,dx \lim_{x \to \infty} f(x) % Brackets (auto-sized) \left( \frac{a}{b} \right) \left[ ... \right] \left\{ ... \right\} ``` ### Matrices ```latex \begin{pmatrix} a & b \\ c & d \end{pmatrix} % (a b; c d) \begin{bmatrix} a & b \\ c & d \end{bmatrix} % [a b; c d] \begin{vmatrix} a & b \\ c & d \end{vmatrix} % |a b; c d| (determinant) \begin{Bmatrix} a & b \\ c & d \end{Bmatrix} % {a b; c d} ``` ### Aligned Equations ```latex \begin{align} f(x) &= x^2 + 2x + 1 \label{eq:f} \\ g(x) &= x^3 - 1 \label{eq:g} \end{align} % No numbering: \begin{align*} a &= b + c \\ d &= e + f \end{align*} ``` ### Cases ```latex f(x) = \begin{cases} x^2 & \text{if } x \geq 0 \\ -x^2 & \text{if } x < 0 \end{cases} ``` ### Greek Letters | Lower | Command | Upper | Command | |-------|---------|-------|---------| | α | `\alpha` | Α | `A` | | β | `\beta` | Β | `B` | | γ | `\gamma` | Γ | `\Gamma` | | δ | `\delta` | Δ | `\Delta` | | ε | `\epsilon`, `\varepsilon` | Ε | `E` | | θ | `\theta` | Θ | `\Theta` | | λ | `\lambda` | Λ | `\Lambda` | | μ | `\mu` | — | — | | π | `\pi` | Π | `\Pi` | | σ | `\sigma` | Σ | `\Sigma` | | φ | `\phi`, `\varphi` | Φ | `\Phi` | | ω | `\omega` | Ω | `\Omega` | ### Common Math Symbols | Symbol | Command | Symbol | Command | |--------|---------|--------|---------| | ≤ | `\leq` | ≥ | `\geq` | | ≠ | `\neq` | ≈ | `\approx` | | ± | `\pm` | × | `\times` | | ÷ | `\div` | · | `\cdot` | | ∈ | `\in` | ∉ | `\notin` |