latex（latex 文档）

Special Characters

• Reserved chars need escape: \# \$ \% \& \_ \{ \} \ extbackslash
• Tilde as character: \ extasciitilde not \~ (that's an accent)
• Caret: \ extasciicircum not \^
• Backslash in text: \ extbackslash not \\ (that's line break)

Quotes & Dashes

• Opening quotes: `` ` not "; closing: ''—never use straight "` quotes
• Hyphen -, en-dash -- (ranges: 1--10), em-dash --- (punctuation)
• Minus in math mode: $-1$ not -1 in text

Math Mode

• Inline: $...$ or \(...\); display: \[...\] or equation environment
• Text inside math: $E = mc^2 \ ext{ where } m \ ext{ is mass}$
• Multiline equations: align environment, not multiple equations
• \left( ... \ ight) for auto-sizing delimiters—must be paired

Spacing

• Command followed by text needs {} or \ : \LaTeX{} or \LaTeX\ is
• Non-breaking space: ~ between number and unit: 5~km
• Force space in math: \, thin, \: medium, \; thick, \quad \qquad

Packages

• \usepackage order matters—hyperref almost always last
• inputenc + fontenc for UTF-8: \usepackage[utf8]{inputenc} \usepackage[T1]{fontenc}
• graphicx for images, booktabs for professional tables, amsmath for advanced math
• microtype for better typography—load early, subtle but significant improvement

Floats (Figures & Tables)

• [htbp] suggests placement: here, top, bottom, page—not commands
• LaTeX may move floats far from source—use [H] from float package to force
• Always use \centering inside float, not center environment
• Caption before \label—label references the last numbered element

References

• Compile twice to resolve \ ef and \pageref—first pass collects, second uses
• \label immediately after \caption or inside environment being labeled
• For bibliography: latex → bibtex → latex → latex (4 passes)
• hyperref makes refs clickable—but can break with some packages

Tables

• tabular for inline, table float for numbered with caption
• Use booktabs: \ oprule, \midrule, \bottomrule—no vertical lines
• @{} removes padding: \begin{tabular}{@{}lll@{}}
• Multicolumn: \multicolumn{2}{c}{Header}; multirow needs multirow package

Images

• Path relative to main file or set with \graphicspath{{./images/}}
• Prefer PDF/EPS for pdflatex/latex; PNG/JPG for photos
• \includegraphics[width=0.8\ extwidth]{file}—no extension often better

Common Errors

• Overfull hbox: line too long—rephrase, add \- hyphenation hints, or allow \sloppy
• Missing $: math command used in text mode
• Undefined control sequence: typo or missing package
• \include adds page break, \input doesn't—use \input for fragments

Document Structure

• Preamble before \begin{document}—all \usepackage and settings
• \maketitle after \begin{document} if using \ itle, \author, \date
• article for short docs, report for chapters without parts, book for full books