# knitr v0.9

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## A general-purpose package for dynamic report generation in R

This package provides a general-purpose tool for dynamic report generation in R, which can be used to deal with any type of (plain text) files, including Sweave, HTML, Markdown and reStructuredText. The patterns of code chunks and inline R expressions can be customized. R code is evaluated as if it were copied and pasted in an R terminal thanks to the evaluate package (e.g. we do not need to explicitly print() plots from ggplot2 or lattice). R code can be reformatted by the formatR package so that long lines are automatically wrapped, with indent and spaces being added, and comments being preserved. A simple caching mechanism is provided to cache results from computations for the first time and the computations will be skipped the next time. Almost all common graphics devices, including those in base R and add-on packages like Cairo, cairoDevice and tikzDevice, are built-in with this package and it is straightforward to switch between devices without writing any special functions. The width and height as well as alignment of plots in the output document can be specified in chunk options (the size of plots for graphics devices is still supported as usual). Multiple plots can be recorded in a single code chunk, and it is also allowed to rearrange plots to the end of a chunk or just keep the last plot. Warnings, messages and errors are written in the output document by default (can be turned off). Currently LaTeX, HTML, Markdown and reST are supported, and other output formats can be supported by hook functions. The large collection of hooks in this package makes it possible for the user to control almost everything in the R code input and output. Hooks can be used either to format the output or to run a specified R code fragment before or after a code chunk. The language in code chunks is not restricted to R only (there is simple support to Python and Awk, etc). Many features are borrowed from or inspired by Sweave, cacheSweave, pgfSweave, brew and decumar.

## Functions in knitr

 Name Description knit_patterns Patterns to match and extract R code in a document image_uri Encode an image file to a data URI set_header Set the header information stitch Automatically create a report based on an R script and a template hook_movecode A document hook function to move code out of floating environments knit_rd Knit package documentation opts_template Template for creating reusable chunk options eclipse_theme Download and convert a theme from eclipsecolorthemes.org to CSS knit_child Knit a child document all_patterns All built-in patterns hook_plot_tex Default plot hooks for different output formats imgur_upload Upload a image to imgur.com hook_rgl Built-in chunk hooks to extend knitr knit2pdf Convert Rnw or Rrst files to PDF using knit() and texi2pdf() or rst2pdf() knit_engines Engines of other languages opts_knit Options for the knitr package set_parent Specify the parent document of child documents knit Knit a document knitr-package A general-purpose tool for dynamic report generation in R dep_prev Make later chunks depend on previous chunks rst2pdf A wrapper for rst2pdf knit2html Convert markdown to HTML using knit() and markdownToHTML() read_rforge Read source code from R-Forge pat_rnw Set regular expressions to read input documents write_bib Generate BibTeX bibliography databases for R packages set_alias Set aliases for chunk options fig_path Path for figure files knit_theme Syntax highlighting themes read_chunk Read chunks from an external script knit_hooks Hooks for R code chunks, inline R code and output knit_env The environment in which a code chunk is evaluated render_latex Set output hooks for different output formats run_chunk Run the code in a specified chunk rand_seed An unevaluated expression to return .Random.seed if exists dep_auto Build automatic dependencies among chunks opts_chunk Default and current chunk options hook_ffmpeg_html Hooks to create animations in HTML output spin Spin goat's hair into wool No Results!