knit_hooks

A hook is a function of a pre-defined form (arguments)
  that takes values of arguments and returns desired
  output. The object <code>knit_hooks</code> is used to access or
  set hooks in this package.

datasets

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 or inspired by Sweave, cacheSweave,
        pgfSweave, brew and decumar.

Yihui Xie

knitr

A general-purpose package for dynamic report generation in R

knit_hooks function

List of 4
 $ get    :function (name, default = FALSE)  
 $ set    :function (...)  
 $ merge  :function (values)  
 $ restore:function ()

knit_hooks: Hooks for R code chunks, inline R code and output

Description

Usage

Arguments

format

References

Examples