```{r setup, include=FALSE} library(knitr) ``` This is an example of Markdown vignettes in R. Before R 3.0.0, only Sweave/PDF vignettes were supported in R. Markdown is gaining popularity over the years due to its simplicity, and R 3.0.0 starts to support package vignettes written in [R Markdown](http://www.rstudio.com/ide/docs/authoring/using_markdown). ## Package vignettes To enable Markdown vignettes in an R package, you need to - add `*.Rmd` files under the `vignettes` directory - add `VignetteBuilder: knitr` to the `DESCRIPTION` file - specify the vignette engine `\VignetteEngine{knitr::knitr}` in the `Rmd` files (inside HTML comments) ## View vignettes And R will load the **knitr** package to build these vignettes to HTML files, and you can see them when you open the HTML help: ```{r eval=FALSE} help(package = 'YourPackage', help_type = 'html') # or see a standalone list of vignettes browseVignettes('YourPackage') ``` ## Examples Below are some code chunks as examples. ```{r hello, results='asis'} if (TRUE) cat('_hello_ **markdown**!', '\n') ``` Normally you do not need any chunk options. ```{r test, collapse=TRUE} 1+1 10:1 rnorm(5)^2 strsplit('hello, markdown vignettes', '') ``` Feel free to draw beautiful plots and write math $P(X>x)=\alpha/2$. ```{r} n=300; set.seed(123) par(mar=c(4,4,.1,.1)) plot(rnorm(n), rnorm(n), pch=21, cex=5*runif(n), col='white', bg='gray') ``` You can use your own CSS file instead of the built-in style in the **markdown** package -- just set the option `markdown.HTML.stylesheet`, e.g. ```{r css, eval=FALSE} options(markdown.HTML.stylesheet = 'path/to/a/custom/style.css') ```