Controlling font size on code chunk outputs using Knitr

Yihui/Jeff,

I'm trying to determine where the default CSS file is located as I don't see
this in any of the documentation. I can definitely find a markdwon.css file
in  C:\Program Files\RStudio\resources

I also see an R.css file in that directory.

I also have R.css in C:\Users\jeffjohn\Dropbox\R\Rlibs\rstudio\html which is
where I have all of my packages installed. Would you know how I can
determine what CSS file a given .Rmd file is referencing?

However, I've tried making a simple change to each of them (first backing
them up of course) by changing the h1 to small instead of x-large and saving
the doc, but when I knit the document it does not change anything.

Any guidance you can provide would be extremely helpful. Again, I'm using
R-Studio on Windows.


On Thu, Jan 30, 2014 at 3:54 PM, Jeff Johnson <mrjefftoyou at gmail.com> wrote:

Thanks Yihui and Jeff.

I've retrieved the default CSS file and made a tweak to it (changing a
header 1 size just to test it) and saved it to the same local directory as
my .Rmd file using the name 'mymarkdown.css' for testing.

I've added:
options(rstudio.markdownToHTML =
  function(inputFile, outputFile) {
    require(markdown)
    markdownToHTML(inputFile, outputFile, stylesheet='mymarkdown.css')
  }
)

to the top of my testfile.Rmd file so that my file now looks like:

options(rstudio.markdownToHTML =
  function(inputFile, outputFile) {
    require(markdown)
    markdownToHTML(inputFile, outputFile, stylesheet='mymarkdown.css')
  }
)

Title
========================================================

This is an R Markdown document. Markdown is a simple formatting syntax for
authoring web pages (click the **Help** toolbar button for more details on
using R Markdown).

When you click the **Knit HTML** button a web page will be generated that
includes both content as well as the output of any embedded R code chunks
within the document. You can embed an R code chunk like this:

```{r}
summary(cars)
```

But when I knit it, it just writes the "options" chunk at the top of my
document. Am I supposed to add something else to get the .rmd file to
reference the css?

I'm quite new to programming and R (as if you couldn't tell!), so not sure
what additional steps I need to add.

Thanks much.
Jeff