Blog with Knitr and Jekyll

Posted on April 08, 2015

Step

Open the R Console and process the source file:

KnitPost <- function(input, base.url = "/") {
  require(knitr)
  opts_knit$set(base.url = base.url)
  fig.path <- paste0("figs/", sub(".Rmd$", "", basename(input)), "/")
  opts_chunk$set(fig.path = fig.path)
  opts_chunk$set(fig.cap = "center")
  render_jekyll()
  knit(input, envir = parent.frame())
}
KnitPost("2012-07-03-knitr-jekyll.Rmd")

###Implement MathJax in Jekyll. When using Jekyll to create the blog, sometimes we need to type mathematical formula in the articles. MathJax is a powerful tool to display beautiful formulas on the website. To load the MathJax javascript, we can add the following lines in the post.html, which is located in the folder _layouts.

A Couple of Examples

If you are familiar with LaTex, the behavior of MathJax is very similar with LaTex, but not all the same.

To display in-line math, \\( ...\\) can achieve this goal:

If one want to display \( sin(x)\), just use the code \\(sin(x)\\).

\\[...\\] and $$ .. $$ can be used for displaying equations, such as:

\\[ \mathbf{X} = \mathbf{Z} \mathbf{P^\mathsf{T}} \\]

\[ \mathbf{X} = \mathbf{Z} \mathbf{P^\mathsf{T}} \]

Or, one can also use LaTex delimiters Double Dollar signs

$$ \mathbf{X_{n,p}} = \mathbf{A_{n,k}} \mathbf{B_{k,p}}$$

which we can get formula like:

However, the LaTex delimiter $ .. $ is not defined in this case, so one can not use code like $ \mathbf{X_{t}} $ to get formula \(\mathbf{X_{t}}\).