gistfile1.txt

# to add latex equations to a Rmd file, enclose the equations using the $ $ syntax
# and run knit_equation on the Rmd file instead of knit
knit_equation = function(rmd, md) {
  require('knitr')
  require('RCurl')
  gist_url = 'https://gist.github.com/roryk/4476421/raw/d08080c206b5663e0451a5ef6c56635a0c6f0f17/gistfile1'
  #gist_url = 'https://gist.github.com/raw/4476421/d08080c206b5663e0451a5ef6c56635a0c6f0f17/gistfile1'
  tmp = tempfile()
  knit(rmd, tmp)
  f = file(md, "w")
  header = getURL(gist_url, ssl.verifypeer = FALSE)
  writeLines(header, f)
  writeLines(readLines(tmp), f)
  close(f)
}