R Language R in LaTeX with knitr R in Latex with Knitr and Code Externalization
Example
Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is external code chunks. External code chunks allow us to develop/test R Scripts in an R development environment and then include the results in a report. It is a powerful organizational technique. This approach is demonstrated below.
# r-noweb-file.Rnw
\documentclass{article}
<<echo=FALSE,cache=FALSE>>=
knitr::opts_chunk$set(echo=FALSE, cache=TRUE)
knitr::read_chunk('r-file.R')
@
\begin{document}
This is an Rnw file (R noweb). It contains a combination of LateX and R.
One we have called the read\_chunk command above we can reference sections of code in the r-file.R script.
<<Chunk1>>=
@
\end{document}
When using this approach we keep our code in a separate R file as shown below.
## r-file.R
## note the specific comment style of a single pound sign followed by four dashes
# ---- Chunk1 ----
print("This is R Code in an external file")
x <- seq(1:10)
y <- rev(seq(1:10))
plot(x,y)
