Knitr is an R package that allows us to intermingle R code with LaTeX code. One way to achieve this is internal code chunks. This apporach is demonstrated below.
# r-noweb-file.Rnw
\documentclass{article}
\begin{document}
This is an Rnw file (R noweb). It contains a combination of LateX and R.
<<code-chunk-label>>=
print("This is an R Code Chunk")
x <- seq(1:10)
y <- seq(1:10)
plot(x,y) # Brownian motion
@
\end{document}