The knitr package (Xie 2016) is an alternative tool to Sweave based on a different design with more features. This document is not an introduction, but only serves as a placeholder to guide you to the real manuals, which are available on the package website https://yihui.org/knitr/1, and remember to read the help pages of functions in this package. There is a book (Xie 2015) for this package, but it may not be useful to those who prefer digging out information on the web.
Anyway, here is a code chunk that shows you can compile vignettes with knitr as well using R 3.0.x, which supports non-Sweave vignettes:
##  -0.33060 -0.39099 0.93292 0.59460 -0.57211 0.52964 -2.21362 1.02436 ##  -0.21179 -0.22230 -2.37931 -0.40977 -0.36230 0.04407 -0.49126 -0.93393 ##  1.10141 1.25615 -0.07600 0.92807
|Estimate||Std. Error||t value||Pr(>|t|)|
The fitted regression equation is \(Y=-17.5791+3.9324x\).