I'm trying to save my R output in pdf format, but cannot find a knitr package in my list of packages. Could you please let me know if there is any other way to perform this operation?
install.packages('knitr', repos='http://cran.rstudio.org') or
devtools::install_github("yihui/knitr"), as suggested above. If both do not work, can you please let us know of the error you get. Also upgrading R might be a good solution.