Below is the error I am getting:
Quitting from lines 46-48 (lesson3_student.rmd) Error in contrib.url(repos, "source") : trying to use CRAN without setting a mirror Calls: <Anonymous> ... withVisible -> eval -> eval -> install.packages -> contrib.url In addition: Warning message: In in_dir(opts_knit$get("root.dir") %n% input_dir(), evaluate::evaluate(code, : You changed the working directory to /Users/Madiyar/Desktop/Facebook Data (probably via setwd()). It will be restored to /Users/Madiyar/Downloads. See the Note section in ?knitr::knit Execution halted
Thanks for help