local({ check_package <- function(pkg) { if (!suppressWarnings(suppressMessages(require(pkg, character.only = TRUE)))) { install.packages(pkg, repos = "http://wush978.github.io/R") } } lapply(c("rappdirs", "bitops", "curl"), check_package) utils::install.packages("swirl", repos = "http://wush978.github.io/R") }) library(swirl) library(curl) library(methods) try(uninstall_course("DataScienceAndR"), silent=TRUE) try(uninstall_course("DSC2016-R"), silent=TRUE) swirl::install_course_github("JohnsonHsieh", "DSC2016-R", "course")