透過80 port 來安裝R語言翻轉教室

## init-swirl.R
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)

# Sorry, server.datascienceandr.org is down and will not recover
# install_course_url("http://server.datascienceandr.org/swirl/DataScienceAndR.zip")

download.file("https://github.com/wush978/DataScienceAndR/archive/course.zip", tmp.file <- tempfile(fileext = ".zip"))
unzip(tmp.file, exdir = tempdir())
file.rename(file.path(tempdir(), "DataScienceAndR-course"), file.path(tempdir(), "DataScienceAndR"))
swirl::install_course_directory(file.path(tempdir(), "DataScienceAndR"))