Libraries, library(), require(), and packages

• A package is a collection of R code
• A library is a directory of installed packages
  • In many languages, “library” means what “package” means in R
  • See book about setting up user library with new R installation (dir.create(Sys.getenv("R_LIBS_USER"), recursive = TRUE))
• library("pkg", lib.loc = "mylib") loads pkg from mylib into memory
  • NEVER use inside a package
• require("pkg", lib.loc = "mylib") does same but only warns if pkg is missing