install.packages( lib = lib <- .libPaths()[1], pkgs = as.data.frame(installed.packages(lib), stringsAsFactors=FALSE)$Package, type = ‘source’ )   # store_packages.R # # stores a list of your currently installed packages tmp = installed.packages() installedpackages = as.vector(tmp[is.na(tmp[,”Priority”]), 1]) save(installedpackages, file=”~/Desktop/installed_packages.rda”) # restore_packages.R # # installs each package from the stored list of packages load(“~/Desktop/installed_packages.rda”) for (count in 1:length(installedpackages)) install.packages(installedpackages[count])