Listing of Packages
.packages returns information about package availability.
.packages(all.available = FALSE, lib.loc = NULL)
- logical; if
TRUEreturn a character vector of all available packages in
- a character vector describing the location of R
library trees to search through, or
NULL. The default value of
.packages() returns the names of the currently
attached packages invisibly whereas
.packages(all.available = TRUE) gives (visibly) all
packages available in the library location path
For a package to be regarded as being available it must have valid
metadata (and hence be an installed package). However, this will
report a package as available if the metadata does not match the
directory name: use
find.package to confirm that the
metadata match or
installed.packages for a much slower
but more comprehensive check of available packages.
A character vector of package base names, invisible unless
all.available = TRUE.
.packages(all.available = TRUE) is not a way to find out if a
small number of packages are available for use: not only is it
expensive when thousands of packages are installed, it is an
incomplete test. See the help for
find.package for why
require should be used.
(.packages()) # maybe just "base" .packages(all.available = TRUE) # return all available as character vector require(splines) (.packages()) # "splines", too detach("package:splines")