zpackages
Listing of Packages
.packages
returns information about package availability.
- Keywords
- data
Usage
.packages(all.available = FALSE, lib.loc = NULL)
Arguments
- all.available
logical; if
TRUE
return a character vector of all available packages inlib.loc
.- lib.loc
a character vector describing the location of R library trees to search through, or
NULL
. The default value ofNULL
corresponds to.libPaths()
.
Details
.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 lib.loc
.
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.
Value
A character vector of package base names, invisible unless
all.available = TRUE
.
Note
.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.
See Also
Examples
library(base)
# NOT RUN {
(.packages()) # maybe just "base"
.packages(all.available = TRUE) # return all available as character vector
require(splines)
(.packages()) # "splines", too
detach("package:splines")
# }