This help topic is for R version 2.9.0. For the current version of R, try https://stat.ethz.ch/R-manual/R-patched/library/base/html/ns-load.html
ns-load {base}R Documentation

Loading and Unloading Name Spaces

Description

Functions to load and unload namespaces.

Usage

attachNamespace(ns, pos = 2, dataPath = NULL)
loadNamespace(package, lib.loc = NULL,
              keep.source = getOption("keep.source.pkgs"),
              partial = FALSE, declarativeOnly = FALSE)
loadedNamespaces()
unloadNamespace(ns)

Arguments

ns

string or namespace object.

pos

integer specifying position to attach.

dataPath

path to directory containing a database of datasets to be lazy-loaded into the attached environment.

package

string naming the package/name space to load.

lib.loc

character vector specifying library search path.

keep.source

logical specifying whether to retain source. This applies only to the specified name space, and not to other name spaces which might be loaded to satisfy imports.

For more details see this argument to library.

partial

logical; if true, stop just after loading code.

declarativeOnly

logical; disables .Import, etc, if true.

Details

The functions loadNamespace and attachNamespace are usually called implicitly when library is used to load a name space and any imports needed. However it may be useful to call these functions directly at times.

loadNamespace loads the specified name space and registers it in an internal data base. A request to load a name space when one of that name is already loaded has no effect. The arguments have the same meaning as the corresponding arguments to library, whose help page explains the details of how a particular installed package comes to be chosen. After loading, loadNamespace looks for a hook function named .onLoad as an internal variable in the name space (it should not be exported). This function is called with the same arguments as .First.lib. Partial loading is used to support installation with the --save and --lazy options.

loadNamespace does not attach the name space it loads to the search path. attachNamespace can be used to attach a frame containing the exported values of a name space to the search path. The hook function .onAttach is run after the name space exports are attached.

loadedNamespaces returns a character vector of the names of the loaded name spaces.

unloadNamespace can be used to attempt to force a name space to be unloaded. If the namespace is attached, it is first detached, thereby running a .Last.lib function in the namespace if one is exported. Then an error is signaled if the name space is imported by other loaded name spaces, and the namespace is not unloaded. If defined, a hook function .onUnload is run before removing the name space from the internal registry.

Value

attachNamespace returns invisibly the environment it adds to the search path.

loadNamespace returns the namespace environment, either one already loaded or the one the function causes to be loaded.

loadedNamespaces returns a character vector.

unloadNamespace returns NULL, invisibly.

Author(s)

Luke Tierney


[Package base version 2.9.0 ]