R: Attach or load packages, and automatically install missing...

pkg_attach {xfun}

R Documentation

Attach or load packages, and automatically install missing packages if requested

Description

pkg_attach() is a vectorized version of library() over the package argument to attach multiple packages in a single function call. pkg_load() is a vectorized version of requireNamespace() to load packages (without attaching them). The functions pkg_attach2() and pkg_load2() are wrappers of pkg_attach(install = TRUE) and pkg_load(install = TRUE), respectively. loadable() is an abbreviation of requireNamespace(quietly = TRUE).

Usage

pkg_attach(..., install = FALSE)

pkg_load(..., error = TRUE, install = FALSE)

loadable(pkg, strict = TRUE)

pkg_attach2(...)

pkg_load2(...)

Arguments

`...`	Package names (character vectors, and must always be quoted).
`install`	Whether to automatically install packages that are not available using `install.packages()`. You are recommended to set a CRAN mirror in the global option `repos` via `options()` if you want to automatically install packages.
`error`	Whether to signal an error when certain packages cannot be loaded.
`pkg`	A single package name.
`strict`	If `TRUE`, use `requireNamespace()` to test if a package is loadable; otherwise only check if the package is in `.packages(TRUE)` (this does not really load the package, so it is less rigorous but on the other hand, it can keep the current R session clean).

Details

These are convenience functions that aim to solve these common problems: (1) We often need to attach or load multiple packages, and it is tedious to type several library() calls; (2) We are likely to want to install the packages when attaching/loading them but they have not been installed.

Value

pkg_attach() returns NULL invisibly. pkg_load() returns a logical vector, indicating whether the packages can be loaded.

Examples

library(xfun)
pkg_attach("stats", "graphics")
# pkg_attach2('servr') # automatically install servr if it is not installed

(pkg_load("stats", "graphics"))

[Package xfun version 0.1 Index]