Check the Availability of a Package

Check the Availability of a Package

Usage

needs(x, ask = TRUE)

Arguments

x

A character vector naming the packages to check.

ask

A logical scalar: should the user be asked to select packages before they are downloaded and installed?

Value

Invisibly returns NULL.

Details

needs() is designed for use inside other functions in your own package to check for the availability of a suggested package.

If the required packages are not available and R is running interactively, the user will be asked to install the packages.

See also

Other validation methods: check-attribute, check-data, check-matrix, check-numeric-comparison, check-numeric-trend, check-numeric, check-type, validate()

Author

N. Frerebeau