Are packages installed in any of the libraries?Source:
These functions check that packages are installed with minimal side effects. If installed, the packages will be loaded but not attached.
is_installed()doesn't interact with the user. It simply returns
FALSEdepending on whether the packages are installed.
In interactive sessions,
check_installed()asks the user whether to install missing packages. If the user accepts, the packages are installed with
pak::pkg_install()if available, or
utils::install.packages()otherwise. If the session is non interactive or if the user chooses not to install the packages, the current evaluation is aborted.
You can disable the prompt by setting the
rlib_restart_package_not_found global option to
FALSE. In that
case, missing packages always cause an error.
is_installed(pkg, ..., version = NULL) check_installed(pkg, reason = NULL, ..., version = NULL)
The package names.
These dots must be empty.
Minimum versions for
pkg. If supplied, must be the same length as
NAelements stand for any versions.
Optional string indicating why is
pkgneeded. Appears in error messages (if non-interactive) and user prompts (if interactive).
TRUE if all package names
pkg are installed,
check_installed() either doesn't return or returns
check_installed() signals error conditions of class
rlib_error_package_not_found. The error includes
version fields. They are vectorised and may include several
The error is signalled with a
restart on the stack to allow handlers to install the required
packages. To do so, add a calling handler
rlib_error_package_not_found, install the required packages,
and invoke the restart without arguments. This restarts the check
The condition is not signalled in non-interactive sessions, in the
restarting case, or if the
option is set to