isPackageLoaded: Checks if a package is loaded or not
Description
Checks if a package is loaded or not.
Note that, contrary to require(),
this function does not load the package if not loaded.
Usage
# S3 method for default
isPackageLoaded(package, version=NULL, ...)
Arguments
version
A character string specifying the version to test for.
If NULL, any version is tested for.