This is an example showing how to document datasets included in the package (in data
folder):
you must specify docType and name; do not forget NULL in the end.
Can include other fields, like citation.
See http://r-pkgs.had.co.nz/data.html for further explanations.
A numeric vector.
This example modified from C. Boettiger's template package https://github.com/cboettig/template.