Documenting data objects
If you include a data set in your package you must also provide documentation for it. 
As with package level documentation, you should include a title and description.

With a data set, once again, there is no function object to document. You instead give 
the name of the dataset as a character string, for instance "airquality". 
Additionally there are two tags that you need to use:

@format to describe the format of the data. This is often used with the describe format.
@source to identify where the data came from.
You should then save the package documentation in the R directory with a suitable name 
(in the above case, either airquality.R or data.R).

The weather dataset is available in your workspace. Run print(weather) to view it.