Metadata for data updating frequency, last version

[trashbirdecology]

Please provide metadata or information in the README (or elsewhere) which provides information on the frequency (preferably the times) at which the boundaries are updated.

Would also be really cool to have historical boundaries available (might increase probability of people using this package for time series visualizations of political boundary shifts, eg gerrymandering)

[pdil]

@trashbirdecology I agree with adding the times at which the boundary data sets were updated, I can go back through the repo history to add those in.

However, for your second point, it would be difficult to include the historical boundaries themselves because the files that are used now already put the package over CRAN's recommended 5 MB limit so adding more and more data sets over time would greatly increase the package's size.

[trashbirdecology]

Yep, figured that was a big ask.

Perhaps a file with links for simple importation of previous boundaries?

[pdil]

@trashbirdecology yeah I have thought about making a script that automatically downloads the shapefiles and creates the data frame. If I can get it to work I can add the year (I think the state/county shape files are only updated once per year) as a parameter in us_map which would then download and create the data frame. It would take longer than usual but would still be better than nothing. I'll keep this in mind for a future update.