title: Changing/adding spatial boundaries/polygon shapefile R
body: <p>I'm dealing with an Afghanistan shapefile which contains all of the provinces.  I ultimately want to plot some data by regional command, which each contain several provinces (this is what I'm talking about: <a href="http://en.wikipedia.org/wiki/File:Afghanistan_ISAF_Sept2008.jpg" rel="nofollow">http://en.wikipedia.org/wiki/File:Afghanistan_ISAF_Sept2008.jpg</a>).  I'm not hugely familiar with handling shapefiles in R, but I haven't found much in the way of tutorials on this issue.  Is it possible to re-draw the polygons or overlay the RC boundaries and plot a choropleth that way? Thanks.</p>