The company I work for has its own special regions of the US for comparing sales. I'd like to be able to use such R packages as maps, mapdata and maptools but using these custom regions, each of which is defined by sets of zip codes. Is there a package with a function that would allow me to define those custom regions by assigning a set of zip codes to a name for each of the custom regions?
This looked promising at first but it doesn't create custom regions: (how do I map (on a geographical map) data in R just given the US Zipcodes)
Thanks!