Classification is commonplace in thematic cartography. In choropleth mapping, classification is the norm. This was not always so. The first choropleth map (created by Baron Charles Dupin in 1826) was unclassed.
According to Arthur Robinson, in his Early Thematic Mapping in the History of Cartography:
So far as we now know, the [...]
First off, why mess with such a retro format as Arc/Info Export (.e00)?– any code written for this ASCII file type in the last few years has been on how to go from e00 to pretty much anything (especially to the non-topological data format, the shapefile).
Put simply, topological information makes a lot [...]
These election maps are kinda late. Here I’m interested in comparing how we, as a country, voted with our ballots versus how we voted with our dollars. Obama received about 70% of the money donated to the major candidates in 2008, but only 53% of the votes, so I expected a bluer map. [...]