Creating different maps based on different map projection types
If you go back to Figure 6.4 (recipe Crafting choropleth maps using ggplot2, How to do it... section), several aspects from the map feel right, others might feel funny. This happened because the scale used was unusual; to be honest, scales were free and ruled by figure aspect ratio along with data. Ratio is related to the projection type--it's a source of distortion--and there are ways to set it stone still, one (not the best) already introduced at the end of the previous recipe .
This recipe's intention is to teach you how one or another projection type can be selected. Speaking about ggplot2
, it has a whole function dedicated to this purpose. Projection types can widely vary and we are again taking off from the results obtained by the Crafting choropleth maps using ggplot2 recipe.
Although fully understanding maps, scales, projections, and symbolization may seem complicated (yet very important), picking (and not choosing) one...