ggmap: Spatial Visualization with ggplot2

improperly specifies the spatial data, e.g. using more than one projection in the same map, but fixing such errors is beyond any framework. The practical advantage of using the grammar is even better. Since the graphics are done in ggplot2 the user can draw from the full range of ggplot2’s capabilities to layer elegant visual content—geoms,

  Using, Projection, Ggmap