ABSTRACT
This chapter provides explanations of the fundamental geographic data models: vector and raster. It introduces the theory behind each data model and the disciplines in which they predominate, before demonstrating their implementation in R. Take care when using the word ‘vector’ as it can have two meanings in this book: geographic vector data and the vector class in R. The geographic vector data model is based on points located within a coordinate reference system. The geographic raster data model usually consists of a raster header and a matrix representing equally spaced cells. Raster maps usually represent continuous phenomena such as elevation, temperature, population density or spectral data. The raster data model divides the surface up into cells of constant size. Raster datasets are the basis of background images used in web-mapping and have been a vital source of geographic data since the origins of aerial photography and satellite-based remote sensing devices.
