ABSTRACT
Raster data are fundamentally different from vector data in that they are referenced to a regular grid of rectangular (usually square) cells. The terra package provides a variety of specialized classes and functions for importing, processing, analysing, and visualizing raster datasets. There are numerous other terra functions for raster GIS operations, including aggregating and resampling to different cell sizes, focal statistics, and zonal statistics. Multiple SpatRaster objects can be combined to produce multi-layer raster datasets. Many statistical summary functions have methods for raster objects. In most real applications, more than six years of meteorological data would be used to generate a mean climatology for calculating anomalies. There are also a number of specialized mapping packages that work with terra and sf objects, including rasterVis, tmap, and leaflet.
