Raster data can be continuous (e.g., elevation or rainfall) or discrete (e.g., land use or vegetation type). The spatial resolution of raster data is determined by the size of the cells it is comprised of (e.g., one cell in a raster map can represent a 10x10m area on the surface of the Earth). Raster data represents the world as a continuous surface divided into a regular grid of cells (pixels), where each cell contains a value corresponding to the measured value for the area the cell represents. Vector data is most useful to represent spatial phenomena that has discrete boundaries, like county borders or streets. Vector data is stored as a list of coordinates that define vertices (points), and a set of rules that determine if and how the vertices are joined into lines or polygons. Vector data represents the world with points, lines, and polygons. Although it is true that vector and raster data are both ways of representing spatial data, and most data can be represented as either vector or raster, the data types are very different, and each one can shine brighter than the other for different use cases and data sets. This verbal jousting escalated to fist fights in the streets, elaborate traps staged in musty academic buildings, and eventually the cold-war-style standoff we have today.Īt least I'm pretty sure that’s what I remember from my intro to GIS class.ĭon’t worry, unless you’re an old-school geographer, you don’t need to choose. “Vector is corrector!” the other would retort. The divide between these two data types and the people that use them has raged on for decades. In the world of spatial analysis, there are two major varieties of data: vector and raster.
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