GGR272H1 Lecture Notes - Lecture 2: Gnu Debugger, Microsoft Access, Spatial Database
7 Sep 2016
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Document Summary
A geographical information system (gis) is a system used to describe and characterize the earth and other geographies for the purpose of visualizing and analyzing spatially referenced information. A map is a simplified version of reality. What goes on a map is determined by the purpose of the map to decided what will be included or excluded on it. Data model: way of organizing and representing data that are simplified version of reality. In gis we divided real world into two parts: discrete objects & continuous phenomena. Vector data model: everything that we want to show can only be described or represented with. Facts and figures found in a chart are seen as the attributes (table) o o. A row in a table is called a record. A column in a table is called a field. Everything is as precise as the scale. Raster data model: represented with squares/grid (pixels/data cells) on a continuous surface.
