A region refers to a geographic area with some defined boundaries, based on a specific map coordinate system and map projection. Each region also has associated with it the specific east-west and north-south resolutions of its smallest units (rectangular units called 'cells'). The g.region command allows the user to manage the settings of the current geographic region. These regional boundaries can be set by the user directly and/or set from a region definition file (stored under the windows directory in the user's current mapset). The user can create, modify, and store as many geographic region definitions as desired for any given mapset. However, only one of these geographic region definitions will be current at any given moment, for a specified mapset, i.e., GRASS programs that respect the geographic region settings will use the current geographic region settings. Each mapset has a current geographic region. The 'current region' defines the geographic area in which all GRASS displays and analyses will be done. Data will be resampled, if necessary, to meet the cell resolutions of the current geographic region setting. For example: Region parameters can be changed at any time using the g.region command: option 1 (Modify current region directly) allows the user to directly modify region settings: You can set or save a region from a file, or from the informations stored in the cellhd of a raster map, or from a vector map by running (for example)the command: Every time a parameter of the region settings is changed with g.region, changes will be effectives only after running the command d.erase. Source.


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Last Modified: April 24, 2016 @ 5:06 am