| ArcGIS
|
GRASS GIS
|
Notes
|
| feature class or feature
|
vector map or vector
|
|
| layer
|
map or map layer
|
When talking about data, GRASS GIS uses term map in mathematical sense of mapping values from one space (geospatial coordinates) to another space (values specifying what's there). When talking about displaying data in the GUI, GRASS GIS talks about map layers (or just layers) as we are putting different layers on top of each other.
|
| Shapefile, shapefile, shape
|
vector map or vector
|
ESRI Shapefile format is of course still called the same. Here we talk about using Shapefile in sense of vector data (which is incorrect, yet common, usage).
|
| (vector) feature
|
vector feature
|
|
| Table of Contents (TOC)
|
Layer Manager, list of map layers
|
|
| feature ID (FID), ObjectID
|
cat, category
|
The term feature ID (fid) is also used in GRASS GIS but it is an internal identifier which user does not have to be concerned about. In GRASS GIS, the term category is used with both raster and vector maps.
|
| (current) workspace
|
(current) Mapset and (current) working directory
|
In GRASS GIS, newly created (raster and vector) maps are saved to the current Mapset (which is in GRASS Location in GRASS database directory). Other data (files) are saved to the path (directory) if specified, or the current working directory if only filename was provided. Note that every program (application) has current working directory, for GUI applications it is usually the user's home directory and they are often not using it.
|
| database
|
Mapset, Location, GRASS GIS database directory, or database (if used in general context)
|
In GRASS GIS, geospatial data are stored in Mapset (which is in GRASS Location in GRASS database directory) as directories and files in GRASS GIS specific format. The attributes of a vector map are stored in a database.
|
| left, right, top, bottom
|
west, east, north, south
|
When specifying 2D extent (bounding box) of data or for computations, ArcGIS uses left, right, top, bottom to name the individual values, while GRASS GIS is using west, east, north, south. In GRASS GIS, top and bottom are used as well but to specify upper and lower limit of a 3D extent (bounding box).
|
| Item description (item in Geodatabase or Data Catalog)
|
metadata or information obtained from r.info, v.info and others
|
Note that in GRASS GIS, there is also a new advanced metadata system available in GRASS GIS Addons repository.
|
| NoData, Null, 0, -9999
|
NULL
|
Missing or unknown data are referred to as NULL data or NULL values in GRASS GIS. Sometimes also other terms such as null(), *, nv, or nodata. Because all numbers can have some meaning in their context, there is no numerical value which would represent NULL value.
|
|
|
|
|
|
|
|
|