GRASS 6 Tutorial/Vector data management: Difference between revisions
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===Vector | ==Vector data management== | ||
===Overview=== | |||
The native GRASS vector format provides: | |||
*Vector topology | |||
*m:n mapping of geometry features to attributes | |||
*Vector layers | |||
*OGC Simple Features <-> Topological Vector Conversion | |||
*Database Management system (DBMS) | |||
*SQLite, PostgreSQL + PostGIS, MySQL, ODBC (, DBF) | |||
The vector geometry types supported in GRASS include: | |||
*Point | |||
*Centroid | |||
*Line | |||
*Boundary | |||
*Area (Boundaries + Centroid) | |||
*Face (3D Area) | |||
*[Kernel (3D Centroid)] | |||
*[Volumes (Faces + Kernel)] | |||
All types are '''true 3D''': x,y,z | |||
===Import/Export of Vector data=== | |||
The GRASS modules <code>v.in.*</code> and <code>v.out.*</code> handle the importing and exporting of Vector datasets. | |||
<code>v.in.ogr</code> is widely used and has simplified the import of vector data; [http://www.gdal.org/ogr/ogr_formats.html OGR] itself support a wide range of formats. | |||
<code>v.out.ogr</code> always exports the entire vector map | |||
====Importing an ESRI Shapefile==== | |||
The following code snippet is a simple usage of <code>v.in.ogr</code>, which imports an ESRI Shapefile from the command line as follows: | |||
v.in.ogr dsn=boundary_county.shp out=boundary_county | |||
However, <code>v.in.ogr</code> has many options to import subsets (defined spatially or by SQL) and vector types | |||
The same can be achieved using the GRASS Graphical Interface. The Vector import interface can be accessed through the vector layer manager: | |||
[[File:Vector_layer_manager.png|400px]] | |||
[[File:Vector_layer_import.png|400px]] | |||
Introductory information on [http://grass.ibiblio.org/grass63/manuals/html63_user/vectorintro.html vector data processing] is available from the help manual. | |||
===[[Grass Six Tutorial Default Settings]]=== | |||
- Default settings for vector geometry; | |||
for vector attributes; for db.* modules | |||
===[[Grass Six Tutorial Geometry Management]]=== | |||
http://grass.osgeo.org/grass57/tutorial/geom_storage.html | |||
- General notes on Geometry | |||
management; Managing the default settings; | |||
GRASS vector architecture; Geometry stored in native format; | |||
Geometry stored in SHAPE file; | |||
Import/export of vector data Geometry; | |||
Generating vector geometry from various sources | |||
===[[Grass Six Tutorial Attribute Management]]=== | |||
http://grass.osgeo.org/grass57/tutorial/attrib_storage.html | |||
- General notes on Attribute | |||
management; Managing the default settings; Examples; | |||
Database Schema |
Revision as of 13:05, 7 November 2012
Vector data management
Overview
The native GRASS vector format provides:
- Vector topology
- m:n mapping of geometry features to attributes
- Vector layers
- OGC Simple Features <-> Topological Vector Conversion
- Database Management system (DBMS)
- SQLite, PostgreSQL + PostGIS, MySQL, ODBC (, DBF)
The vector geometry types supported in GRASS include:
- Point
- Centroid
- Line
- Boundary
- Area (Boundaries + Centroid)
- Face (3D Area)
- [Kernel (3D Centroid)]
- [Volumes (Faces + Kernel)]
All types are true 3D: x,y,z
Import/Export of Vector data
The GRASS modules v.in.*
and v.out.*
handle the importing and exporting of Vector datasets.
v.in.ogr
is widely used and has simplified the import of vector data; OGR itself support a wide range of formats.
v.out.ogr
always exports the entire vector map
Importing an ESRI Shapefile
The following code snippet is a simple usage of v.in.ogr
, which imports an ESRI Shapefile from the command line as follows:
v.in.ogr dsn=boundary_county.shp out=boundary_county
However, v.in.ogr
has many options to import subsets (defined spatially or by SQL) and vector types
The same can be achieved using the GRASS Graphical Interface. The Vector import interface can be accessed through the vector layer manager:
Introductory information on vector data processing is available from the help manual.
Grass Six Tutorial Default Settings
- Default settings for vector geometry; for vector attributes; for db.* modules
Grass Six Tutorial Geometry Management
http://grass.osgeo.org/grass57/tutorial/geom_storage.html
- General notes on Geometry management; Managing the default settings; GRASS vector architecture; Geometry stored in native format; Geometry stored in SHAPE file; Import/export of vector data Geometry; Generating vector geometry from various sources
Grass Six Tutorial Attribute Management
http://grass.osgeo.org/grass57/tutorial/attrib_storage.html
- General notes on Attribute management; Managing the default settings; Examples; Database Schema