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NAME - Convert OGR vectors to GRASS. Available drivers: GRASS,ESRI Shapefile,MapInfo File,UK .NTF,SDTS,TIGER,S57,DGN,VRT,AVCBin,REC,Memory,CSV,GML,KML,GMT,SQLite,ODBC,PGeo,PostgreSQL,MySQL



SYNOPSIS help [-lfcztoe] dsn=string output=name [layer=string[,string,...]] [spatial=float[,float,...]] [where=sql_query] [min_area=float] [type=string[,string,...]] [snap=float] [location=string] [cnames=string[,string,...]] [--overwrite]


List available layers in data source and exit
List available formats and exit
Do not clean polygons (not recommended)
Create 3D output
Do not create attribute table
Override projection (use location's projection)
Extend location extents based on new dataset
Force overwrite of output files


OGR datasource name. Examples:
ESRI Shapefile: directory containing shapefiles
MapInfo File: directory containing mapinfo files
Name for output vector map
OGR layer name. If not given, all available layers are imported. Examples:
ESRI Shapefile: shapefile name
MapInfo File: mapinfo file name
Import subregion only (xmin,ymin,xmax,ymax - usually W,S,E,N)
WHERE conditions of SQL statement without 'where' keyword. (example: income < 1000 and inhab >= 10000)
Minimum size of area to be imported (square units). Smaller areas and islands are ignored. Should be greater than snap^2
Default: 0.0001
Optionaly change default input type:
point -> import area centroids as points
line -> import area boundaries as centroids
boundary -> import lines as area boundaries
centroid -> import points as centroids
Options: point,line,boundary,centroid
Snapping threshold for boundaries. -1 for no snap
Default: -1
Name for new location to create
List of column names to be used instead of original names, first is used for category column

DESCRIPTION converts OGR vectors to GRASS. OGR (Simple Features Library) is part of the GDAL library, so you need to install GDAL to use

If the layer parameter is not given, all available layers are imported.

The optional spatial parameter defines spatial query extents. This parameter allows to restrict the region to a spatial subset while importing the data. All vector completely or partially falling into this rectangle subregion are imported.

Topology cleaning on areas is automatically performed, but may fail in special cases (then use v.clean).

Supported OGR Vector Formats

ESRI Shapefile
Mapinfo File

Further available drivers such as UK .NTF, SDTS, TIGER, IHO S-57 (ENC), DGN, GML, AVCBin, REC, Memory, OGDI, and PostgreSQL depend on the local installation (OGR library), for details see OGR web site.

Location Creation attempts to preserve projection information when importing datasets if the source format includes projection information, and if the OGR driver supports it. If the projection of the source dataset does not match the projection of the current location will report an error message ("Projection of dataset does not appear to match current location") and then report the PROJ_INFO parameters of the source dataset.

If the user wishes to ignore the difference between the apparent coordinate system of the source data and the current location, they may pass the -o flag to override the projection check.

If the user wishes to import the data with the full projection definition, it is possible to have automatically create a new location based on the projection and extents of the file being read. This is accomplished by passing the name to be used for the new location via the location parameter. Upon completion of the command, a new location will have been created (with only a PERMANENT mapset), and the vector map will have been imported with the indicated output name into the PERMANENT mapset.


The command imports various vector formats:

Support of database schema:

For schema support, first set a default schema with db.connect. If schema support is used the schema name must be specified whenever a db.* module is called.


  db.connect driver=pg database=test schema=user1 group=group1
  db.login driver=pg database=test user=user1 password=pwd1 dsn=./ layer=river output=river     # -> table user1.river table=user1.river
The user can ignore schemas, if desired:
  db.connect driver=pg database=test
  db.login driver=pg database=test user=user1 password=pwd1 dsn=./ layer=river output=river     # -> table public.river table=river


The characters used for table column names are limited. Supported are:
This means that SQL neither supports '.' (dots) nor '-' (minus) nor '#' in table column names. Also a table name must start with a character, not a number. converts '.', '-' and '#' to '_' (underscore) during import. Use the cnames parameter to define new column names during import.

The DBF database specification limits column names to 10 characters. If the default DB is set to DBF and the input data contains longer column/field names, they will be truncated. If this results in multiple columns with the same name then will produce an error. In this case you will either have to modify the input data or use's cnames parameter to rename columns to something unique. (hint: copy & modify the list given with the error message). Alternatively, change the local DB with db.connect.

If a message like "WARNING: Area size 1.3e-06, area not imported." appears, the min_area may be adjusted to a smaller value so that all areas are imported. Otherwise tiny areas are filtered out during import (useful to polish digitization errors or non-topological data).


OGR vector library
OGR vector library C API documentation


db.connect, v.clean,, v.external,,, v.out.ogr


Radim Blazek, ITC-Irst, Trento, Italy
Location and spatial extent support by Markus Neteler and Paul Kelly

Last changed: $Date: 2007/07/09 15:01:10 $

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