DESCRIPTION

v.external creates new vector as a link to external OGR layer. OGR (Simple Features Library) is part of the GDAL library, so you need to install GDAL to use v.external and external OGR layers.

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.

EXAMPLES

SHAPE files
v.externalr dsn=/home/user/shape_data layer=test_shape output=grass_map

MapInfo files
v.external dsn=./ layer=mapinfo_test output=grass_map

SDTS files (you have to select the CATD file)
v.external dsn=CITXCATD.DDF output=cities

TIGER files
v.external dsn=input/2000/56015/ layer=CompleteChain,PIP output=t56015_all

PostGIS maps (area example)
v.external dsn="PG:dbname=postgis" layer=polymap output=polygons

REFERENCES

OGR vector library
OGR vector library C API documentation

SEE ALSO

v.clean, v.in.ogr v.out.ogr

AUTHOR

Radim Blazek, ITC-Irst, Trento, Italy

Last changed: $Date: 2004/05/12 08:42:18 $