Provided by: grass-doc_6.4.3-3_all 
NAME
v.in.ogr - Convert OGR vector layers to GRASS vector map.
KEYWORDS
vector, import
SYNOPSIS
v.in.ogr
v.in.ogr help
v.in.ogr [-lfcztorew] [dsn=string] [output=name] [layer=string[,string,...]]
[spatial=xmin,ymin,xmax,ymax[,xmin,ymin,xmax,ymax,...]] [where=sql_query]
[min_area=float] [type=string[,string,...]] [snap=float] [location=string]
[cnames=string[,string,...]] [--overwrite] [--verbose] [--quiet]
Flags:
-l
List available layers in data source and exit
-f
List supported formats and exit
-c
Do not clean polygons (not recommended)
-z
Create 3D output
-t
Do not create attribute table
-o
Override dataset projection (use location's projection)
-r
Limit import to the current region
-e
Extend region extents based on new dataset
Also updates the default region if in the PERMANENT mapset
-w
Change column names to lowercase characters
--overwrite
Allow output files to overwrite existing files
--verbose
Verbose module output
--quiet
Quiet module output
Parameters:
dsn=string
OGR datasource name
Examples:
ESRI Shapefile: directory containing shapefiles MapInfo File:
directory containing mapinfo files
output=name
Name for output vector map
layer=string[,string,...]
OGR layer name. If not given, all available layers are imported
Examples:
ESRI Shapefile: shapefile name MapInfo File: mapinfo file name
spatial=xmin,ymin,xmax,ymax[,xmin,ymin,xmax,ymax,...]
Import subregion only
Format: xmin,ymin,xmax,ymax - usually W,S,E,N
where=sql_query
WHERE conditions of SQL statement without 'where' keyword
Example: income = 10000
min_area=float
Minimum size of area to be imported (square units)
Smaller areas and islands are ignored. Should be greater than snap^2
Default: 0.0001
type=string[,string,...]
Optionally change default input type
Options: point,line,boundary,centroid
Default:
point: import area centroids as points
line: import area boundaries as lines
boundary: import lines as area boundaries
centroid: import points as centroids
snap=float
Snapping threshold for boundaries
’-1' for no snap
Default: -1
location=string
Name for new location to create
cnames=string[,string,...]
List of column names to be used instead of original names, first is used for category
column
DESCRIPTION
v.in.ogr converts OGR vectors to GRASS. OGR (Simple Features Library) is part of the GDAL
library, so you need to install GDAL to use v.in.ogr.
If the layer parameter is not given, all available layers are imported as separate GRASS
layers into one GRASS vector map. If several OGR layer names are given, all these layers
are imported as separate GRASS layers into one GRASS vector map.
The optional spatial parameter defines spatial query extents. This parameter allows the
user to restrict the region to a spatial subset while importing the data. All vector
features completely or partially falling into this rectangle subregion are imported. The
-r current region flag is identical, but uses the current region settings as the spatial
bounds (see g.region).
Topology cleaning on areas is automatically performed, but may fail in special cases (then
use v.clean).
The min_area threshold value is being specified as area size in map units with the
exception of latitude-longitude locations in which it is being specified solely in square
meters.
The snap threshold value is used to snap boundary vertices to each other if the distance
in map units between two vertices is not larger than the threshold. Snapping is by default
disabled with -1. See also the v.clean manual.
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.
Overlapping polygons
When importing overlapping polygons, the overlapping parts will become new areas with
multiple categories, one unique category for each original polygon. An original polygon
will thus be converted to multiple areas with the same shared category. These multiple
areas will therefore also link to the same entry in the attribute table. A single category
value may thus refer to multiple non-overlapping areas which together represent the
original polygon overlapping with another polygon. The original polygon can be recovered
by using v.extract with the desired category value or where statement and the -d flag to
dissolve common boundaries.
Location Creation
v.in.ogr 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
v.in.ogr 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 v.in.ogr 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.
EXAMPLES
The command imports various vector formats:
SHAPE files
v.in.ogr dsn=/home/user/shape_data/test_shape.shp output=grass_map
Alternate method:
v.in.ogr dsn=/home/user/shape_data layer=test_shape output=grass_map
MapInfo files
v.in.ogr dsn=./ layer=mapinfo_test output=grass_map
Arc Coverage
We import the Arcs and Label points, the module takes care to build areas:
v.in.ogr dsn=gemeinden layer=LAB,ARC type=centroid,boundary output=mymap
E00 file (see also v.in.e00)
First we have to convert the E00 file to an Arc Coverage with 'avcimport'
(AVCE00 tools, use e00conv first in case that avcimport fails):
avcimport e00file coverage
v.in.ogr dsn=coverage layer=LAB,ARC type=centroid,boundary output=mymap
SDTS files (you have to select the CATD file)
v.in.ogr dsn=CITXCATD.DDF output=cities
TIGER files
v.in.ogr dsn=input/2000/56015/ layer=CompleteChain,PIP output=t56015_all \
type=boundary,centroid snap=-1
PostGIS maps (area example)
v.in.ogr dsn="PG:host=localhost dbname=postgis user=postgres" layer=polymap
\
output=polygons type=boundary,centroid
Oracle Spatial maps
Note that you have to set the environment-variables ORACLE_BASE, ORACLE_SID,
ORACLE_HOME and TNS_ADMIN accordingly.
v.in.ogr dsn=OCI:username/password@database_instance output=grasslayer
layer=roads_oci
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.
Example:
db.connect driver=pg database=test schema=user1 group=group1
db.login driver=pg database=test user=user1 password=pwd1
v.in.ogr dsn=./ layer=river output=river # -> table user1.river
db.select 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
v.in.ogr dsn=./ layer=river output=river # -> table public.river
db.select table=river
NOTES
The characters used for table column names are limited. Supported are:
[A-Za-z][A-Za-z0-9_]*
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.
v.in.ogr converts '.', '-' and '#' to '_' (underscore) during import. The -w flag changes
capital column names to lowercase characters as a convenience for SQL usage (lowercase
column names avoid the need to quote them if the attribute table is stored in a SQL DBMS
such as PostgreSQL). The cnames parameter is used 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 v.in.ogr will produce an
error. In this case you will either have to modify the input data or use v.in.ogr's
cnames parameter to rename columns to something unique. (hint: copy and modify the list
given with the error message). Alternatively, change the local DB with db.connect.
WARNINGS
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).
ERROR MESSAGES
"ERROR: DBMI-DBF driver error: SQL parser error: syntax error, unexpected DESC, expecting
NAME processing 'DESC'"
indicates that a column name corresponds to a reserved SQL word (here: 'DESC'). A
different column name should be used. The cnames parameter can be used to assign different
column names on the fly.
"ERROR: Projection of dataset does not appear to match the current location."
You need to create a location whose projection matches the data you wish to import. Try
using location parameter to create a new location based upon the projection information in
the file. If desired, you can then re-project it to another location with v.proj.
REFERENCES
OGR vector library
OGR vector library C API documentation
SEE ALSO
db.connect, v.clean, v.extract, v.build.polylines, v.edit, v.external, v.in.db, v.in.e00,
v.out.ogr,
PostGIS driver
AUTHOR
Radim Blazek, ITC-irst, Trento, Italy
Location and spatial extent support by Markus Neteler and Paul Kelly
Last changed: $Date: 2012-08-21 12:23:56 -0700 (Tue, 21 Aug 2012) $
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