NAME

v.in.shape - Read an ArcView Shapefile

SYNOPSIS

v.in.shape input=name [mapset=name]
[verbose=debug level] [logfile=name] [snapdist=snap distance]
[sliver=min. angle] [scale=orig. scale] [attribute=attribute category]
[label=category label]

DESCRIPTION

The v.in.shape program is designed to import ArcView Shapefiles.

v.in.shape will be run non-interactively if the user specifies program arguments on the command line, using the form:
 
v.in.shape input=name [mapset=name]
[verbose=debug level] [logfile=name] [snapdist=snap distance]
[sliver=min. angle] [scale=orig. scale] [attribute=attribute category]
[label=category label]

Alternately, the user can simply type:

v.in.shape

on the command line without program arguments. In this case, the user will be prompted for parameter values using the standard GRASS user interface described in the manual entry for parser.

FEATURES

Grass files created have the name extracted from the basename of the shapefile.

The import filter attempts to correct some common errors that are frequently met with in shapefiles.

OPTIONS

input=name Name of input shape file. Provide a full path name or the name of a file in the current directory. The .shp extension is required.
mapset=name For creating a new mapset for the data imported. This may be usefull, since we cannot create a projection info file and a default window in an existing mapset. When a file is imported in the current mapset, you should take care that they are in the same projection.

Unfortunately, you may run in trouble after that when using g.region (Cf BUGS).

verbose=debug level

logfile=name

Number between 0 (no trace of what's happening) and 9 (very verbose log).

Name of file where log info will be written. By default log info are directed to stderr.

snapdist=snap distance
 
A grid resolution can be defined within which adjacent vertices will snap.

Note:The vertices do not snap to the grid. All the vertices inside a grid cell snap to one of their number (usually the first).

This value defaults to 0.001 ground units. In fact, it will never allow a value that is less.

sliver=minimum angle
A minimum angle can be defined for one link to subtend others at a given node. If the angle between two lines is less than this, they will be treated as colinear. This can be useful as the module now has features which attempt to correct some common topological errors that occur in the immediate vicinity of nodes. If you can be confident that true angles between adjacent arcs radiating from the same node cannot be less than a certain value, you can specify that value here, and some errors may be automatically corrected. This defaults to .01 degrees (specified in radians). In fact it will never allow a value that is less
scale=original scale This sets an original scale that will be specified in the header of the vector map file pro- duced. It can be edited later with v.digit.

The value defaults to 1:2400

attribute=a_name Name of the attribute to use as the category number in dig_att. Give a value of list to see a list of available attributes.
label=a_label Name of the attribute to use as the category label in dig_cats. Give a value of list to see a
list of available attributes.

BUGS AND CAVEAT

There is no support for projection.

Multipatch data is not yet supported. Point data (sites) also is not handled by this module. New module s.in.shape

imports site data.

SEE ALSO

m.in.e00, g.mapset, g.region, v.digit, v.proj, s.in.shape, v.support, v.to.rast.

AUTHORS

Frank Warmerdam (warmerda@home.com)
Based on Shapelib (http://gdal.velocet.ca/projects/shapelib/).

Markus Neteler
added category support

David Gray
preprocessing to provide correct handling of polygon edges, labels and correction of some topological errors. Also some new options q.v.