NAME
v.category - Attach, delete or report vector categories to map geometry.
KEYWORDS
vector, category
SYNOPSIS
v.category
v.category help
v.category [-g] input=name [output=name] [type=string[,string,...]] [option=string] [cat=integer] [layer=integer[,integer,...]] [step=integer] [id=integer[,integer,...]] [--overwrite] [--verbose] [--quiet]
Flags:
- -g
- Shell script style, currently only for report
- Format: layer type count min max
- --overwrite
- Allow output files to overwrite existing files
- --verbose
- Verbose module output
- --quiet
- Quiet module output
Parameters:
- input=name
- Name of input vector map
- output=name
- Name for output vector map
- type=string[,string,...]
- Type
- Feature type(s)
- Options: point,line,boundary,centroid,area
- Default: point,line,boundary,centroid,area
- option=string
- Action to be done
- Options: add,del,chlayer,sum,report,print
- Default: add
- add: add a new category
- del: delete category
- chlayer: change layer number (e.g. layer=3,1 changes layer 3 to layer 1)
- sum: add the value specified by cat option to the current category value
- report: print report (statistics), in shell style: layer type count min max
- print: print category values, more cats in the same layer are separated by '/'
- cat=integer
- Category value
- Default: 1
- layer=integer[,integer,...]
- Layer number
- A single vector map can be connected to multiple database tables. This number determines which table to use.
- Default: 1
- step=integer
- Category increment
- Default: 1
- id=integer[,integer,...]
- Feature id(s)
- By default all ids are processed
DESCRIPTION
v.category attaches, deletes or reports vector categories to
map geometry. These categories (IDs) are used to link geometry
object(s) to attribute record (from attribute table linked to vector map).
NOTES
Use v.to.db to upload related categories to
a linked attribute table.
The type parameter specifies the type of geometry objects to which the category is added;
it is similar to an input filter - only the geometry specified in 'type' is processed.
If the type parameter is set to centroid and
the option parameter set to add, new categories will be
added to existing centroids. Note however, that new centroids cannot
be created this way. To do so, they must be added manually
using v.digit or by
running v.category with the type parameter set to area (see
below also).
Areas are a special case because it is impossible to attach a cat to an area without a centroid;
in this case, the module places new centroids in areas automatically.
The id parameter specifies the list of feature ids to which the
operation is performed. By default all vector features are processed.
EXAMPLES
Report vector categories
v.category input=testmap option=report
LAYER/TABLE 1/testmap:
type count min max
point 0 0 0
line 1379 1 1379
boundary 0 0 0
centroid 0 0 0
area 0 0 0
all 1379 1 1379
Delete all vector categories in layer 1
v.category input=testmap output=outmap option=del
Add vector categories in layer 1 with step=2
v.category input=outmap output=stepmap option=add step=2
# report
v.category input=stepmap option=report
LAYER/TABLE 1/outmap:
type count min max
point 0 0 0
line 1379 1 2757
boundary 0 0 0
centroid 0 0 0
area 0 0 0
all 1379 1 2757
Add categories/centroids to a vector map without categories
v.category input=wkt output=wktnew option=add
Print vector categories of given layer
Print vector categories from the first layer, only for feature ids 1-50.
v.category input=roads option=print layer=1 id=1-50
SEE ALSO
v.db.connect,
v.to.db
AUTHOR
Radim Blazek, ITC-irst, Trento, Italy
Modified (the id parameter) by Martin Landa, FBK-irst (formerly ITC-irst), Trento, Italy, 2008/02
Last changed: $Date: 2008-02-02 09:18:31 -0800 (Sat, 02 Feb 2008) $
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