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NAME

KEYWORDS

SYNOPSIS

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

option=string

Action to be done

Options: add,del,chlayer,sum,report,print,layers

Default: add

add: add a category to features without category in the given layer

del: delete all categories of given layer

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 '/'

layers: print only layer numbers

type=string[,string,...]

Feature type

Options: point,line,boundary,centroid,area

Default: point,line,boundary,centroid,area

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

ids=range

Feature ids (by default all features are processed)

Example: 1,3,7-9,13

cat=integer

Category value

Default: 1

step=integer

Category increment

Default: 1

DESCRIPTION

NOTES

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.

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 cat parameter is only used with option=add and option=sum.

The ids parameter specifies the list of feature IDs to which the operation is performed; by default, all vector feature ids are processed. The feature ID is an internal (unique) geometry ID that all vector primitives possess, and is separate from any category the feature may also possess. Use

  v.edit map=inputname tool=select

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

v.category input=roads option=print layer=1 id=1-50

SEE ALSO

AUTHOR

Last changed: $Date: 2011-11-08 01:42:51 -0800 (Tue, 08 Nov 2011) $

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