v.category(1)

1v.category(1)                 Grass User's Manual                v.category(1)
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NAME

6       v.category   - Attach, delete or report vector categories to map geome‐
7       try.
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KEYWORDS

10       vector
11

SYNOPSIS

13       v.category
14       v.category help
15       v.category [-g] input=name  [output=name]    [type=string[,string,...]]
16       [option=string]       [cat=integer]       [layer=integer[,integer,...]]
17       [step=integer]   [--overwrite]
18
19   Flags:
20       -g  shell script style, currently only for report
21
22       --overwrite
23
24   Parameters:
25       input=name
26           Name of input vector map
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28       output=name
29           Name for output vector map
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31       type=string[,string,...]
32           Type    Options:     point,line,boundary,centroid,area     Default:
33           point,line,boundary,centroid,area
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35       option=string
36           Action to be done:
37                add  -  add  a new category del - delete category    chlayer -
38           change layer number  (e.g.  layer=3,1  changes  layer  3  to  layer
39           1)     sum  -  add the value specified by cat option to the current
40           category value     report - print  report  (statistics),  in  shell
41           style:         layer  type  count  min max   print - print category
42           values, more cats in the same layer are separated by  '/'  Options:
43           add,del,chlayer,sum,report,print Default: add
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45       cat=integer
46           Category value Default: 1
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48       layer=integer[,integer,...]
49           Layer number Default: 1
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51       step=integer
52           Category increment Default: 1
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DESCRIPTION

55       v.category attaches, deletes or reports vector categories to map geome‐
56       try. These categories (IDs) are  used  to  link  a  vector  map  to  an
57       attribute table.
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NOTES

60       Use v.to.db to upload related categories to a linked attribute table.
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62       The  type parameter specifies the type of geometry objects to which the
63       category is added; it is similar to an input filter - only the geometry
64       specified in 'type' is processed.
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66       If  the  type parameter is set to centroid and the option parameter set
67       to add, new categories will be added to existing centroids.  Note  how‐
68       ever,  that  new  centroids cannot be created this way.  To do so, they
69       must be added manually using v.digit or by running v.category with  the
70       type parameter set to area (see below also).
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72       Areas are a special case because it is impossible to attach a cat to an
73       area without a centroid; in this case, the module places new  centroids
74       in areas automatically.
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EXAMPLES

77       1) Report vector categories
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79       v.category in=testmap option=report
80       LAYER/TABLE 1/testmap:
81       type       count        min        max
82       point          0          0          0
83       line        1379          1       1379
84       boundary       0          0          0
85       centroid       0          0          0
86       area           0          0          0
87       all         1379          1       1379
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89
90       2) Delete all vector categories in layer 1
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92       v.category in=testmap out=outmap option=del
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95       3) Add vector categories in layer 1 with step=2
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97       v.category in=outmap out=stepmap option=add step=2
98       LAYER/TABLE 1/outmap:
99       type       count        min        max
100       point          0          0          0
101       line        1379          1       2757
102       boundary       0          0          0
103       centroid       0          0          0
104       area           0          0          0
105       all         1379          1       2757
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107
108       4) Add categories/centroids to a vector map without categories
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110       v.category in=wkt out=wktnew option=add
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113       Results can be tested using d.what.vect.
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AUTHOR

119       Radim Blazek, ITC-Irst, Trento, Italy
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121       Last changed: $Date: 2006/08/31 14:26:20 $
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123       Full index
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127GRASS 6.2.2                                                      v.category(1)