1v.reclass(1) Grass User's Manual v.reclass(1)
2
6 v.reclass - Changes vector category values for an existing vector map
7 according to results of SQL queries or a value in attribute table col‐
8 umn.
9
11 vector, reclassification, attributes
12
14 v.reclass
15 v.reclass --help
16 v.reclass input=name [layer=string] [type=string[,string,...]] out‐
17 put=name [column=name] [rules=name] [--overwrite] [--help]
18 [--verbose] [--quiet] [--ui]
19 Flags:
21 --overwrite
22 Allow output files to overwrite existing files
23 --help
25 Print usage summary
26 --verbose
28 Verbose module output
29 --quiet
31 Quiet module output
32 --ui
34 Force launching GUI dialog
35 Parameters:
37 input=name [required]
38 Name of input vector map
39 Or data source for direct OGR access
40 layer=string
42 Layer number or name
43 Vector features can have category values in different layers. This
44 number determines which layer to use. When used with direct OGR
45 access this is the layer name.
46 Default: 1
47 type=string[,string,...]
49 Input feature type
50 Options: point, line, boundary, centroid
51 Default: point,line,boundary,centroid
52 output=name [required]
54 Name for output vector map
55 column=name
57 The name of the column whose values are to be used as new cate‐
58 gories
59 The source for the new key column must be type integer or string
60 rules=name
62 Full path to the reclass rule file
63
65 v.reclass allows user to create a new vector map based on the reclassi‐
66 fication of an existing vector map. It also allows the user to change
67 the key column away from the default of "cat" with the column option.
68 Rules file may contain on each row either pair:
70 keyword value
71 (separated by space) or comment beginning with ’#’ (hash). Definition
72 of new category begins with keyword cat followed by the new category
73 value. Keyword where specifies SQL where condition.
74
76 No table is created for the reclassed map if the column option is used
77 and the column type is integer (as the result could contain ambigui‐
78 ties). If the column option is used and the column type is string, a
79 new table is created containing the newly generated cat numbers and a
80 single column containing the unique string column values, sorted in
81 alphabetical order.
82 For dissolving common boundaries, see v.dissolve.
84
86 Example 1: Reclass by rules
87 v.reclass input=land output=land_u type=boundary rules=land.rcl
88 the rules file contains :
89 # land reclass file
90 cat 1
91 where use = ’E13’ and owner = ’Jara Cimrman’
92 cat 2
93 where use = ’E14’
94 Produces a new vector area map land_u containing boundaries from land
95 with area category values selected from database by SQL select state‐
96 ment:
97 select id from tland where use = ’E13’ and owner = ’Jara Cimrman’
98 changed to category 1;
99 values selected from database by SQL select statement:
100 select id from tland where use = ’E14’ changed to category 2.
101 Example 2: Reclass by attribute column
103 (North Carolina sample dataset)
104 v.reclass in=streams out=streams_by_type column=I_vs_P
105 v.db.select streams_by_type
106 cat|I_vs_P
107 1|intermittent
108 2|perennial
109
111 No table is created for reclassed layer if rules option is used.
112
114 v.dissolve, v.extract
115 GRASS SQL interface
117
119 R.L. Glenn, USDA, SCS, NHQ-CGIS
120 from v.reclass to v.db.reclass and later to v.reclass in 5.7 rewritten
121 by Radim Blazek
122
124 Available at: v.reclass source code (history)
125 Main index | Vector index | Topics index | Keywords index | Graphical
127 index | Full index
128 © 2003-2019 GRASS Development Team, GRASS GIS 7.8.2 Reference Manual
130GRASS 7.8.2 v.reclass(1)