1v.reclass(1) GRASS GIS 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 ac‐
45 cess 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 al‐
81 phabetical order.
82 For dissolving common boundaries, see v.dissolve.
84 Either the rules or column option must be specified.
86
88 Example 1: Reclass by rules
89 v.reclass input=land output=land_u type=boundary rules=land.rcl
90 The rules file contains:
91 # land reclass file
92 cat 1
93 where use = ’E13’ and owner = ’Jara Cimrman’
94 cat 2
95 where use = ’E14’
96 Produces a new vector area map land_u containing boundaries from land
97 with area category values selected from database by SQL select state‐
98 ment:
99 select id from tland where use = ’E13’ and owner = ’Jara Cimrman’
100 changed to category 1;
101 values selected from database by SQL select statement:
102 select id from tland where use = ’E14’ changed to category 2.
103 Example 2: Reclass by attribute column
105 (North Carolina sample dataset)
106 v.reclass in=streams out=streams_by_type column=I_vs_P
107 v.db.select streams_by_type
108 cat|I_vs_P
109 1|intermittent
110 2|perennial
111
113 No table is created for reclassed layer if the rules option is used.
114
116 v.dissolve, v.extract
117 GRASS SQL interface
119
121 R.L. Glenn, USDA, SCS, NHQ-CGIS
122 from v.reclass to v.db.reclass and later to v.reclass in 5.7 rewritten
123 by Radim Blazek
124
126 Available at: v.reclass source code (history)
127 Accessed: Saturday Oct 28 18:18:46 2023
129 Main index | Vector index | Topics index | Keywords index | Graphical
131 index | Full index
132 © 2003-2023 GRASS Development Team, GRASS GIS 8.3.1 Reference Manual
134GRASS 8.3.1 v.reclass(1)