v.reclass(1grass) GRASS GIS User's Manual v.reclass(1grass)
NAME
v.reclass - Changes vector category values for an existing vector map
according to results of SQL queries or a value in attribute table col-
umn.
KEYWORDS
vector, reclassification, attributes
SYNOPSIS
v.reclass
v.reclass --help
v.reclass input=name [layer=string] [type=string[,string,...]] out-
put=name [column=name] [rules=name] [--overwrite] [--help]
[--verbose] [--quiet] [--ui]
Flags:
--overwrite
Allow output files to overwrite existing files
--help
Print usage summary
--verbose
Verbose module output
--quiet
Quiet module output
--ui
Force launching GUI dialog
Parameters:
input=name [required]
Name of input vector map
Or data source for direct OGR access
layer=string
Layer number or name
Vector features can have category values in different layers. This
number determines which layer to use. When used with direct OGR ac-
cess this is the layer name.
Default: 1
type=string[,string,...]
Input feature type
Options: point, line, boundary, centroid
Default: point,line,boundary,centroid
output=name [required]
Name for output vector map
column=name
The name of the column whose values are to be used as new cate-
gories
The source for the new key column must be type integer or string
rules=name
Full path to the reclass rule file
DESCRIPTION
v.reclass allows user to create a new vector map based on the reclassi-
fication of an existing vector map. It also allows the user to change
the key column away from the default of "cat" with the column option.
Rules file may contain on each row either pair:
keyword value
(separated by space) or comment beginning with ’#’ (hash). Definition
of new category begins with keyword cat followed by the new category
value. Keyword where specifies SQL where condition.
NOTES
No table is created for the reclassed map if the column option is used
and the column type is integer (as the result could contain ambigui-
ties). If the column option is used and the column type is string, a
new table is created containing the newly generated cat numbers and a
single column containing the unique string column values, sorted in al-
phabetical order.
For dissolving common boundaries, see v.dissolve.
EXAMPLES
Example 1: Reclass by rules
v.reclass input=land output=land_u type=boundary rules=land.rcl
the rules file contains :
# land reclass file
cat 1
where use = ’E13’ and owner = ’Jara Cimrman’
cat 2
where use = ’E14’
Produces a new vector area map land_u containing boundaries from land
with area category values selected from database by SQL select state-
ment:
select id from tland where use = ’E13’ and owner = ’Jara Cimrman’
changed to category 1;
values selected from database by SQL select statement:
select id from tland where use = ’E14’ changed to category 2.
Example 2: Reclass by attribute column
(North Carolina sample dataset)
v.reclass in=streams out=streams_by_type column=I_vs_P
v.db.select streams_by_type
cat|I_vs_P
1|intermittent
2|perennial
KNOWN ISSUES
No table is created for reclassed layer if rules option is used.
SEE ALSO
v.dissolve, v.extract
GRASS SQL interface
AUTHOR
R.L. Glenn, USDA, SCS, NHQ-CGIS
from v.reclass to v.db.reclass and later to v.reclass in 5.7 rewritten
by Radim Blazek
SOURCE CODE
Available at: v.reclass source code (history)
Accessed: unknown
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GRASS 7.8.7 v.reclass(1grass)
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