NAME
v.db.reclass - Changes vector category values for an existing vector map
according to results of SQL queries.
(GRASS Vector Program)
SYNOPSIS
v.db.reclass
v.db.reclass help
v.db.reclass [ -d] type=name input=name output=name table=name [key=name] rules=name [TITLE=name]
DESCRIPTION
v.db.reclass allows a user to create a new vector map based on the
reclassification of an existing vector map.
The user provides the program with a rules file, input
vector map name, an output vector map name, and the type of
input map, table, key. There is an option (d) to dissolve common boundaries between
adjoining map areas of the same re-classed category value.
Note:
The dissolve option will work on only those areas which are of the same
conversion category value. If a map area is inside (island) a converted
area and is NOT converted to the same value, its boundaries are output
to the resultant map.
COMMAND LINE OPTIONS
Flags:
- -d
- Dissolve common boundaries (default is no) .
Parameters:
- type=name
- Select area, line, or site.
Options: area, line, site (multiple allowed)
- input=name
- Vector input map name.
- output=name
- Vector output map name.
- table=name
- Database table.
- key=name
- Column corresponding to cats in vector map.
- rules=name
- Name of text file containing reclassification rules. Rules file may contain
on each row either pair:
keyword value
(separated by space) or comment beginning by #(hash).
Definition of new category begins with kyeword cat followed by new category value.
Keyword where specifies SQL where condition and optionaly label keyword
specifies category label.
- TITLE=name
- Title for the resulting vector map.
EXAMPLE
v.db.reclass -d input=land output=land_u type=area
table=tland key=id rules=land.rcl
the rules file contains :
# land reclass file
cat 1
where use = 'E13' and owner = 'Jara Cimrman'
cat 2
where use = 'E14'
label Use type E14
Produces a new vector area file land_u containing 'area'
boundaries from land with area category values selected
from database by SQL select statement: 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.
Any common boundaries are dissolved.
SEE ALSO
v.extract
AUTHOR
R.L. Glenn, USDA, SCS, NHQ-CGIS
from v.reclass to v.db.reclass rewritten by Radim Blazek