Provided by: grass-doc_6.4.3-3_all
v.reclass - Changes vector category values for an existing vector map according to results of SQL queries or a value in attribute table column.
vector, reclass, attributes
v.reclass v.reclass help v.reclass input=name output=name [type=string[,string,...]] [layer=integer] [column=name] [rules=name] [--overwrite] [--verbose] [--quiet] Flags: --overwrite Allow output files to overwrite existing files --verbose Verbose module output --quiet Quiet module output Parameters: input=name Name of input vector map output=name Name for output vector map type=string[,string,...] Feature type Options: point,line,boundary,centroid Default: point,line,boundary,centroid layer=integer Layer number A single vector map can be connected to multiple database tables. This number determines which table to use. Default: 1 column=name The name of the column whose values are to be used as new categories The source for the new key column must be type integer or string rules=name Full path to the reclass rule file
v.reclass allows user to create a new vector map based on the reclassification 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.
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 ambiguities). 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 alphabetical order. For dissolving common boundaries, see v.dissolve.
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 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. 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
No table is created for reclassed layer if rules option is used.
v.dissolve, v.extract GRASS SQL interface
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 Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $ Full index © 2003-2013 GRASS Development Team