NAME

       v.reclass   -  Changes  vector  category  values  for  an existing vector map according to results of SQL
       queries or a value in attribute table column.

KEYWORDS

       vector, reclass, attributes

SYNOPSIS

       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

DESCRIPTION

       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.

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 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.

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 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

BUGS

       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

       Last changed: $Date: 2011-11-08 03:29:50 -0800 (Tue, 08 Nov 2011) $

       Full index

       © 2003-2013 GRASS Development Team

GRASS 6.4.3                                                                                    v.reclass(1grass)