<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <html> <head> <title>GRASS GIS: v.reclass</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <link rel="stylesheet" href="grassdocs.css" type="text/css"> </head> <body bgcolor="white"> <img src="grass_logo.png" alt="GRASS logo"><hr align=center size=6 noshade> <h2>NAME</h2> <em><b>v.reclass</b></em> - Changes vector category values for an existing vector map according to results of SQL queries or a value in attribute table column. <h2>KEYWORDS</h2> vector, attribute table <h2>SYNOPSIS</h2> <b>v.reclass</b><br> <b>v.reclass help</b><br> <b>v.reclass</b> <b>input</b>=<em>name</em> <b>output</b>=<em>name</em> [<b>rules</b>=<em>string</em>] [<b>column</b>=<em>string</em>] [<b>type</b>=<em>string</em>[,<i>string</i>,...]] [<b>layer</b>=<em>integer</em>] [--<b>overwrite</b>] [--<b>verbose</b>] [--<b>quiet</b>] <h3>Flags:</h3> <DL> <DT><b>--overwrite</b></DT> <DD>Allow output files to overwrite existing files</DD> <DT><b>--verbose</b></DT> <DD>Verbose module output</DD> <DT><b>--quiet</b></DT> <DD>Quiet module output</DD> </DL> <h3>Parameters:</h3> <DL> <DT><b>input</b>=<em>name</em></DT> <DD>Name of input vector map</DD> <DT><b>output</b>=<em>name</em></DT> <DD>Name for output vector map</DD> <DT><b>rules</b>=<em>string</em></DT> <DD>Full path to the reclass rule file</DD> <DT><b>column</b>=<em>string</em></DT> <DD>The name of the column values of which are used as new categories. The column must be type integer.</DD> <DT><b>type</b>=<em>string[,<i>string</i>,...]</em></DT> <DD>Type</DD> <DD>Select type</DD> <DD>Options: <em>point,line,boundary,centroid</em></DD> <DD>Default: <em>point,line,boundary,centroid</em></DD> <DT><b>layer</b>=<em>integer</em></DT> <DD>Layer number</DD> <DD>A single vector map can be connected to multiple database tables. This number determines which table to use.</DD> <DD>Default: <em>1</em></DD> </DL> <H2>DESCRIPTION</H2> <EM>v.reclass</EM> allows user to create a new vector map based on the reclassification of an existing vector map. <BR><BR> Rules file may contain on each row either pair: <BR> <I>keyword value</I> <BR> (separated by space) or comment beginning by #(hash). Definition of new category begins with keyword <I>cat</I> followed by new category value. Keyword <I>where</I> specifies SQL where condition. <H2>EXAMPLE</H2> <div class="code"><pre> v.reclass input=land output=land_u type=boundary rules=land.rcl </pre></div> <P> the rules file contains : <div class="code"><pre> # land reclass file cat 1 where use = 'E13' and owner = 'Jara Cimrman' cat 2 where use = 'E14' </pre></div> Produces a new vector area map <EM>land_u</EM> containing boundaries from <EM>land</EM> with area category values selected from database by SQL select statement: <br> <I>select id from tland where use = 'E13' and owner = 'Jara Cimrman' </I> changed to category 1; <br> values selected from database by SQL select statement: <br> <I>select id from tland where use = 'E14' </I> changed to category 2. <BR> <P> <H2>NOTES</H2> No table is created for reclassed layer if <B>column</B> option is used and column type is integer (there is nothing which could be written to the table). <P> For dissolving common boundaries, see <em>v.extract</em>. <P> <H2>BUGS</H2> No table is created for reclassed layer if <B>rules</B> option is used. <P> <H2>SEE ALSO</H2> <em><a HREF="v.dissolve.html">v.dissolve</a></em>, <em><A HREF="v.extract.html">v.extract</A></em>, <em><a HREF="v.reclass.html">v.reclass</a></em>, <em><a HREF="sql.html">GRASS SQL interface</a></em> <H2>AUTHOR</H2> R.L. Glenn, USDA, SCS, NHQ-CGIS<BR> from v.reclass to v.db.reclass and later to v.reclass in 5.7 rewritten by Radim Blazek <p><i>Last changed: $Date: 2007-05-18 10:30:19 +0200 (Fri, 18 May 2007) $</i> <HR> <P><a href="index.html">Main index</a> - <a href="vector.html">vector index</a> - <a href="full_index.html">Full index</a></P> <P>© 2003-2008 <a href="http://grass.osgeo.org">GRASS Development Team</a></p> </body> </html>
