<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
<html>
<head>
<title>GRASS GIS: r.clump</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>r.clump</b></em> - Recategorizes data in a raster map layer by grouping cells that form physically discrete areas into unique categories.
<h2>KEYWORDS</h2>
raster
<h2>SYNOPSIS</h2>
<b>r.clump</b><br>
<b>r.clump help</b><br>
<b>r.clump</b> [-<b>q</b>] <b>input</b>=<em>name</em> <b>output</b>=<em>name</em> [<b>title</b>=<em>"string"</em>] [--<b>overwrite</b>] [--<b>verbose</b>] [--<b>quiet</b>]
<h3>Flags:</h3>
<DL>
<DT><b>-q</b></DT>
<DD>Run quietly</DD>
<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 raster map</DD>
<DT><b>output</b>=<em>name</em></DT>
<DD>Name for output raster map</DD>
<DT><b>title</b>=<em>"string"</em></DT>
<DD>Title, in quotes</DD>
</DL>
<h2>DESCRIPTION</h2>
<em>r.clump</em> finds all areas of contiguous cell category values in the
input raster map layer <em>name.</em> It assigns a unique category value
to each such area ("clump") in the resulting output raster map layer
<em>name.</em>
Category distinctions in the input raster map layer are preserved. This
means that if distinct category values are adjacent, they will NOT be
clumped together. (The user can run <em><A
HREF="r.reclass.html">r.reclass</a></em> prior to <em>r.clump</em> to
recategorize cells and reassign cell category values.)
<h2>NOTES</h2>
<em>r.clump</em> moves a 2x2 matrix over the input raster map layer.
The lower right-hand corner of the matrix is grouped with the cells above it,
or to the left of it (diagonal cells are not considered.)
<p>
<em>r.clump</em> works properly with raster map layers that
contain only "fat" areas (more than a single cell in
width). Linear elements (lines that are a single cell
wide) may or may not be clumped together depending on the
direction of the line - horizontal and vertical lines of
cells are considered to be contiguous, but diagonal lines
of cells are not considered to be contiguous and are broken
up into separate clumps.
<p>
A random color table and other support files are
generated for the <em>output</em> raster map layer.
<h2>SEE ALSO</h2>
<em><a href="r.average.html">r.average</a></em><br>
<em><a href="r.buffer.html">r.buffer</a></em><br>
<em><a href="r.grow.html">r.grow</a><br></em><br>
<em><a href="r.mapcalc.html">r.mapcalc</a></em><br>
<em><a href="r.mfilter.html">r.mfilter</a></em><br>
<em><a href="r.neighbors.html">r.neighbors</a></em><br>
<em><a href="r.to.vect.html">r.to.vect</a></em><br>
<em><a href="r.reclass.html">r.reclass</a></em><br>
<em><a href="r.statistics.html">r.statistics</a></em><br>
<em><a href="r.support.html">r.support</a></em>
<h2>AUTHOR</h2>
Michael Shapiro, U.S. Army Construction Engineering
Research Laboratory
<p><i>Last changed: $Date: 2008-02-26 17:36:59 +0100 (Tue, 26 Feb 2008) $</i>
<HR>
<P><a href="index.html">Main index</a> - <a href="raster.html">raster 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>
