v.rmarea.html

<h2>DESCRIPTION</h2>

<em>v.rmarea</em> removes small areas similar to <em><a href="v.clean.html">v.clean</a></em>. 
The main difference is that small areas are merged with a neighboring area 
with identical attributes in the specified <em>columns</em>. 
An error map is optionally written which stores the erroneous
geometries.


<h3>Remove small areas</h3>
<em>tool=rmarea</em>
<p>
The <em>rmarea</em> tool attempts to remove areas &lt;= <em>thresh</em>. The
longest boundary with an adjacent area with identical attributes is removed. 
If there is no adjacent area with identical attributes, the area is left unchanged,
even if it is smaller than <em>thresh</em>.
<p>
Threshold must always be in square meters, also for latitude-longitude
projects or projects with units other than meters.

<h2>NOTES</h2>

The user does <b>not</b> have to run <em><a href="v.build.html">v.build</a></em>
on the <em>output</em> vector, unless the <em>-b</em> flag was used. The
<em>-b</em> flag affects <b>only</b> the <em>output</em> vector -
topology is always built for <em>error</em> vector.

<h2>EXAMPLES</h2>

<h3>Remove areas smaller than 10 m<sup>2</sup></h3>
<div class="code"><pre>
v.rmarea input=testmap output=cleanmap threshold=10 columns=label
</pre></div>

<h2>SEE ALSO</h2>

<em>
<a href="v.clean.html">v.clean</a>,
<a href="v.info.html">v.info</a>,
<a href="v.build.html">v.build</a>,
<a href="g.gui.vdigit.html">g.gui.vdigit</a>,
<a href="v.edit.html">v.edit</a>,
<a href="v.fill.holes.html">v.fill.holes</a>,
<a href="v.generalize.html">v.generalize</a>
</em>

<h2>AUTHORS</h2>

David Gerdes, U.S. Army Construction Engineering Research Laboratory<br>
Radim Blazek, ITC-irst, Trento, Italy<br>
Martin Landa, FBK-irst (formerly ITC-irst), Trento, Italy<br>
Markus Metz, mundialis