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<h2>NAME</h2>
<em><b>r3.cross.rast</b></em> - Creates cross section 2D raster map from 3d raster map based on 2D elevation map
<h2>KEYWORDS</h2>
raster3d, voxel
<h2>SYNOPSIS</h2>
<b>r3.cross.rast</b><br>
<b>r3.cross.rast help</b><br>
<b>r3.cross.rast</b> [-<b>m</b>] <b>input</b>=<em>string</em> <b>elevation</b>=<em>string</em> <b>output</b>=<em>string</em> [--<b>overwrite</b>] [--<b>verbose</b>] [--<b>quiet</b>]
<h3>Flags:</h3>
<DL>
<DT><b>-m</b></DT>
<DD>Use g3d mask (if exists) with input map</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>string</em></DT>
<DD>Input 3D raster map for cross section.</DD>
<DT><b>elevation</b>=<em>string</em></DT>
<DD>2D elevation map used to create the cross section map</DD>
<DT><b>output</b>=<em>string</em></DT>
<DD>Resulting cross section 2D raster map</DD>
</DL>
<H2>DESCRIPTION</H2>
This module creates a cross section 2D map from one g3d raster volume
map based on a 2D elevation map. It checks if the value of the
elevation map is located in the z-coordinate space of the 3d map. If
so, the 3D voxel value for this position is transferred to the related
cross section output map cell, otherwise the NULL value is set.
<center>
<img src=r3.cross.rast.png border=0><BR>
<table border=0 width=700>
<tr><td><center>
<i>How r3.cross.rast works</i>
</center></td></tr>
</table>
</center>
<br>
<br>
If the 2d and 3d region settings are different,
the 2d resolution will be adjust to the 3d resolution.
<H2>NOTES</H2>
To create a cut plane elevation map use <em>r.mapcalc</em>. Some examples:
<ul>
<li>To create a cut plane elevation map in x direction type
<br><i>r.mapcalc "cutplane = col()*x"</i>,<br> x be the value for
the elevation. If the range of col() is 1 ... 10, the elevation map
has the range 1 ... 10 if x == 1 and if x == 10 the range 10
... 100</li>
<li>To create a cut plane elevation map in y direction type
<br><i>r.mapcalc "cutplane = row()*x"</i>,<br> x be the value for
the elevation. If the range of col() is 1 ... 10, the elevation map
has the range 1 ... 10 if x == 1 and if x == 10 the range 10
... 100</li>
<li>The user can also make a cut in y and x direction with <em>r.mapcalc</em> by
using <br><i>r.mapcalc "cutplane = (row()+col())*x"</i></li>
</ul>
<H2>EXAMPLE</H2>
<H3>Simple Spearfish example</H3>
<div class="code"><pre>
g.region -d
g.region res=150 res3=150 t=1000 b=0 tbres=100
# synthetic data, could be geological structures:
r3.mapcalc "map3d=sin(row())+sin(col())+sin(depth()*depth())"
#create a cutplane map
r.mapcalc "cutplane = col()*10"
#create the cross section map
r3.cross.rast input=map3d elevation=cutplane output=crosssection
</pre></div>
<H2>SEE ALSO</H2>
<EM><A HREF="g.region.html">g.region</A></EM><br>
<EM><A HREF="r.mapcalc.html">r.mapcalc</A></EM><br>
<EM><A HREF="r3.mapcalc.html">r3.mapcalc</A></EM><br>
<EM><A HREF="r3.to.rast.html">r3.to.rast</A></EM><br>
<H2>AUTHOR</H2>
Soeren Gebbert
<p><i>Last changed: $Date: 2006-07-10 20:11:49 +0200 (Mon, 10 Jul 2006) $</i>
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