Geografic-Information-System/vector/v.lrs/v.lrs.segment/v.lrs.segment.html

<h2>DESCRIPTION</h2>

<em>v.lrs.segment</em> creates points/segments from input lines,
linear reference system and positions read from <tt>standard in</tt>
or a file.
<p>
The format is as follows:<br>

<div class="code"><pre>
P &lt;point_id&gt; &lt;line_id&gt; &lt;milepost&gt;+&lt;offset&gt; [&lt;side offset&gt;]
L &lt;segment_id&gt; &lt;line_id&gt; &lt;milepost&gt;+&lt;offset&gt; &lt;milepost&gt;+&lt;offset&gt; [&lt;side offset&gt;]
</pre></div>

<h2>NOTES</h2>

For more information and examples see the help page for <em>v.lrs.segment</em>'s
sister module, <em><a href="v.segment.html">v.segment</a></em>.

<h2>EXAMPLE</h2>

This example is written for the Spearfish dataset (it continues the example
from <em>v.lrs.create</em>).
<p>
In this example, the 'route_lrs' shall be extended for a new
position (point) along the LRS after bus stop 4:

<div class="code"><pre>
# new point on LRS
echo "P 7 22 4+180" | v.lrs.segment route_lrs out=route_lrs_new rstable=route_lrs

g.region vector=route_lrs n=n+100 s=s-100 -p
d.erase
# existing LRS
d.vect route_lrs
d.vect busstops disp=attr attr=cat size=10 bg=white lcol=blue yref=bottom
d.vect busstops icon=basic/circle fcol=blue
db.select table=route_lrs

# show modified map
d.vect route_lrs_new col=red
</pre></div>

<h2>TODO</h2>

Figure out how to merge result into existing LRS map and table.

<h2>SEE ALSO</h2>

<em>
<a href="lrs.html">LRS tutorial</a>,<br>
<a href="http://gisws.media.osaka-cu.ac.jp/grass04/viewpaper.php?id=50">Introducing the Linear Reference System in GRASS</a>,<br>
<a href="v.lrs.create.html">v.lrs.create</a>,
<a href="v.lrs.where.html">v.lrs.where</a>,
<a href="v.lrs.label.html">v.lrs.label</a>,
<a href="v.segment.html">v.segment</a>
</em>

<h2>AUTHOR</h2>

Radim Blazek

<p>
<i>Last changed: $Date$</i>