[GRASS-SVN] r40370 - grass-addons/vector/v.in.mbsys_fnv

[svn_grass at osgeo.org]

Author: hamish
Date: 2010-01-11 01:28:33 -0500 (Mon, 11 Jan 2010)
New Revision: 40370

Modified:
   grass-addons/vector/v.in.mbsys_fnv/description.html
Log:
updates

Modified: grass-addons/vector/v.in.mbsys_fnv/description.html
===================================================================
--- grass-addons/vector/v.in.mbsys_fnv/description.html	2010-01-11 00:41:03 UTC (rev 40369)
+++ grass-addons/vector/v.in.mbsys_fnv/description.html	2010-01-11 06:28:33 UTC (rev 40370)
@@ -11,21 +11,34 @@
 Geodesic line length/swath width (in meters) is provided for the <i>track</i>
 line and <i>scanline</i> types, and geodesic area (in square meters) is given
 for the swath coverage type.
+
 <P>
 The databases for <i>port_trk</i> and <i>stbd_trk</i> line maps contain
 the ship's <i>center track line</i> lat/lon starting and ending position,
 not the starting and ending position of the outward beams. Positions
 for the start and end points of the outward beams are encoded in the
 map data and may be extracted with e.g. the <em>v.to.db</em> module.
+
 <P>
+The <em>v.patch</em> module can be used to group many scan lines together
+into the same map. See the GRASS
+ <a href="http://grass.osgeo.org/wiki/MB-System">MB-System wiki page</a>
+for details and many examples.
+<BR>
 If you want to patch the tracks together later it is suggested to extract
 some sort of integer from the input filename to set as the category
 number. GRASS vector maps must have SQL compliant names, i.e. they
 may not start with a number or contain characters such as "." or "-".
 
+<P>
+If attributes for all maps are stored in a central database, for example
+<a href="grass-sqlite.html">SQLite</a> or <a href="grass-pg.html">Postgres</a>,
+an assortment of SQL database queries can be made.
 
-<H2>EXAMPLE</H2>
 
+
+<H2>EXAMPLES</H2>
+
 Here is a loop to read in all the maps listed in the
 <tt>datalist-1</tt> file and import tracks and swath coverages for them.
 Category is simply left as an incrementing number as naming schemes will
@@ -56,14 +69,38 @@
 </pre></div>
 
 
-The <em>v.patch</em> module can be used to group many scan lines together
-into the same map:
+<h4>SQL queries</h4>
+After maps are imported SQL queries may be performed on a unified
+database (for example SQLite or Postgres).
+<P>
+Find all track files within a given bounding box on julain day 261
+with a track length shorter than 500 meters:
+
 <div class="code"><pre>
-v.patch -e in=`g.mlist type=vect pattern=trk_* sep=,` out=all_tracks \
-   bbox=all_tracks_bbox
+echo "SELECT filename  FROM datalist_tracks \
+   WHERE length_m < 500 AND julian_day = 261 AND \
+   bbox_north <= 40.4 AND bbox_south > 40.3 AND \
+   bbox_west > -73.75 AND bbox_east <= -73.5" | db.select
 </pre></div>
 
+<!--
+<div class="code"><pre>
+echo "SUM(length_m) FROM datalist_tracks \
+  WHERE julian_day = 116" | db.execute
+</pre></div>
+-->
 
+Find tracks shorter than 500m from a combined <em>v.patch</em>
+vector map:
+<div class="code"><pre>
+db.select sql="SELECT length_m, filename, start_time \
+  FROM datalist_tracks WHERE length_m < 500"
+</pre></div>
+
+
+
+
+
 <H2>SEE ALSO</H2>
 <em>
 <A HREF="v.in.ascii.html">v.in.ascii</A><br>
@@ -73,6 +110,8 @@
 <A HREF="v.to.db.html">v.to.db</A>
 </em>
 <BR><BR>
+The <a href="http://grass.osgeo.org/wiki/MB-System">MB-System page</a>
+ on the GRASS wiki site<BR>
 <a href="http://www.ldeo.columbia.edu/res/pi/MB-System/">MB-System</a>
  software for multibeam and sidescan sonar processing