[GRASS-SVN] r52827 - grass/branches/releasebranch_6_4/vector/v.in.ogr

[svn_grass at osgeo.org]

Author: neteler
Date: 2012-08-21 12:23:56 -0700 (Tue, 21 Aug 2012)
New Revision: 52827

Modified:
   grass/branches/releasebranch_6_4/vector/v.in.ogr/description.html
Log:
docs backport of trunk r52825 + older addition

Modified: grass/branches/releasebranch_6_4/vector/v.in.ogr/description.html
===================================================================
--- grass/branches/releasebranch_6_4/vector/v.in.ogr/description.html	2012-08-21 19:04:19 UTC (rev 52826)
+++ grass/branches/releasebranch_6_4/vector/v.in.ogr/description.html	2012-08-21 19:23:56 UTC (rev 52827)
@@ -24,6 +24,11 @@
 The <b>min_area</b> threshold value is being specified as area size
 in map units with the exception of latitude-longitude locations in which
 it is being specified solely in square meters.
+<p>
+The <b>snap</b> threshold value is used to snap boundary vertices to 
+each other if the distance in map units between two vertices is not 
+larger than the threshold. Snapping is by default disabled with -1. See 
+also the <a href="v.clean.html">v.clean</a> manual.
 
 <h3>Supported OGR Vector Formats</h3>
 
@@ -37,6 +42,17 @@
 installation (OGR library), for details see
 <a href="http://www.gdal.org/ogr/ogr_formats.html">OGR web site</a>.
 
+<h3>Overlapping polygons</h3>
+When importing overlapping polygons, the overlapping parts will become 
+new areas with multiple categories, one unique category for each original 
+polygon. An original polygon will thus be converted to multiple areas 
+with the same shared category. These multiple areas will therefore also 
+link to the same entry in the attribute table. A single category value 
+may thus refer to multiple non-overlapping areas which together represent 
+the original polygon overlapping with another polygon. The original 
+polygon can be recovered by using <em>v.extract</em> with the desired 
+category value or <em>where</em> statement and the <em>-d</em> flag to 
+dissolve common boundaries.
 
 <h2>Location Creation</h2>
 
@@ -218,6 +234,7 @@
 <em>
 <a href="db.connect.html">db.connect</a>,
 <a href="v.clean.html">v.clean</a>,
+<a href="v.extract.html">v.extract</a>,
 <a href="v.build.polylines.html">v.build.polylines</a>,
 <a href="v.edit.html">v.edit</a>,
 <a href="v.external.html">v.external</a>,