[GRASS-SVN] r39565 - grass/trunk/vector

[svn_grass at osgeo.org]

Author: mmetz
Date: 2009-10-18 11:59:59 -0400 (Sun, 18 Oct 2009)
New Revision: 39565

Modified:
   grass/trunk/vector/vectorintro.html
Log:
vector intro updated for trunk

Modified: grass/trunk/vector/vectorintro.html
===================================================================
--- grass/trunk/vector/vectorintro.html	2009-10-18 15:59:35 UTC (rev 39564)
+++ grass/trunk/vector/vectorintro.html	2009-10-18 15:59:59 UTC (rev 39565)
@@ -93,8 +93,8 @@
 <li> point: a point; </li>
 <li> line: a directed sequence of connected vertices with two endpoints called nodes; </li>
 <li> boundary: the border line to describe an area; </li>
-<li> centroid: a point within a closed boundary; </li>
-<li> area: the topological composition of centroid and boundary; </li>
+<li> centroid: a point within a closed ring of boundaries; </li>
+<li> area: the topological composition of a closed ring of boundaries and optionally a centroid; </li>
 <li> face: a 3D area; </li>
 <li> kernel: a 3D centroid in a volume (not yet implemented); </li>
 <li> volume: a 3D corpus, the topological composition of faces and kernel (not yet implemented). </li>
@@ -102,10 +102,10 @@
 <p>
 Note that all lines and boundaries can be polylines (with nodes in between).
 <p>
-Topology also holds information about isles. Isles are located within an
-area, not touching the boundaries of the outer area. Isles consist of
-one or more areas and are used internally to maintain correct topology
-for areas.
+Area topology also holds information about isles. These isles are located
+within that area, not touching the boundaries of the outer area. Isles
+consist of one or more areas and are used internally to maintain correct
+topology for areas.
 
 <P>
 The <a href="v.type.html">v.type</a> module can be used to convert
@@ -126,7 +126,7 @@
 Many operations including extraction, queries, overlay, and export will
 only act on features which have been assigned a category number. Typically
 a centroid will hold the attribute data for the area between it and its
-boundary. Boundaries are not typically given a category ID as it would be
+boundaries. Boundaries are not typically given a category ID as it would be
 ambiguous as to which area either side of it the attribute data would belong
 to. An exception might be when the boundary between two crop-fields is the
 center-line of a road, and the category information is an index to the road