[postgis-tickets] r16093 - Documentation tweaks for st_voronoi from Anne Blankert

[Paul Ramsey]

Author: pramsey
Date: 2017-11-06 13:51:27 -0800 (Mon, 06 Nov 2017)
New Revision: 16093

Modified:
   trunk/doc/reference_processing.xml
Log:
Documentation tweaks for st_voronoi from Anne Blankert


Modified: trunk/doc/reference_processing.xml
===================================================================
--- trunk/doc/reference_processing.xml	2017-11-06 19:18:30 UTC (rev 16092)
+++ trunk/doc/reference_processing.xml	2017-11-06 21:51:27 UTC (rev 16093)
@@ -3709,24 +3709,22 @@
 
 	  <refsection>
 		<title>Description</title>
-
 		<para>
 			ST_VoronoiLines computes a two-dimensional <ulink url="https://en.wikipedia.org/wiki/Voronoi_diagram">Voronoi diagram</ulink> from the vertices of
-            the supplied geometry and returns the boundaries between cells in that diagram as a MultiLineString.
-        </para>
-
+			the supplied geometry and returns the boundaries between cells in that diagram as a MultiLineString.
+			Returns null if input geometry is null. Returns an empty geometry collection if the input geometry contains only one vertex. Returns an empty geometry collection if the extend_to envelope has zero area.
+		</para>
 		<para>
 			Optional parameters:
-		<itemizedlist>
-			<listitem>
-                <para> 'tolerance' : The distance within which vertices will be considered equivalent.  Robustness of the algorithm can be improved by supplying a nonzero tolerance distance.  (default = 0.0)</para>
-			</listitem>
-			<listitem>
-				<para>'extend_to' : If a geometry is supplied as the "extend_to" parameter, the diagram will be extended to cover the
-					envelope of the "extend_to" geometry, unless that envelope is smaller than the default envelope.
-					(default = NULL)</para>
-			</listitem>
-		</itemizedlist>
+			<itemizedlist>
+				<listitem>
+					<para> 'tolerance' : The distance within which vertices will be considered equivalent.  Robustness of the algorithm can be improved by supplying a nonzero tolerance distance.  (default = 0.0)</para>
+				</listitem>
+				<listitem>
+					<para>'extend_to' : If a geometry is supplied as the "extend_to" parameter, the diagram will be extended to cover the envelope of the "extend_to" geometry, unless
+						that envelope is smaller than the default envelope (default = NULL, default envelope is boundingbox of input geometry extended by about 50% in each direction).</para>
+				</listitem>
+			</itemizedlist>
 		</para>
 
 		<para>Availability: 2.3.0 - requires GEOS >= 3.5.0.</para>
@@ -3806,20 +3804,21 @@
 		<para>
 			ST_VoronoiPolygons computes a two-dimensional <ulink url="https://en.wikipedia.org/wiki/Voronoi_diagram">Voronoi diagram</ulink> from the vertices of
 			the supplied geometry.  The result is a GeometryCollection of Polygons that covers an envelope larger than the extent of the input vertices.
+			Returns null if input geometry is null. Returns an empty geometry collection if the input geometry contains only one vertex. Returns an empty geometry collection if the extend_to envelope has zero area.
 		</para>
 
 		<para>
 			Optional parameters:
-		<itemizedlist>
-			<listitem>
-			<para>'tolerance' : The distance within which vertices will be considered equivalent.  Robustness of the algorithm can be improved by supplying a nonzero tolerance distance.  (default = 0.0)</para>
-			</listitem>
-			<listitem>
-				<para>'extend_to' : If a geometry is supplied as the "extend_to" parameter, the diagram will be extended to cover the
-					envelope of the "extend_to" geometry, unless that envelope is smaller than the default envelope.
-					(default = NULL)</para>
-			</listitem>
-		</itemizedlist>
+			<itemizedlist>
+				<listitem>
+					<para> 'tolerance' : The distance within which vertices will be considered equivalent.  Robustness of the algorithm can be improved by supplying a nonzero tolerance distance.  (default = 0.0)</para>
+				</listitem>
+				<listitem>
+					<para>'extend_to' : If a geometry is supplied as the "extend_to" parameter, the diagram will be extended to cover the envelope of the "extend_to" geometry, unless
+						that envelope is smaller than the default envelope (default = NULL, default envelope is boundingbox of input geometry extended by about 50% in each direction).
+					</para>
+				</listitem>
+			</itemizedlist>
 		</para>
 
 		<para>Availability: 2.3.0 - requires GEOS >= 3.5.0.</para>