#1929 document behavior change and speed improvements

git-svn-id: http://svn.osgeo.org/postgis/trunk@10086 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference_raster.xml b/doc/reference_raster.xml
index e4bc0b455f74fb07ee8e1ca513ecdc16161e5b6a..1f550af1b18ebe308fb8617baa6747397aeeadce 100644 (file)
--- a/doc/reference_raster.xml
+++ b/doc/reference_raster.xml
@@ -7848,7 +7848,7 @@ SELECT ST_MapAlgebraFctNgb(rast, 1,  '8BUI', 4,4,
                <refentry id="RT_ST_Polygon">
                  <refnamediv>
                        <refname>ST_Polygon</refname>
-                       <refpurpose>Returns a polygon geometry formed by the union of pixels that have a pixel value that is not no data value.  If no band number is specified, band num defaults to 1.</refpurpose>
+                       <refpurpose>Returns a multipolygon geometry formed by the union of pixels that have a pixel value that is not no data value.  If no band number is specified, band num defaults to 1.</refpurpose>
                  </refnamediv>
        
                  <refsynopsisdiv>
@@ -7864,22 +7864,21 @@ SELECT ST_MapAlgebraFctNgb(rast, 1,  '8BUI', 4,4,
        
                  <refsection>
                        <title>Description</title>
-                               <para>Availability: Requires GDAL 1.7 or higher.</para>
+                               <para>Availability: 0.1.6 Requires GDAL 1.7 or higher.</para>
+                               <para>Enhanced: 2.1.0 Improved Speed (fully C-Based)</para>
+                               <para>Changed: 2.1.0 In prior versions would sometimes return a polygon, changed to always return multipolygon</para>
                  </refsection>
        
                  <refsection>
                        <title>Examples</title>
-                       <programlisting>
--- by default no data band value is 0 or not set, so polygon will return a square polygon      
+                       <programlisting>-- by default no data band value is 0 or not set, so polygon will return a square polygon       
 SELECT ST_AsText(ST_Polygon(rast)) As geomwkt
 FROM dummy_rast
 WHERE rid = 2;
 
 geomwkt
 --------------------------------------------
-POLYGON((3427927.8 5793243.75,3427927.75 5793243.75,3427927.75 5793243.8,3427927.75 5793243.85,3427927.75 5793243.9,
-3427927.75 5793244,3427927.8 5793244,3427927.85 5793244,3427927.9 5793244,3427928 5793244,3427928 5793243.95,
-3427928 5793243.85,3427928 5793243.8,3427928 5793243.75,3427927.85 5793243.75,3427927.8 5793243.75))
+MULTIPOLYGON(((3427927.75 5793244,3427928 5793244,3427928 5793243.75,3427927.75 5793243.75,3427927.75 5793244)))
                
                
 -- now we change the no data value of first band
@@ -7895,10 +7894,7 @@ WHERE rid = 2;
 
 geomwkt
 ---------------------------------------------------------
-MULTIPOLYGON(((3427927.9 5793243.95,3427927.85 5793243.95,3427927.85 5793244,3427927.9 5793244,3427927.9 5793243.95)),
-((3427928 5793243.85,3427928 5793243.8,3427927.95 5793243.8,3427927.95 5793243.85,3427927.9 5793243.85,3427927.9 5793243.9,3427927.9 5793243.95,3427927.95 5793243.95,3427928 5793243.95,3427928 5793243.85)),
-((3427927.8 5793243.75,3427927.75 5793243.75,3427927.75 5793243.8,3427927.75 5793243.85,3427927.75 5793243.9,3427927.75 5793244,3427927.8 5793244,
-3427927.8 5793243.9,3427927.8 5793243.85,3427927.85 5793243.85,3427927.85 5793243.8,3427927.85 5793243.75,3427927.8 5793243.75)))
+MULTIPOLYGON(((3427927.9 5793243.95,3427927.85 5793243.95,3427927.85 5793244,3427927.9 5793244,3427927.9 5793243.95)),((3427928 5793243.85,3427928 5793243.8,3427927.95 5793243.8,3427927.95 5793243.85,3427927.9 5793243.85,3427927.9 5793243.9,3427927.9 5793243.95,3427927.95 5793243.95,3427928 5793243.95,3427928 5793243.85)),((3427927.8 5793243.75,3427927.75 5793243.75,3427927.75 5793243.8,3427927.75 5793243.85,3427927.75 5793243.9,3427927.75 5793244,3427927.8 5793244,3427927.8 5793243.9,3427927.8 5793243.85,3427927.85 5793243.85,3427927.85 5793243.8,3427927.85 5793243.75,3427927.8 5793243.75)))
 
 -- Or if you want the no data value different for just one time
 
@@ -7912,11 +7908,7 @@ WHERE rid =2;
 
 geomwkt
 ---------------------------------
-POLYGON((3427928 5793243.85,3427928 5793243.8,3427928 5793243.75,3427927.85 5793243.75,3427927.8 5793243.75,3427927.8 5793243.8,3427927.75 5793243.8,3427927.75 5793243.85,3427927.75 5793243.9,3427927.75 5793244,3427927.8 5793244,3427927.85 5793244,3427927.9 5793244,3427928 5793244,3427928 5793243.95,3427928 5793243.85),
-(3427927.9 5793243.9,3427927.9 5793243.85,3427927.95 5793243.85,3427927.95 5793243.9,3427927.9 5793243.9))
-
-
-                       </programlisting>
+MULTIPOLYGON(((3427928 5793243.85,3427928 5793243.8,3427928 5793243.75,3427927.85 5793243.75,3427927.8 5793243.75,3427927.8 5793243.8,3427927.75 5793243.8,3427927.75 5793243.85,3427927.75 5793243.9,3427927.75 5793244,3427927.8 5793244,3427927.85 5793244,3427927.9 5793244,3427928 5793244,3427928 5793243.95,3427928 5793243.85),(3427927.9 5793243.9,3427927.9 5793243.85,3427927.95 5793243.85,3427927.95 5793243.9,3427927.9 5793243.9)))</programlisting>
                  </refsection>
                  <refsection>
                        <title>See Also</title>