document histogram type

git-svn-id: http://svn.osgeo.org/postgis/trunk@7328 b70326c6-7e19-0410-871a-916f4a2858ee

diff --git a/doc/reference_raster.xml b/doc/reference_raster.xml
index 64068e6c737a613bbf20c1e7ca690d8deceb0fd9..a103760597deb053eeb3f09662f8947a1af290d3 100644 (file)
--- a/doc/reference_raster.xml
+++ b/doc/reference_raster.xml
@@ -288,6 +288,37 @@ VALUES (1,
             </refsection>
                </refentry>
                
+               <refentry id="histogram">
+                 <refnamediv>
+                       <refname>histogram</refname>
+                       <refpurpose>A composite type used as record output of the ST_Histogram and ST_ApproxHistogram functions. </refpurpose>
+                 </refnamediv>
+                 <refsection>
+                       <title>Description</title>
+                       <para>A composite type used as record outputs of the <xref linkend="RT_ST_Histogram" /><varname>ST_ApproxHistogram</varname> functions. Note that depending on <varname>exclude_nodata_value</varname> of function, may or may not contain nodata pixels.</para>
+                       <para>Each histogram record in results corresponds to a bin for a selected raster band.</para>
+                       <variablelist>
+                           <varlistentry>
+                               <term><parameter>min </parameter><type>double precision</type></term>
+                               <listitem><para>minimum pixel value in this bin</para></listitem>
+                           </varlistentry>
+                           <varlistentry>
+                               <term><parameter>max </parameter><type>double precision</type></term>
+                               <listitem><para>Maximum pixel value in this bin.</para></listitem>
+                           </varlistentry>
+                               <varlistentry>
+                               <term><parameter>count </parameter><type>integer</type></term>
+                               <listitem><para>count of pixels in this bin.</para></listitem>
+                           </varlistentry>
+                        
+                       </variablelist>
+                 </refsection>
+                  <refsection>
+                <title>See Also</title>
+                <para><xref linkend="RT_ST_Histogram" /></para>
+           </refsection>
+               </refentry>
+               
                <refentry id="raster">
             <refnamediv>
                 <refname>raster</refname>
@@ -3530,7 +3561,7 @@ FROM (SELECT rid, ST_Histogram(rast, 2,6,ARRAY[0.5,1,4,100,5]) As stats
 
                        <refsection>
                                <title>See Also</title>
-                               <para><xref linkend="RT_ST_Count" />, <xref linkend="RT_ST_SummaryStats" /></para>
+                               <para><xref linkend="histogram" />, <xref linkend="RT_ST_Count" />, <xref linkend="RT_ST_SummaryStats" /></para>
                        </refsection>
                </refentry>