<?xml version="1.0" encoding="UTF-8"?>
  <sect1 id="Miscellaneous_Functions">
	<title>Miscellaneous Functions</title>

	<refentry id="ST_Accum">
	  <refnamediv>
		<refname>ST_Accum</refname>

		<refpurpose>Aggregate. Constructs an array of geometries.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>geometry[] <function>ST_Accum</function></funcdef>
			<paramdef><type>geometry set</type> <parameter>geomfield</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>Aggregate. Constructs an array of geometries.</para>
		<para>Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.</para>
		<para>&Z_support;</para>
		<para>&curve_support;</para>
		<para>&P_support;</para>
		<para>&T_support;</para>
	  </refsection>


	  <refsection>
		<title>Examples</title>

		<programlisting>SELECT (ST_Accum(the_geom)) As all_em, ST_AsText((ST_Accum(the_geom))[1]) As grabone,
(ST_Accum(the_geom))[2:4] as grab_rest
			FROM (SELECT ST_MakePoint(a*CAST(random()*10 As integer), a*CAST(random()*10 As integer), a*CAST(random()*10 As integer)) As the_geom
				FROM generate_series(1,4) a) As foo;

all_em|grabone   | grab_rest

-------------------------------------------------------------------------------+

 {0101000080000000000000144000000000000024400000000000001040:
 0101000080000000000
00018400000000000002C400000000000003040:
0101000080000000000000354000000000000038400000000000001840:
010100008000000000000040400000000000003C400000000000003040} |
 POINT(5 10) | {010100008000000000000018400000000000002C400000000000003040:
 0101000080000000000000354000000000000038400000000000001840:
 010100008000000000000040400000000000003C400000000000003040}
(1 row)
		</programlisting>
	  </refsection>

	  <!-- Optionally add a "See Also" section -->
	  <refsection>
		<title>See Also</title>

		<para><xref linkend="ST_Collect" /></para>
	  </refsection>
	</refentry>

	<refentry id="Box2D">
	  <refnamediv>
		<refname>Box2D</refname>

		<refpurpose>Returns a BOX2D representing the maximum extents of the geometry.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>box2d <function>Box2D</function></funcdef>
			<paramdef><type>geometry </type> <parameter>geomA</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>Returns a BOX2D representing the maximum extents of the geometry.</para>

		<para>Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.</para>
		<para>&curve_support;</para>
		<para>&P_support;</para>
		<para>&T_support;</para>
	  </refsection>


	  <refsection>
		<title>Examples</title>

		<programlisting>SELECT Box2D(ST_GeomFromText('LINESTRING(1 2, 3 4, 5 6)'));
	box2d
	---------
	BOX(1 2,5 6)

	SELECT Box2D(ST_GeomFromText('CIRCULARSTRING(220268 150415,220227 150505,220227 150406)'));
	box2d
	--------
	BOX(220186.984375 150406,220288.25 150506.140625)
	</programlisting>
	  </refsection>

	  <!-- Optionally add a "See Also" section -->
	  <refsection>
		<title>See Also</title>

		<para><xref linkend="Box3D" />, <xref linkend="ST_GeomFromText" /></para>
	  </refsection>
	</refentry>

	<refentry id="Box3D">
	  <refnamediv>
		<refname>Box3D</refname>

		<refpurpose>Returns a BOX3D representing the maximum extents of the geometry.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>box3d <function>Box3D</function></funcdef>
			<paramdef><type>geometry </type> <parameter>geomA</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>Returns a BOX3D representing the maximum extents of the geometry.</para>
		<para>Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.</para>
		<para>&curve_support;</para>
		<para>&P_support;</para>
		<para>&T_support;</para>
		<para>&Z_support;</para>
	  </refsection>


	  <refsection>
		<title>Examples</title>

		<programlisting>SELECT Box3D(ST_GeomFromEWKT('LINESTRING(1 2 3, 3 4 5, 5 6 5)'));
	Box3d
	---------
	BOX3D(1 2 3,5 6 5)

	SELECT Box3D(ST_GeomFromEWKT('CIRCULARSTRING(220268 150415 1,220227 150505 1,220227 150406 1)'));
	Box3d
	--------
	BOX3D(220227 150406 1,220268 150415 1)
	</programlisting>
	  </refsection>

	  <!-- Optionally add a "See Also" section -->
	  <refsection>
		<title>See Also</title>

		<para><xref linkend="Box2D" />, <xref linkend="ST_GeomFromEWKT" /></para>
	  </refsection>
	</refentry>

	<refentry id="ST_EstimatedExtent">
	  <refnamediv>
		<refname>ST_EstimatedExtent</refname>

		<refpurpose>Return the 'estimated' extent of the given spatial table.
			The estimated is taken from the geometry column's statistics. The
			current schema will be used if not specified.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>box2d <function>ST_EstimatedExtent</function></funcdef>
			<paramdef><type>text </type> <parameter>schema_name</parameter></paramdef>
			<paramdef><type>text </type> <parameter>table_name</parameter></paramdef>
			<paramdef><type>text </type> <parameter>geocolumn_name</parameter></paramdef>
			<paramdef><type>boolean </type> <parameter>parent_ony</parameter></paramdef>
		  </funcprototype>


		  <funcprototype>
			<funcdef>box2d <function>ST_EstimatedExtent</function></funcdef>
			<paramdef><type>text </type> <parameter>schema_name</parameter></paramdef>
			<paramdef><type>text </type> <parameter>table_name</parameter></paramdef>
			<paramdef><type>text </type> <parameter>geocolumn_name</parameter></paramdef>
		  </funcprototype>

		  <funcprototype>
			<funcdef>box2d <function>ST_EstimatedExtent</function></funcdef>
			<paramdef><type>text </type> <parameter>table_name</parameter></paramdef>
			<paramdef><type>text </type> <parameter>geocolumn_name</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>Return the 'estimated' extent of the given spatial table.
			The estimated is taken from the geometry column's statistics. The
			current schema will be used if not specified. The default behavior
			is to also use statistics collected from children tables (tables
			with INHERITS) if available. If 'parent_ony' is set to TRUE, only
			statistics for the given table are used and children tables are
			ignored.
		</para>

		<para>For PostgreSQL&gt;=8.0.0 statistics are gathered by VACUUM
		ANALYZE and resulting extent will be about 95% of the real
		one.</para>

                <note>
                <para>
In absence of statistics (empty table or no ANALYZE called) this function
returns NULL.  Prior to version 1.5.4 an exception was thrown
instead.
		</para>
                </note>


		<para>For PostgreSQL&lt;8.0.0 statistics are gathered by
		update_geometry_stats() and resulting extent will be exact.</para>

    <para>Availability: 1.0.0</para>
    <para>Changed: 2.1.0. Up to 2.0.x this was called ST_Estimated_Extent.</para>

		<para>&curve_support;</para>
	  </refsection>


	  <refsection>
		<title>Examples</title>

		<programlisting>SELECT ST_EstimatedExtent('ny', 'edges', 'the_geom');
--result--
BOX(-8877653 4912316,-8010225.5 5589284)

SELECT ST_EstimatedExtent('feature_poly', 'the_geom');
--result--
BOX(-124.659652709961 24.6830825805664,-67.7798080444336 49.0012092590332)
		</programlisting>
	  </refsection>

	  <!-- Optionally add a "See Also" section -->
	  <refsection>
		<title>See Also</title>

		<para><xref linkend="ST_Extent" /></para>
	  </refsection>
	</refentry>
	<refentry id="ST_Expand">
	  <refnamediv>
		<refname>ST_Expand</refname>
		<refpurpose>Returns bounding box expanded in all directions from the bounding box of the input geometry. Uses double-precision</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>geometry <function>ST_Expand</function></funcdef>
			<paramdef><type>geometry </type> <parameter>geom</parameter></paramdef>
			<paramdef><type>float</type> <parameter>units_to_expand</parameter></paramdef>
		  </funcprototype>

		  <funcprototype>
			<funcdef>geometry <function>ST_Expand</function></funcdef>
			<paramdef><type>geometry </type> <parameter>geom</parameter></paramdef>
			<paramdef><type>float</type> <parameter>dx</parameter></paramdef>
			<paramdef><type>float</type> <parameter>dy</parameter></paramdef>
			<paramdef choice="opt"><type>float</type> <parameter>dz=0</parameter></paramdef>
			<paramdef choice="opt"><type>float</type> <parameter>dm=0</parameter></paramdef>
		  </funcprototype>

		  <funcprototype>
			<funcdef>box2d <function>ST_Expand</function></funcdef>
			<paramdef><type>box2d </type> <parameter>box</parameter></paramdef>
			<paramdef><type>float</type> <parameter>units_to_expand</parameter></paramdef>
		  </funcprototype>

		  <funcprototype>
			<funcdef>box2d <function>ST_Expand</function></funcdef>
			<paramdef><type>box2d </type> <parameter>box</parameter></paramdef>
			<paramdef><type>float</type> <parameter>dx</parameter></paramdef>
			<paramdef><type>float</type> <parameter>dy</parameter></paramdef>
		  </funcprototype>

		  <funcprototype>
			<funcdef>box3d <function>ST_Expand</function></funcdef>
			<paramdef><type>box3d </type> <parameter>box</parameter></paramdef>
			<paramdef><type>float</type> <parameter>units_to_expand</parameter></paramdef>
		  </funcprototype>

		  <funcprototype>
			<funcdef>box3d <function>ST_Expand</function></funcdef>
			<paramdef><type>box3d </type> <parameter>box</parameter></paramdef>
			<paramdef><type>float</type>  <parameter>dx</parameter></paramdef>
			<paramdef><type>float</type>  <parameter>dy</parameter></paramdef>
			<paramdef choice="opt"><type>float</type>  <parameter>dz=0</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>This function returns a bounding box expanded from the bounding box of the input,
			either by specifying a single distance with which the box should be expanded in all
			directions, or by specifying an expansion distance for each direction.

			Uses double-precision. Can be very useful for distance queries, or to add a bounding box
			filter to a query to take advantage of a spatial index.</para>
		<para>In addition to the geometry version of ST_Expand, which is the most commonly used, variants
			are provided that accept and produce internal BOX2D and BOX3D data types.
		</para>
		<para>ST_Expand is similar in concept to ST_Buffer, except while buffer expands the geometry in all directions,
			ST_Expand expands the bounding box an x,y,z unit amount.</para>
		<para>Units are in the units of the spatial reference system in use denoted by the SRID.</para>

		<note>
		  <para>Pre 1.3, ST_Expand was used in conjunction with distance to do indexable queries.  Something of the form
			<code>the_geom &amp;&amp; ST_Expand('POINT(10 20)', 10) AND ST_Distance(the_geom, 'POINT(10 20)') &lt; 10</code>
			Post 1.2, this was replaced with the easier ST_DWithin construct.</para>
		</note>

		<note>
			<para>Availability: 1.5.0 behavior changed to output double precision instead of float4 coordinates.</para>
			<para>Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.</para>
			<para>Enhanced: 2.3.0 support was added to expand a box by different amounts in different dimensions.</para>
		</note>

		<para>&P_support;</para>
		<para>&T_support;</para>

	  </refsection>

	  <refsection>
		<title>Examples</title>
		<note><para>Examples below use US National Atlas Equal Area (SRID=2163) which is a meter projection</para></note>
		<programlisting>
		<!-- TODO: fix results of documentation to reflect new behavior -->
--10 meter expanded box around bbox of a linestring
SELECT CAST(ST_Expand(ST_GeomFromText('LINESTRING(2312980 110676,2312923 110701,2312892 110714)', 2163),10) As box2d);
					 st_expand
------------------------------------
 BOX(2312882 110666,2312990 110724)

--10 meter expanded 3d box of a 3d box
SELECT ST_Expand(CAST('BOX3D(778783 2951741 1,794875 2970042.61545891 10)' As box3d),10)
							  st_expand
-----------------------------------------------------
 BOX3D(778773 2951731 -9,794885 2970052.61545891 20)

 --10 meter geometry astext rep of a expand box around a point geometry
 SELECT ST_AsEWKT(ST_Expand(ST_GeomFromEWKT('SRID=2163;POINT(2312980 110676)'),10));
											st_asewkt
-------------------------------------------------------------------------------------------------
 SRID=2163;POLYGON((2312970 110666,2312970 110686,2312990 110686,2312990 110666,2312970 110666))

		</programlisting>
	  </refsection>

	  <refsection>
		<title>See Also</title>
		<para><xref linkend="ST_AsEWKT" />, <xref linkend="ST_Buffer" />, <xref linkend="ST_DWithin" />, <xref linkend="ST_GeomFromEWKT" />, <xref linkend="ST_GeomFromText" />, <xref linkend="ST_SRID" /></para>
	  </refsection>
	</refentry>

	<refentry id="ST_Extent">
	  <refnamediv>
		<refname>ST_Extent</refname>
		<refpurpose>an aggregate function that returns the bounding box that bounds rows of geometries.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>box2d <function>ST_Extent</function></funcdef>
			<paramdef><type>geometry set</type> <parameter>geomfield</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>ST_Extent returns a bounding box that encloses a set of geometries. The ST_Extent function is an "aggregate" function in the
			terminology of SQL. That means that it operates on lists
			of data, in the same way the SUM() and AVG() functions do.</para>
		<para>Since it returns a bounding box, the spatial Units are in the units of the spatial reference system in use denoted by the SRID</para>
		<para>ST_Extent is similar in concept to Oracle Spatial/Locator's SDO_AGGR_MBR</para>
		<note>
		  <para>Since ST_Extent returns a bounding box, the SRID meta-data is lost.  Use ST_SetSRID to force it back into
			a geometry with SRID meta data.  The coordinates are in the units of the spatial ref of the orginal geometries.</para>
		</note>

		<note>
		  <para>ST_Extent will return boxes with only an x and y component even with (x,y,z) coordinate geometries.  To maintain x,y,z use ST_3DExtent instead.</para>
		</note>

		<note>
		  <para>Availability: 1.4.0</para>
		</note>

		<para>Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.</para>
		<para>&P_support;</para>
		<para>&T_support;</para>

	  </refsection>

	  <refsection>
		<title>Examples</title>
		<note><para>Examples below use Massachusetts State Plane ft (SRID=2249)</para></note>
		<programlisting>

SELECT ST_Extent(the_geom) as bextent FROM sometable;
					 st_bextent
------------------------------------
BOX(739651.875 2908247.25,794875.8125 2970042.75)


--Return extent of each category of geometries
SELECT ST_Extent(the_geom) as bextent
FROM sometable
GROUP BY category ORDER BY category;

					  bextent                       |         name
----------------------------------------------------+----------------
 BOX(778783.5625 2951741.25,794875.8125 2970042.75) | A
 BOX(751315.8125 2919164.75,765202.6875 2935417.25) | B
 BOX(739651.875 2917394.75,756688.375 2935866)      | C

 --Force back into a geometry
 -- and render the extended text representation of that geometry
SELECT ST_SetSRID(ST_Extent(the_geom),2249) as bextent FROM sometable;

				bextent
--------------------------------------------------------------------------------
 SRID=2249;POLYGON((739651.875 2908247.25,739651.875 2970042.75,794875.8125 2970042.75,
 794875.8125 2908247.25,739651.875 2908247.25))
		</programlisting>
	  </refsection>

	  <refsection>
		<title>See Also</title>
		<para><xref linkend="ST_AsEWKT" />, <xref linkend="ST_3DExtent" />, <xref linkend="ST_SetSRID" />, <xref linkend="ST_SRID" /></para>
	  </refsection>
	</refentry>

	<refentry id="ST_3DExtent">
	  <refnamediv>
		<refname>ST_3DExtent</refname>
		<refpurpose>an aggregate function that returns the box3D bounding box that bounds rows of geometries.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>box3d <function>ST_3DExtent</function></funcdef>
			<paramdef><type>geometry set</type> <parameter>geomfield</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>ST_3DExtent returns a box3d (includes Z coordinate) bounding box that encloses a set of geometries. The ST_3DExtent function is an "aggregate" function in the
			terminology of SQL. That means that it operates on lists
			of data, in the same way the SUM() and AVG() functions do.</para>
		<para>Since it returns a bounding box, the spatial Units are in the units of the spatial reference system in use denoted by the SRID</para>

		<note>
		  <para>Since ST_3DExtent returns a bounding box, the SRID meta-data is lost.  Use ST_SetSRID to force it back into
			a geometry with SRID meta data.  The coordinates are in the units of the spatial ref of the orginal geometries.</para>
		</note>

		<para>Enhanced: 2.0.0 support for Polyhedral surfaces, Triangles and TIN was introduced.</para>
		<para>Changed: 2.0.0 In prior versions this used to be called ST_Extent3D</para>
		<para>&Z_support;</para>
		<para>&curve_support;</para>
		<para>&P_support;</para>
		<para>&T_support;</para>
	  </refsection>

	  <refsection>
		<title>Examples</title>
		<programlisting>
SELECT ST_3DExtent(foo.the_geom) As b3extent
FROM (SELECT ST_MakePoint(x,y,z) As the_geom
	FROM generate_series(1,3) As x
		CROSS JOIN generate_series(1,2) As y
		CROSS JOIN generate_series(0,2) As Z) As foo;
	  b3extent
--------------------
 BOX3D(1 1 0,3 2 2)

--Get the extent of various elevated circular strings
SELECT ST_3DExtent(foo.the_geom) As b3extent
FROM (SELECT ST_Translate(ST_Force_3DZ(ST_LineToCurve(ST_Buffer(ST_MakePoint(x,y),1))),0,0,z) As the_geom
	FROM generate_series(1,3) As x
		CROSS JOIN generate_series(1,2) As y
		CROSS JOIN generate_series(0,2) As Z) As foo;

	b3extent
--------------------
 BOX3D(1 0 0,4 2 2)
		</programlisting>
	  </refsection>

	  <refsection>
		<title>See Also</title>
		<para><xref linkend="ST_Extent" />, <xref linkend="ST_Force_3DZ" /></para>
	  </refsection>
	</refentry>


	<refentry id="Find_SRID">
	  <refnamediv>
		<refname>Find_SRID</refname>

		<refpurpose>The syntax is find_srid(a_db_schema, a_table,
			a_column) and the function returns the integer SRID of the
			specified column by searching through the GEOMETRY_COLUMNS table.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>integer <function>Find_SRID</function></funcdef>
			<paramdef><type>varchar </type> <parameter>a_schema_name</parameter></paramdef>
			<paramdef><type>varchar </type> <parameter>a_table_name</parameter></paramdef>
			 <paramdef><type>varchar </type> <parameter>a_geomfield_name</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>The syntax is find_srid(&lt;db/schema&gt;, &lt;table&gt;,
			&lt;column&gt;) and the function returns the integer SRID of the
			specified column by searching through the GEOMETRY_COLUMNS table.
			If the geometry column has not been properly added with the
			AddGeometryColumns() function, this function will not work
			either.</para>
	  </refsection>


	  <refsection>
		<title>Examples</title>

		<programlisting> SELECT Find_SRID('public', 'tiger_us_state_2007', 'the_geom_4269');
find_srid
----------
4269
</programlisting>
	  </refsection>

	  <!-- Optionally add a "See Also" section -->
	  <refsection>
		<title>See Also</title>

		<para><xref linkend="ST_SRID" /></para>
	  </refsection>
	</refentry>

	<refentry id="ST_MemSize">
	  <refnamediv>
		<refname>ST_MemSize</refname>

		<refpurpose>Returns the amount of space (in bytes) the geometry takes.</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>integer <function>ST_MemSize</function></funcdef>
			<paramdef><type>geometry </type> <parameter>geomA</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>Returns the amount of space (in bytes) the geometry takes. </para>
		<para>This is a nice compliment to PostgreSQL built in functions pg_column_size, pg_size_pretty, pg_relation_size, pg_total_relation_size.</para>
		<note><para>pg_relation_size which gives the byte size of a table may return byte size lower than ST_MemSize. This is because
		pg_relation_size does not add toasted table contribution and large geometries are stored in TOAST tables.</para>
		<para>pg_total_relation_size - includes, the table, the toasted tables, and the indexes.</para>
		<para>pg_column_size returns how much space a geometry would take in a column considering compression, so may be lower than ST_MemSize</para>
		</note>

		<para>&Z_support;</para>
		<para>&curve_support;</para>
		<para>&P_support;</para>
		<para>&T_support;</para>
		<para>Changed: 2.2.0 name changed to ST_MemSize to follow naming convention.  In prior versions this function was called ST_Mem_Size, old name deprecated though still available.</para>
	  </refsection>


	  <refsection>
		<title>Examples</title>

		<programlisting>
--Return how much byte space Boston takes up  in our Mass data set
SELECT pg_size_pretty(SUM(ST_MemSize(the_geom))) as totgeomsum,
pg_size_pretty(SUM(CASE WHEN town = 'BOSTON' THEN ST_MemSize(the_geom) ELSE 0 END)) As bossum,
CAST(SUM(CASE WHEN town = 'BOSTON' THEN ST_MemSize(the_geom) ELSE 0 END)*1.00 /
		SUM(ST_MemSize(the_geom))*100 As numeric(10,2)) As perbos
FROM towns;

totgeomsum	bossum	perbos
----------	------	------
1522 kB		30 kB	1.99


SELECT ST_MemSize(ST_GeomFromText('CIRCULARSTRING(220268 150415,220227 150505,220227 150406)'));

---
73

--What percentage of our table is taken up by just the geometry
SELECT pg_total_relation_size('public.neighborhoods') As fulltable_size, sum(ST_MemSize(the_geom)) As geomsize,
sum(ST_MemSize(the_geom))*1.00/pg_total_relation_size('public.neighborhoods')*100 As pergeom
FROM neighborhoods;
fulltable_size geomsize  pergeom
------------------------------------------------
262144         96238	 36.71188354492187500000
	</programlisting>
	  </refsection>

	  <!-- Optionally add a "See Also" section -->
	  <refsection>
		<title>See Also</title>

		<para></para>
	  </refsection>
	</refentry>

	<refentry id="ST_Point_Inside_Circle">
	  <refnamediv>
		<refname>ST_PointInsideCircle</refname>

		<refpurpose>Is the point geometry inside the circle defined by center_x, center_y, radius</refpurpose>
	  </refnamediv>

	  <refsynopsisdiv>
		<funcsynopsis>
		  <funcprototype>
			<funcdef>boolean <function>ST_PointInsideCircle</function></funcdef>
			<paramdef><type>geometry </type> <parameter>a_point</parameter></paramdef>
			<paramdef><type>float </type> <parameter>center_x</parameter></paramdef>
			<paramdef><type>float </type> <parameter>center_y</parameter></paramdef>
			<paramdef><type>float </type> <parameter>radius</parameter></paramdef>
		  </funcprototype>
		</funcsynopsis>
	  </refsynopsisdiv>

	  <refsection>
		<title>Description</title>

		<para>The syntax for this functions is
			ST_PointInsideCircle(&lt;geometry&gt;,&lt;circle_center_x&gt;,&lt;circle_center_y&gt;,&lt;radius&gt;).
			Returns the true if the geometry is a point and is inside the
			circle. Returns false otherwise.</para>
		<note><para>This only works for points as the name suggests</para></note>

		<para>Availability: 1.2</para>
		<para>Changed: 2.2.0 In prior versions this used to be called ST_Point_Inside_Circle</para>
	  </refsection>


	  <refsection>
		<title>Examples</title>

		<programlisting>SELECT ST_PointInsideCircle(ST_Point(1,2), 0.5, 2, 3);
 st_pointinsidecircle
------------------------
 t
</programlisting>
	  </refsection>

	  <!-- Optionally add a "See Also" section -->
	  <refsection>
		<title>See Also</title>

		<para><xref linkend="ST_DWithin" /></para>
	  </refsection>
	</refentry>


 </sect1>