</listitem>
</varlistentry>
- <varlistentry>
- <term>ST_PointOnSurface(geometry)</term>
-
- <listitem>
- <para>Return a Point guaranteed to lie on the surface</para>
-
- <para>Implemented using GEOS</para>
-
- <para>OGC SPEC 3.2.14.2 and 3.2.18.2 -</para>
- </listitem>
- </varlistentry>
-
<varlistentry>
<term>ST_Boundary(geometry)</term>
</listitem>
</varlistentry>
- <varlistentry>
+ <varlistentry id="ST_Point_Inside_Circle">
<term>ST_point_inside_circle(geometry, float, float, float)</term>
<listitem>
</listitem>
</varlistentry>
- <varlistentry id="ST_PointOnSurface">
- <term>ST_PointOnSurface</term>
-
- <listitem>
- <para>Return an ST_Point value guaranteed to spatially intersect the
- ST_Surface or ST_MultiSurface value.</para>
-
- <para>SQL-MM 3: 8.1.5, 9.5.6</para>
- </listitem>
- </varlistentry>
-
<varlistentry>
<term>ST_PolyFromText</term>
</refsection>
</refentry>
+ <refentry id="ST_PointOnSurface">
+ <refnamediv>
+ <refname>ST_PointOnSurface</refname>
+
+ <refpurpose>Returns a <varname>POINT</varname> guaranteed to lie on the surface.</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcprototype>
+ <funcdef>boolean <function>ST_PointOnSurface</function></funcdef>
+
+ <paramdef><type>geometry </type>
+ <parameter>g1</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsection>
+ <title>Description</title>
+
+ <para>Returns a <varname>POINT</varname> guaranteed to intersect a surface.</para>
+
+ <para><inlinemediaobject>
+ <imageobject>
+ <imagedata fileref="images/check.png" />
+ </imageobject>
+ </inlinemediaobject> This method implements the <ulink
+ url="http://www.opengeospatial.org/standards/sfs">OpenGIS Simple
+ Features Implementation Specification for SQL: 3.2.14.2, 3.2.18.2</ulink></para>
+
+ <para><inlinemediaobject>
+ <imageobject>
+ <imagedata fileref="images/check.png" />
+ </imageobject>
+ </inlinemediaobject> This method implements the SQL/MM
+ specification: SQL-MM 3: 8.1.5, 9.5.6</para>
+ </refsection>
+
+ <refsection>
+ <title>Examples</title>
+
+ <programlisting>SELECT ST_AsText(ST_PointOnSurface('POINT(0 5)'::geometry));
+ st_astext
+------------
+ POINT(0 5)
+(1 row)
+
+SELECT ST_AsText(ST_PointOnSurface('LINESTRING(0 5, 0 10)'::geometry));
+ st_astext
+------------
+ POINT(0 5)
+(1 row)
+
+SELECT ST_AsText(ST_PointOnSurface('POLYGON((0 0, 0 5, 5 5, 5 0, 0 0))'::geometry));
+ st_astext
+----------------
+ POINT(2.5 2.5)
+(1 row)</programlisting>
+ </refsection>
+
+ <refsection>
+ <title>See Also</title>
+
+ <para><xref linkend="ST_Centroid" />, <xref linkend="ST_Point_Inside_Circle" /></para>
+ </refsection>
+ </refentry>
<refentry id="ST_Within">
<refnamediv>