<refentry id="RT_ST_Value">
<refnamediv>
<refname>ST_Value</refname>
- <refpurpose>Returns the value of a given band in a given columnx, rowy pixel or at a particular geometric point. Band numbers start at 1 and assumed to be 1 if not specified.</refpurpose>
+ <refpurpose>Returns the value of a given band in a given columnx, rowy pixel or at a particular geometric point. Band numbers start at 1 and assumed to be 1 if not specified. If <varname>hasnodata</varname> is set to true, then only non <varname>nodata</varname> pixels are considered. If <varname>hasnodata</varname> is not passed in then reads it from metadata of raster.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcdef>double precision <function>ST_Value</function></funcdef>
<paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
<paramdef><type>geometry </type> <parameter>pt</parameter></paramdef>
+ </funcprototype>
+ <funcprototype>
+ <funcdef>double precision <function>ST_Value</function></funcdef>
+ <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+ <paramdef><type>geometry </type> <parameter>pt</parameter></paramdef>
+ <paramdef><type>boolean </type> <parameter>hasnodata</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>double precision <function>ST_Value</function></funcdef>
<paramdef><type>integer </type> <parameter>bandnum</parameter></paramdef>
<paramdef><type>geometry </type> <parameter>pt</parameter></paramdef>
</funcprototype>
+ <funcprototype>
+ <funcdef>double precision <function>ST_Value</function></funcdef>
+ <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>bandnum</parameter></paramdef>
+ <paramdef><type>geometry </type> <parameter>pt</parameter></paramdef>
+ <paramdef><type>boolean </type> <parameter>hasnodata</parameter></paramdef>
+ </funcprototype>
<funcprototype>
<funcdef>double precision <function>ST_Value</function></funcdef>
<paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
<paramdef><type>integer </type> <parameter>columnx</parameter></paramdef>
<paramdef><type>integer </type> <parameter>rowy</parameter></paramdef>
</funcprototype>
+ <funcprototype>
+ <funcdef>double precision <function>ST_Value</function></funcdef>
+ <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>columnx</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>rowy</parameter></paramdef>
+ <paramdef><type>boolean </type> <parameter>hasnodata</parameter></paramdef>
+ </funcprototype>
+ <funcprototype>
+ <funcdef>double precision <function>ST_Value</function></funcdef>
+ <paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>bandnum</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>columnx</parameter></paramdef>
+ <paramdef><type>integer </type> <parameter>rowy</parameter></paramdef>
+ </funcprototype>
<funcprototype>
<funcdef>double precision <function>ST_Value</function></funcdef>
<paramdef><type>raster </type> <parameter>rast</parameter></paramdef>
<paramdef><type>integer </type> <parameter>bandnum</parameter></paramdef>
<paramdef><type>integer </type> <parameter>columnx</parameter></paramdef>
<paramdef><type>integer </type> <parameter>rowy</parameter></paramdef>
+ <paramdef><type>boolean </type> <parameter>hasnodata</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsection>
<title>Description</title>
- <para>Returns the value of a given band in a given columnx, rowy pixel or at a given geometry point. Band numbers start at 1 and band is assumed to be 1 if not specified.</para>
+ <para>Returns the value of a given band in a given columnx, rowy pixel or at a given geometry point. Band numbers start at 1 and band is assumed to be 1 if not specified.
+ If <varname>hasnodata</varname> is set to true, then only non <varname>nodata</varname> pixels are considered. If <varname>hasnodata</varname> is set to false, then all pixels are considered.</para>
-
+ <para>Changed: 2.0.0 hasnodata optional argument was added.</para>
</refsection>
<refsection>
, <xref linkend="RT_ST_ScaleY" />, <xref linkend="RT_ST_UpperLeftX" />,
<xref linkend="RT_ST_UpperLeftY" />, <xref linkend="RT_ST_SRID" />, <xref linkend="ST_AsText" />,
, <xref linkend="ST_Point" />, <xref linkend="ST_MakeEnvelope" />,
- <xref linkend="ST_Intersects" /></para>
+ <xref linkend="ST_Intersects" />, <xref linkend="ST_Intersection" /></para>
</refsection>
</refentry>