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example how to use variadic version of ST_Reclass raster function, finish off reclassarg type description, add summarystats type
git-svn-id: http://svn.osgeo.org/postgis/trunk@7310 b70326c6-7e19-0410-871a-916f4a2858ee
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Regina Obe
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@ -344,23 +344,72 @@ VALUES (1,
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</varlistentry>
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<varlistentry>
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<term><parameter>reclassexpr </parameter><type>text</type></term>
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<listitem><para>Mathemetical expression defining how to map band to new band.</para></listitem>
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<listitem><para>range expression consisting of - (define range) and : to define mapping that defines how to map old band values to new band values. ( means >, ) means less than, ] < or equal, [ means > or equal</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>pixeltype </parameter><type>text</type></term>
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<listitem><para>One of defined pixel types as described in <xref linkend="RT_ST_BandPixelType" /></para></listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>nodataval </parameter><type>double precision</type></term>
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<listitem><para>Value to treat as no data. For image outputs that support transparency, these will be blank.</para></listitem>
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</varlistentry>
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</variablelist>
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</refsection>
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<refsection>
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<title>Example: Reclassify band 2 as an 8BUI where 255 is nodata value</title>
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<programlisting>SELECT ROW(2, '0-100:1-10, 101-500:11-150,501 - 10000: 151-254', '8BUI', 255)::reclassarg;</programlisting>
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</refsection>
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<refsection>
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<title>Example: Reclassify band 1 as an 1BB and no nodata value defined</title>
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<programlisting>SELECT ROW(2, '0-100]:0, (100-255:1', '1BB', NULL)::reclassarg;</programlisting>
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</refsection>
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<refsection>
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<title>See Also</title>
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<para><xref linkend="RT_ST_Reclass" /></para>
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</refsection>
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</refentry>
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<refentry id="summarystats">
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<refnamediv>
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<refname>summarystats</refname>
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<refpurpose>A composite type used as output the ST_SummaryStats function.</refpurpose>
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</refnamediv>
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<refsection>
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<title>Description</title>
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<para>A composite type used as output the ST_SummaryStats function. Note that depending on <varname>exclude_nodata_value</varname> of function, may or may not contain nodata pixels.</para>
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<variablelist>
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<varlistentry>
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<term><parameter>count </parameter><type>bigint</type></term>
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<listitem><para>count of pixels in raster band. Depending on arguments may or many not include nodata pixel values.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>sum </parameter><type>double precision</type></term>
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<listitem><para>sum of all pixel values in band</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>mean </parameter><type>double precision</type></term>
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<listitem><para>Mean of pixel values</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>stddev </parameter><type>double precision</type></term>
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<listitem><para>Standard deviation of pixel values.</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>min </parameter><type>double precision</type></term>
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<listitem><para>Minimum pixel value</para></listitem>
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</varlistentry>
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<varlistentry>
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<term><parameter>max </parameter><type>double precision</type></term>
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<listitem><para>Maximum pixel value</para></listitem>
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</varlistentry>
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</variablelist>
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</refsection>
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<refsection>
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<title>See Also</title>
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<para><xref linkend="RT_ST_SummaryStats" /></para>
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</refsection>
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</refentry>
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</sect1>
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<sect1 id="Raster_Management_Functions">
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<title>Raster Management Functions</title>
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@ -3524,7 +3573,7 @@ FROM (SELECT band, ST_SummaryStats('o_4_boston','rast', band,true,0.25) As stats
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<refsection>
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<title>See Also</title>
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<para><xref linkend="RT_ST_Count" /></para>
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<para><xref linkend="RT_ST_Count" />, <para><xref linkend="summarystats" /></para></para>
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</refsection>
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</refentry>
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@ -4534,19 +4583,19 @@ POLYGON((3427928 5793243.85,3427928 5793243.8,3427928 5793243.75,3427927.85 5793
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</refsection>
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<refsection>
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<title>Examples</title>
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<title>Examples Basic</title>
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<para>Create a new raster from the original where band 2 is converted from 8BUI to 4BUI and all values from 251-255 are set to nodata value.</para>
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<programlisting>ALTER TABLE dummy_rast ADD COLUMN reclass_rast raster;
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UPDATE dummy_rast SET reclass_rast = ST_Reclass(rast,2,'0-87:1-10, 88-100:11-15, 101-254:0-0', '4BUI',0) WHERE rid = 2;
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SELECT i as row, j as col, ST_Value(rast,2,i,j) As origval,
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SELECT i as col, j as row, ST_Value(rast,2,i,j) As origval,
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ST_Value(reclass_rast, 2, i, j) As reclassval,
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ST_Value(reclass_rast, 2, i, j, false) As reclassval_include_nodata
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FROM dummy_rast CROSS JOIN generate_series(1, 3) AS i CROSS JOIN generate_series(1,3) AS j
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WHERE rid = 2;
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row | col | origval | reclassval | reclassval_include_nodata
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col | row | origval | reclassval | reclassval_include_nodata
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-----+-----+---------+------------+---------------------------
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1 | 1 | 78 | 9 | 9
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2 | 1 | 98 | 14 | 14
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@ -4559,10 +4608,41 @@ WHERE rid = 2;
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3 | 3 | 169 | | 0</programlisting>
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<!-- TODO: Add more examples using reclass arg -->
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</refsection>
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<refsection>
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<title>Example: Advanced using multiple reclassargs</title>
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<para>Create a new raster from the original where band 1,2,3 is converted to 1BB,4BUI, 4BUI respectively and reclassified.
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Note this uses the variadic <varname>reclassarg</varname> argument which can take as input an indefinite number of reclassargs (theoretically as many bands as you have) </para>
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<programlisting>UPDATE dummy_rast SET reclass_rast =
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ST_Reclass(rast,
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ROW(2,'0-87]:1-10, (87-100]:11-15, (101-254]:0-0', '4BUI',NULL)::reclassarg,
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ROW(1,'0-253]:1, 254:0', '1BB', NULL)::reclassarg,
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ROW(3,'0-70]:1, (70-86:2, [86-150):3, [150-255:4', '4BUI', NULL)::reclassarg
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) WHERE rid = 2;
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SELECT i as col, j as row,ST_Value(rast,1,i,j) As ov1, ST_Value(reclass_rast, 1, i, j) As rv1,
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ST_Value(rast,2,i,j) As ov2, ST_Value(reclass_rast, 2, i, j) As rv2,
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ST_Value(rast,3,i,j) As ov3, ST_Value(reclass_rast, 3, i, j) As rv3
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FROM dummy_rast CROSS JOIN generate_series(1, 3) AS i CROSS JOIN generate_series(1,3) AS j
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WHERE rid = 2;
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col | row | ov1 | rv1 | ov2 | rv2 | ov3 | rv3
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----+-----+-----+-----+-----+-----+-----+-----
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1 | 1 | 253 | 1 | 78 | 9 | 70 | 1
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2 | 1 | 254 | 0 | 98 | 14 | 86 | 3
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3 | 1 | 253 | 1 | 122 | 0 | 100 | 3
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1 | 2 | 253 | 1 | 96 | 14 | 80 | 2
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2 | 2 | 254 | 0 | 118 | 0 | 108 | 3
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3 | 2 | 254 | 0 | 180 | 0 | 162 | 4
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1 | 3 | 250 | 1 | 99 | 15 | 90 | 3
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2 | 3 | 254 | 0 | 112 | 0 | 108 | 3
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3 | 3 | 254 | 0 | 169 | 0 | 175 | 4</programlisting>
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</refsection>
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<refsection>
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<title>See Also</title>
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<para><xref linkend="RT_ST_BandPixelType" />, <xref linkend="reclassarg" /></para>
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<para><xref linkend="RT_ST_BandPixelType" />, <xref linkend="reclassarg" />, <para><xref linkend="RT_ST_Value" /></para></para>
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</refsection>
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</refentry>
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</sect1>
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