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minor corrections

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git-svn-id: http://svn.osgeo.org/postgis/trunk@8176 b70326c6-7e19-0410-871a-916f4a2858ee
This commit is contained in:
Regina Obe 2011-11-18 13:24:40 +00:00
parent 63d0e6f221
commit 6a224caf22
1 changed files with 10 additions and 7 deletions
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17
doc/reference_raster.xml
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@ -3592,7 +3592,7 @@ WHERE rid = 2;
<para>Algorithm options are: 'NearestNeighbor', 'Bilinear', 'Cubic', 'CubicSpline', and 'Lanczos'. Refer to: <ulink url="http://www.gdal.org/gdalwarp.html">GDAL Warp resampling methods</ulink> for more details. NearestNeighbor is the fastest but worst interpoloation.
The <varname>scalex</varname>, <varname>scaley</varname> define the desired new ratio between geometry units and pixel units.</para>
<note><para>Note: This is different from <xref linkend="RT_ST_SetScale" /> in that ST_Rescale changes the underlying pixels of the raster using existing scale
and rescales it to the new input scales. <xref linkend="RT_ST_SetScale" />, on the otherhand, changes the metadata of the raster to correct a misSpecified scaling.</para></note>
and rescales it to the new input scales. <xref linkend="RT_ST_SetScale" />, on the other hand, changes the metadata of the raster to correct an originally mis-specified scaling.</para></note>
<para>Availability: 2.0.0 Requires GDAL 1.6.1+</para>
</refsection>
@ -6079,7 +6079,9 @@ SELECT ST_MapAlgebraFct(m1.rast, 1, m1.rast,3 ,
<para>(one raster version) Return a raster which values
are the result of a PLPGSQL user function involving a
neighborhood of values from the input raster band.</para>
neighborhood of values from the input raster band. The user function takes the neighborhood of pixel values
as an array of numbers, returns one number per neighborhood,
replaces existing pixel values of a neighborhood with that number. </para>
<variablelist>
<varlistentry>
@ -6104,7 +6106,8 @@ SELECT ST_MapAlgebraFct(m1.rast, 1, m1.rast,3 ,
</varlistentry>
<varlistentry>
<term>userfunction</term>
<listitem><para>PLPGSQL user function to apply to neighborhod pixels.</para></listitem>
<listitem><para>PLPGSQL/psql user function to apply to neighborhood pixels. The first element is a 2-dimensional
array of numbers representing the rectangular pixel neighborhood</para></listitem>
</varlistentry>
<varlistentry>
<term>args</term>
@ -6127,14 +6130,14 @@ CREATE OR REPLACE FUNCTION rast_avg(matrix float[][], nodatamode text, variadic
RETURNS float AS
$$
DECLARE
_matrix float[][];
_matrix float[][];
x1 integer;
x2 integer;
y1 integer;
y2 integer;
sum float;
BEGIN
_matrix := matrix;
_matrix := matrix;
sum := 0;
FOR x in array_lower(matrix, 1)..array_upper(matrix, 1) LOOP
FOR y in array_lower(matrix, 2)..array_upper(matrix, 2) LOOP
@ -6151,9 +6154,9 @@ CREATE OR REPLACE FUNCTION rast_avg(matrix float[][], nodatamode text, variadic
RETURN (sum*1.0/(array_upper(matrix,1)*array_upper(matrix,2) ))::integer ;
END;
$$
LANGUAGE 'plpgsql' IMMUTABLE COST 1000;
LANGUAGE 'plpgsql' IMMUTABLE COST 1000;
-- now we apply to our rescaled katrina averaging pixels within 2 pixels of each other --
-- now we apply to our raster averaging pixels within 2 pixels of each other in x and y direction --
SELECT ST_MapAlgebraFctNgb(rast, 1, '8BUI', 2, 2, 'rast_avg(float[][], text, text[])'::regprocedure, 'NULL', NULL) As neared
FROM katrinas_rescaled
limit 1;