mirror of
https://git.osgeo.org/gitea/postgis/postgis
synced 2024-10-24 09:02:37 +00:00
fix some typos, revise example demonstrating difference between intersection and union. include pictures.
git-svn-id: http://svn.osgeo.org/postgis/trunk@8122 b70326c6-7e19-0410-871a-916f4a2858ee
This commit is contained in:
parent
9cf7857f1d
commit
d10943d4f5
BIN
doc/html/images/st_mapalgebraexpr2_01.png
Normal file
BIN
doc/html/images/st_mapalgebraexpr2_01.png
Normal file
Binary file not shown.
After Width: | Height: | Size: 802 B |
BIN
doc/html/images/st_mapalgebraexpr2_02.png
Normal file
BIN
doc/html/images/st_mapalgebraexpr2_02.png
Normal file
Binary file not shown.
After Width: | Height: | Size: 1.5 KiB |
|
@ -5284,7 +5284,7 @@ WHERE rid=167;
|
|||
<paramdef choice='opt'><type>text </type> <parameter>extenttype=INTERSECTION</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>text </type> <parameter>nodata1expr=NULL</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>text </type> <parameter>nodata2expr=NULL</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>dobule precision </type> <parameter>nodatanodataval=NULL</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>double precision </type> <parameter>nodatanodataval=NULL</parameter></paramdef>
|
||||
</funcprototype>
|
||||
|
||||
<funcprototype>
|
||||
|
@ -5298,7 +5298,7 @@ WHERE rid=167;
|
|||
<paramdef choice='opt'><type>text </type> <parameter>extenttype=INTERSECTION</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>text </type> <parameter>nodata1expr=NULL</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>text </type> <parameter>nodata2expr=NULL</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>dobule precision </type> <parameter>nodatanodataval=NULL</parameter></paramdef>
|
||||
<paramdef choice='opt'><type>double precision </type> <parameter>nodatanodataval=NULL</parameter></paramdef>
|
||||
</funcprototype>
|
||||
</funcsynopsis>
|
||||
</refsynopsisdiv>
|
||||
|
@ -5351,11 +5351,12 @@ WHERE rid=167;
|
|||
</refsection>
|
||||
|
||||
<refsection>
|
||||
<title>Example: 2 Band Intersection</title>
|
||||
<title>Example: 2 Band Intersection and Union</title>
|
||||
|
||||
<para>Create a new 1 band raster from our original that is a function of modulo 2 of the original raster band.</para>
|
||||
<programlisting>
|
||||
--Create a cool set of rasters --
|
||||
DROP TABLE IF EXISTS fun_shapes;
|
||||
CREATE TABLE fun_shapes(rid serial PRIMARY KEY, fun_name text, rast raster);
|
||||
|
||||
-- Insert some cool shapes around Boston in Massachusetts state plane meters --
|
||||
|
@ -5365,7 +5366,7 @@ VALUES ('ref', ST_AsRaster(ST_MakeEnvelope(235229, 899970, 237229, 901930,26986)
|
|||
INSERT INTO fun_shapes(fun_name,rast)
|
||||
WITH ref(rast) AS (SELECT rast FROM fun_shapes WHERE fun_name = 'ref' )
|
||||
SELECT 'area' AS fun_name, ST_AsRaster(ST_Buffer(ST_SetSRID(ST_Point(236229, 900930),26986), 1000),
|
||||
ref.rast,'8BUI', 118, 0) As rast
|
||||
ref.rast,'8BUI', 10, 0) As rast
|
||||
FROM ref
|
||||
UNION ALL
|
||||
SELECT 'rand bubbles',
|
||||
|
@ -5373,18 +5374,47 @@ SELECT 'rand bubbles',
|
|||
(SELECT ST_Collect(geom)
|
||||
FROM (SELECT ST_Buffer(ST_SetSRID(ST_Point(236229 + i*random()*100, 900930 + j*random()*100),26986), random()*20) As geom
|
||||
FROM generate_series(1,10) As i, generate_series(1,10) As j
|
||||
) As foo ), ref.rast,'8BUI', 100, 0)
|
||||
) As foo ), ref.rast,'8BUI', 200, 0)
|
||||
FROM ref;
|
||||
|
||||
--map them -
|
||||
SELECT st_mapalgebraexpr(
|
||||
area.rast, bub.rast, 'rast1', NULL, 'INTERSECTION')
|
||||
SELECT ST_MapAlgebraExpr(
|
||||
area.rast, bub.rast, 'rast2', '8BUI', 'INTERSECTION', 'rast2', 'rast1') As interrast,
|
||||
ST_MapAlgebraExpr(
|
||||
area.rast, bub.rast, 'rast2', '8BUI', 'UNION', 'rast2', 'rast1') As unionrast
|
||||
FROM
|
||||
(SELECT rast FROM fun_shapes WHERE
|
||||
fun_name = 'area') As area
|
||||
CROSS JOIN (SELECT rast FROM fun_shapes WHERE
|
||||
fun_name = 'rand bubbles') As bub;
|
||||
CROSS JOIN (SELECT rast
|
||||
FROM fun_shapes WHERE
|
||||
fun_name = 'rand bubbles') As bub
|
||||
</programlisting>
|
||||
<informaltable>
|
||||
<tgroup cols="2">
|
||||
<tbody>
|
||||
<row>
|
||||
<entry><informalfigure>
|
||||
<mediaobject>
|
||||
<imageobject>
|
||||
<imagedata fileref="images/st_mapalgebraexpr2_01.png" />
|
||||
</imageobject>
|
||||
<caption><para>mapalgebra intersection</para></caption>
|
||||
</mediaobject>
|
||||
</informalfigure>
|
||||
</entry>
|
||||
<entry><informalfigure>
|
||||
<mediaobject>
|
||||
<imageobject>
|
||||
<imagedata fileref="images/st_mapalgebraexpr2_02.png" />
|
||||
</imageobject>
|
||||
<caption><para>map algebra union</para></caption>
|
||||
</mediaobject>
|
||||
</informalfigure>
|
||||
</entry>
|
||||
</row>
|
||||
</tbody>
|
||||
</tgroup>
|
||||
</informaltable>
|
||||
</refsection>
|
||||
|
||||
<refsection>
|
||||
|
|
Loading…
Reference in a new issue