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moved over &&, &<, and = from reference.xml to reference_new.xml in the documentation

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git-svn-id: http://svn.osgeo.org/postgis/trunk@3548 b70326c6-7e19-0410-871a-916f4a2858ee
This commit is contained in:
Kevin Neufeld 2009-01-21 23:26:29 +00:00
parent 4a4c305bfa
commit b680649934
2 changed files with 216 additions and 35 deletions
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31
doc/reference.xml
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@ -158,27 +158,6 @@
<title>Operators</title>
<variablelist>
<varlistentry>
<term>A = B</term>
<listitem>
<para>The "=" operator returns true if A's bounding box
is the same as B's bounding box.</para>
<note><para>This is cause for a lot of confusion. When you compare geometryA = geometryB it will return
true even when the geometries are clearly different if their bounding boxes are the same. To check for
true equality use <xref linkend="ST_OrderingEquals"/> or <xref linkend="ST_Equals"/></para></note>
</listitem>
</varlistentry>
<varlistentry>
<term>A &amp;&lt; B</term>
<listitem>
<para>The "&amp;&lt;" operator returns true if A's bounding box
overlaps or is to the left of B's bounding box.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>A &amp;&gt; B</term>
@ -269,16 +248,6 @@
contains B's bounding box.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>A &amp;&amp; B</term>
<listitem>
<para>The "&amp;&amp;" operator is the "overlaps" operator. If A's
bounding box overlaps B's bounding box the operator returns
true.</para>
</listitem>
</varlistentry>
</variablelist>
</sect2>
</sect1>

218
doc/reference_new.xml
View file

@ -7639,9 +7639,221 @@ F000000000000000000000000000000000000000000000000');
</sect1>
<sect1>
<title>Operators</title>
<para></para>
</sect1>
<title>Operators</title>
<refentry id="ST_Geometry_Overlaps">
<refnamediv>
<refname>&amp;&amp;</refname>
<refpurpose>Returns <varname>TRUE</varname> if A overlaps B.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<!-- TODO: Ideally, it would be nice if this coule be reordered to
"boolean (geometry A && geometry B)" instead of
"boolean &&( geometry A, geometry B)" -->
<funcdef>boolean <function>&amp;&amp;</function></funcdef>
<paramdef>
<type>geometry </type>
<parameter>A</parameter>
</paramdef>
<paramdef>
<type>geometry </type>
<parameter>B</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsection>
<title>Description</title>
<para>The <varname>&amp;&amp;</varname> operator returns <varname>TRUE</varname> if the bounding box of geometry A overlaps the bounding box of geometry B.</para>
<note><para>This function call will automatically include a bounding box
comparison that will make use of any indexes that are available on the
geometries.</para></note>
</refsection>
<refsection>
<title>Examples</title>
<programlisting>SELECT tbl1.column1, tbl2.column1, tbl1.column2 &amp;&amp; tbl2.column2 AS overlaps
FROM ( VALUES
(1, 'LINESTRING(0 0, 3 3)'::geometry),
(2, 'LINESTRING(0 1, 0 5)'::geometry)) AS tbl1,
( VALUES
(3, 'LINESTRING(1 2, 4 6)'::geometry)) AS tbl2;
column1 | column1 | overlaps
---------+---------+----------
1 | 3 | t
2 | 3 | f
(2 rows)</programlisting>
</refsection>
<refsection>
<title>See Also</title>
<para><xref linkend="ST_Geometry_Overleft" /></para>
</refsection>
</refentry>
<refentry id="ST_Geometry_Overleft">
<refnamediv>
<refname>&amp;&lt;</refname>
<refpurpose>Returns <varname>TRUE</varname> if A overlaps or is to the left of B.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<!-- TODO: Ideally, it would be nice if this coule be reordered to
"boolean (geometry A &< geometry B)" instead of
"boolean &&( geometry A, geometry B)" -->
<funcdef>boolean <function>&amp;&lt;</function></funcdef>
<paramdef>
<type>geometry </type>
<parameter>A</parameter>
</paramdef>
<paramdef>
<type>geometry </type>
<parameter>B</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsection>
<title>Description</title>
<para>The <varname>&amp;&lt;</varname> operator returns <varname>TRUE</varname> if the bounding box of geometry A
overlaps or is to the left of the bounding box of geometry B.</para>
</refsection>
<refsection>
<title>Examples</title>
<programlisting>SELECT tbl1.column1, tbl2.column1, tbl1.column2 &amp;&lt; tbl2.column2 AS overlaps
FROM
( VALUES
(1, 'LINESTRING(1 2, 4 6)'::geometry)) AS tbl1,
( VALUES
(2, 'LINESTRING(0 0, 3 3)'::geometry),
(3, 'LINESTRING(0 1, 0 5)'::geometry),
(4, 'LINESTRING(6 0, 6 1)'::geometry)) AS tbl2;
column1 | column1 | overlaps
---------+---------+----------
1 | 2 | f &lt;---- FIXME: this looks like a bug.
1 | 3 | f
1 | 4 | t
(3 rows)</programlisting>
</refsection>
<refsection>
<title>See Also</title>
<para><xref linkend="ST_Geometry_Overlaps" /></para>
</refsection>
</refentry>
<refentry id="ST_Geometry_EQ">
<refnamediv>
<refname>&#61;</refname>
<refpurpose>Returns <varname>TRUE</varname> if A is the same as B.</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcprototype>
<!-- TODO: Ideally, it would be nice if this coule be reordered to
"boolean (geometry A = geometry B)" instead of
"boolean =( geometry A, geometry B)" -->
<funcdef>boolean <function>&#61;</function></funcdef>
<paramdef>
<type>geometry </type>
<parameter>A</parameter>
</paramdef>
<paramdef>
<type>geometry </type>
<parameter>B</parameter>
</paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsection>
<title>Description</title>
<para>The <varname>&#61;</varname> operator returns <varname>TRUE</varname> if the bounding box of geometry A
is the same as the bounding box of geometry B. PostgreSQL uses the =, &lt;, and &gt; operators defined for geometries to
perform internal orderings and comparison of geometries (ie. in a GROUP BY or ORDER BY clause).</para>
<note>
<para>This is cause for a lot of confusion. When you compare geometryA =
geometryB it will return true even when the geometries are clearly
different IF their bounding boxes are the same. To check for true
equality use <xref linkend="ST_OrderingEquals" /> or <xref
linkend="ST_Equals" /></para>
</note>
</refsection>
<refsection>
<title>Examples</title>
<programlisting>SELECT 'LINESTRING(0 0, 0 1, 1 0)'::geometry = 'LINESTRING(1 1, 0 0)'::geometry;
?column?
----------
t
(1 row)
SELECT ST_AsText(column1)
FROM ( VALUES
('LINESTRING(0 0, 1 1)'::geometry),
('LINESTRING(1 1, 0 0)'::geometry)) AS foo;
st_astext
---------------------
LINESTRING(0 0,1 1)
LINESTRING(1 1,0 0)
(2 rows)
-- Note: the GROUP BY uses the "=" to compare for geometry equivalency.
SELECT ST_AsText(column1)
FROM ( VALUES
('LINESTRING(0 0, 1 1)'::geometry),
('LINESTRING(1 1, 0 0)'::geometry)) AS foo
GROUP BY column1;
st_astext
---------------------
LINESTRING(0 0,1 1)
(1 row)</programlisting>
</refsection>
<refsection>
<title>See Also</title>
<para><xref linkend="ST_Equals" />, <xref linkend="ST_OrderingEquals" />
<!--, <xref linkend="ST_Geometry_LT" />, <xref linkend="ST_Geometry_GT" /> --></para>
</refsection>
</refentry>
</sect1>
<sect1 id="Spatial_Relationships_Measurements">