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Postgres FD Implementation
Commit d28cd227 authored by Tom Lane's avatar Tom Lane
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Improve description of geometric operators.

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doc/src/sgml/func.sgml
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$Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.141 2003/02/19 03:12:22 momjian Exp $ $Header: /cvsroot/pgsql/doc/src/sgml/func.sgml,v 1.142 2003/03/03 03:31:23 tgl Exp $
PostgreSQL documentation PostgreSQL documentation
--> -->
...@@ -5436,11 +5436,26 @@ SELECT TIMESTAMP 'now'; ...@@ -5436,11 +5436,26 @@ SELECT TIMESTAMP 'now';
<entry>Number of points in path or polygon</entry> <entry>Number of points in path or polygon</entry>
<entry><literal># '((1,0),(0,1),(-1,0))'</literal></entry> <entry><literal># '((1,0),(0,1),(-1,0))'</literal></entry>
</row> </row>
<row>
<entry> @-@ </entry>
<entry>Length or circumference</entry>
<entry><literal>@-@ path '((0,0),(1,0))'</literal></entry>
</row>
<row>
<entry> @@ </entry>
<entry>Center of</entry>
<entry><literal>@@ circle '((0,0),10)'</literal></entry>
</row>
<row> <row>
<entry> ## </entry> <entry> ## </entry>
<entry>Point of closest proximity</entry> <entry>Point of closest proximity</entry>
<entry><literal>point '(0,0)' ## lseg '((2,0),(0,2))'</literal></entry> <entry><literal>point '(0,0)' ## lseg '((2,0),(0,2))'</literal></entry>
</row> </row>
<row>
<entry> &lt;-&gt; </entry>
<entry>Distance between</entry>
<entry><literal>circle '((0,0),1)' &lt;-&gt; circle '((5,0),1)'</literal></entry>
</row>
<row> <row>
<entry> &amp;&amp; </entry> <entry> &amp;&amp; </entry>
<entry>Overlaps?</entry> <entry>Overlaps?</entry>
...@@ -5448,82 +5463,82 @@ SELECT TIMESTAMP 'now'; ...@@ -5448,82 +5463,82 @@ SELECT TIMESTAMP 'now';
</row> </row>
<row> <row>
<entry> &amp;&lt; </entry> <entry> &amp;&lt; </entry>
<entry>Overlaps to left?</entry> <entry>Overlaps or is left of?</entry>
<entry><literal>box '((0,0),(1,1))' &amp;&lt; box '((0,0),(2,2))'</literal></entry> <entry><literal>box '((0,0),(1,1))' &amp;&lt; box '((0,0),(2,2))'</literal></entry>
</row> </row>
<row> <row>
<entry> &amp;&gt; </entry> <entry> &amp;&gt; </entry>
<entry>Overlaps to right?</entry> <entry>Overlaps or is right of?</entry>
<entry><literal>box '((0,0),(3,3))' &amp;&gt; box '((0,0),(2,2))'</literal></entry> <entry><literal>box '((0,0),(3,3))' &amp;&gt; box '((0,0),(2,2))'</literal></entry>
</row> </row>
<row>
<entry> &lt;-&gt; </entry>
<entry>Distance between</entry>
<entry><literal>circle '((0,0),1)' &lt;-&gt; circle '((5,0),1)'</literal></entry>
</row>
<row> <row>
<entry> &lt;&lt; </entry> <entry> &lt;&lt; </entry>
<entry>Left of?</entry> <entry>Left of?</entry>
<entry><literal>circle '((0,0),1)' &lt;&lt; circle '((5,0),1)'</literal></entry> <entry><literal>circle '((0,0),1)' &lt;&lt; circle '((5,0),1)'</literal></entry>
</row> </row>
<row>
<entry> &lt;^ </entry>
<entry>Is below?</entry>
<entry><literal>circle '((0,0),1)' &lt;^ circle '((0,5),1)'</literal></entry>
</row>
<row> <row>
<entry> &gt;&gt; </entry> <entry> &gt;&gt; </entry>
<entry>Is right of?</entry> <entry>Right of?</entry>
<entry><literal>circle '((5,0),1)' &gt;&gt; circle '((0,0),1)'</literal></entry> <entry><literal>circle '((5,0),1)' &gt;&gt; circle '((0,0),1)'</literal></entry>
</row> </row>
<row>
<entry> &lt;^ </entry>
<entry>Below?</entry>
<entry><literal>circle '((0,0),1)' &lt;^ circle '((0,5),1)'</literal></entry>
</row>
<row> <row>
<entry> &gt;^ </entry> <entry> &gt;^ </entry>
<entry>Is above?</entry> <entry>Above?</entry>
<entry><literal>circle '((0,5),1)' >^ circle '((0,0),1)'</literal></entry> <entry><literal>circle '((0,5),1)' >^ circle '((0,0),1)'</literal></entry>
</row> </row>
<row> <row>
<entry> ?# </entry> <entry> ?# </entry>
<entry>Intersects or overlaps</entry> <entry>Intersect?</entry>
<entry><literal>lseg '((-1,0),(1,0))' ?# box '((-2,-2),(2,2))'</literal></entry> <entry><literal>lseg '((-1,0),(1,0))' ?# box '((-2,-2),(2,2))'</literal></entry>
</row> </row>
<row> <row>
<entry> ?- </entry> <entry> ?- </entry>
<entry>Is horizontal?</entry> <entry>Horizontal?</entry>
<entry><literal>point '(1,0)' ?- point '(0,0)'</literal></entry> <entry><literal>?- lseg '((-1,0),(1,0))'</literal></entry>
</row> </row>
<row> <row>
<entry> ?-| </entry> <entry> ?- </entry>
<entry>Is perpendicular?</entry> <entry>Horizontally aligned?</entry>
<entry><literal>lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))'</literal></entry> <entry><literal>point '(1,0)' ?- point '(0,0)'</literal></entry>
</row> </row>
<row> <row>
<entry> @-@ </entry> <entry> ?| </entry>
<entry>Length or circumference</entry> <entry>Vertical?</entry>
<entry><literal>@-@ path '((0,0),(1,0))'</literal></entry> <entry><literal>?| lseg '((-1,0),(1,0))'</literal></entry>
</row> </row>
<row> <row>
<entry> ?| </entry> <entry> ?| </entry>
<entry>Is vertical?</entry> <entry>Vertically aligned?</entry>
<entry><literal>point '(0,1)' ?| point '(0,0)'</literal></entry> <entry><literal>point '(0,1)' ?| point '(0,0)'</literal></entry>
</row> </row>
<row>
<entry> ?-| </entry>
<entry>Perpendicular?</entry>
<entry><literal>lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))'</literal></entry>
</row>
<row> <row>
<entry> ?|| </entry> <entry> ?|| </entry>
<entry>Is parallel?</entry> <entry>Parallel?</entry>
<entry><literal>lseg '((-1,0),(1,0))' ?|| lseg '((-1,2),(1,2))'</literal></entry> <entry><literal>lseg '((-1,0),(1,0))' ?|| lseg '((-1,2),(1,2))'</literal></entry>
</row> </row>
<row> <row>
<entry> @ </entry> <entry> ~ </entry>
<entry>Contained or on</entry> <entry>Contains?</entry>
<entry><literal>point '(1,1)' @ circle '((0,0),2)'</literal></entry> <entry><literal>circle '((0,0),2)' ~ point '(1,1)'</literal></entry>
</row> </row>
<row> <row>
<entry> @@ </entry> <entry> @ </entry>
<entry>Center of</entry> <entry>Contained in or on?</entry>
<entry><literal>@@ circle '((0,0),10)'</literal></entry> <entry><literal>point '(1,1)' @ circle '((0,0),2)'</literal></entry>
</row> </row>
<row> <row>
<entry> ~= </entry> <entry> ~= </entry>
<entry>Same as</entry> <entry>Same as?</entry>
<entry><literal>polygon '((0,0),(1,1))' ~= polygon '((1,1),(0,0))'</literal></entry> <entry><literal>polygon '((0,0),(1,1))' ~= polygon '((1,1),(0,0))'</literal></entry>
</row> </row>
</tbody> </tbody>
......
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