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authorTom Lane <tgl@sss.pgh.pa.us>2003-03-03 03:31:23 +0000
committerTom Lane <tgl@sss.pgh.pa.us>2003-03-03 03:31:23 +0000
commitd28cd2273b81c17ce3ddcc09d90353daa229a2a7 (patch)
tree2eee70ac7fe300eed517ee91848f37a8b8023cd6
parentb9ddb63307209f70b86b5eb5427bd4b374b2559f (diff)
downloadpostgresql-d28cd2273b81c17ce3ddcc09d90353daa229a2a7.tar.gz
postgresql-d28cd2273b81c17ce3ddcc09d90353daa229a2a7.zip
Improve description of geometric operators.
-rw-r--r--doc/src/sgml/func.sgml81
1 files changed, 48 insertions, 33 deletions
diff --git a/doc/src/sgml/func.sgml b/doc/src/sgml/func.sgml
index b81dc923871..524542d1df2 100644
--- a/doc/src/sgml/func.sgml
+++ b/doc/src/sgml/func.sgml
@@ -1,5 +1,5 @@
<!--
-$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
-->
@@ -5437,93 +5437,108 @@ SELECT TIMESTAMP 'now';
<entry><literal># '((1,0),(0,1),(-1,0))'</literal></entry>
</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>
<entry> ## </entry>
<entry>Point of closest proximity</entry>
<entry><literal>point '(0,0)' ## lseg '((2,0),(0,2))'</literal></entry>
</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>
<entry> &amp;&amp; </entry>
<entry>Overlaps?</entry>
<entry><literal>box '((0,0),(1,1))' &amp;&amp; box '((0,0),(2,2))'</literal></entry>
</row>
<row>
<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>
</row>
<row>
<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>
</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>
<entry> &lt;&lt; </entry>
<entry>Left of?</entry>
<entry><literal>circle '((0,0),1)' &lt;&lt; circle '((5,0),1)'</literal></entry>
</row>
<row>
- <entry> &lt;^ </entry>
- <entry>Is below?</entry>
- <entry><literal>circle '((0,0),1)' &lt;^ circle '((0,5),1)'</literal></entry>
- </row>
- <row>
<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>
</row>
<row>
+ <entry> &lt;^ </entry>
+ <entry>Below?</entry>
+ <entry><literal>circle '((0,0),1)' &lt;^ circle '((0,5),1)'</literal></entry>
+ </row>
+ <row>
<entry> &gt;^ </entry>
- <entry>Is above?</entry>
+ <entry>Above?</entry>
<entry><literal>circle '((0,5),1)' >^ circle '((0,0),1)'</literal></entry>
</row>
<row>
<entry> ?# </entry>
- <entry>Intersects or overlaps</entry>
+ <entry>Intersect?</entry>
<entry><literal>lseg '((-1,0),(1,0))' ?# box '((-2,-2),(2,2))'</literal></entry>
</row>
<row>
<entry> ?- </entry>
- <entry>Is horizontal?</entry>
- <entry><literal>point '(1,0)' ?- point '(0,0)'</literal></entry>
+ <entry>Horizontal?</entry>
+ <entry><literal>?- lseg '((-1,0),(1,0))'</literal></entry>
</row>
<row>
- <entry> ?-| </entry>
- <entry>Is perpendicular?</entry>
- <entry><literal>lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))'</literal></entry>
+ <entry> ?- </entry>
+ <entry>Horizontally aligned?</entry>
+ <entry><literal>point '(1,0)' ?- point '(0,0)'</literal></entry>
</row>
<row>
- <entry> @-@ </entry>
- <entry>Length or circumference</entry>
- <entry><literal>@-@ path '((0,0),(1,0))'</literal></entry>
+ <entry> ?| </entry>
+ <entry>Vertical?</entry>
+ <entry><literal>?| lseg '((-1,0),(1,0))'</literal></entry>
</row>
<row>
<entry> ?| </entry>
- <entry>Is vertical?</entry>
+ <entry>Vertically aligned?</entry>
<entry><literal>point '(0,1)' ?| point '(0,0)'</literal></entry>
</row>
<row>
+ <entry> ?-| </entry>
+ <entry>Perpendicular?</entry>
+ <entry><literal>lseg '((0,0),(0,1))' ?-| lseg '((0,0),(1,0))'</literal></entry>
+ </row>
+ <row>
<entry> ?|| </entry>
- <entry>Is parallel?</entry>
+ <entry>Parallel?</entry>
<entry><literal>lseg '((-1,0),(1,0))' ?|| lseg '((-1,2),(1,2))'</literal></entry>
</row>
<row>
- <entry> @ </entry>
- <entry>Contained or on</entry>
- <entry><literal>point '(1,1)' @ circle '((0,0),2)'</literal></entry>
+ <entry> ~ </entry>
+ <entry>Contains?</entry>
+ <entry><literal>circle '((0,0),2)' ~ point '(1,1)'</literal></entry>
</row>
<row>
- <entry> @@ </entry>
- <entry>Center of</entry>
- <entry><literal>@@ circle '((0,0),10)'</literal></entry>
+ <entry> @ </entry>
+ <entry>Contained in or on?</entry>
+ <entry><literal>point '(1,1)' @ circle '((0,0),2)'</literal></entry>
</row>
<row>
<entry> ~= </entry>
- <entry>Same as</entry>
+ <entry>Same as?</entry>
<entry><literal>polygon '((0,0),(1,1))' ~= polygon '((1,1),(0,0))'</literal></entry>
</row>
</tbody>