From d28cd2273b81c17ce3ddcc09d90353daa229a2a7 Mon Sep 17 00:00:00 2001 From: Tom Lane <tgl@sss.pgh.pa.us> Date: Mon, 3 Mar 2003 03:31:23 +0000 Subject: [PATCH] Improve description of geometric operators. --- doc/src/sgml/func.sgml | 81 +++++++++++++++++++++++++----------------- 1 file 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 --> @@ -5436,11 +5436,26 @@ SELECT TIMESTAMP 'now'; <entry>Number of points in path or polygon</entry> <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> <-> </entry> + <entry>Distance between</entry> + <entry><literal>circle '((0,0),1)' <-> circle '((5,0),1)'</literal></entry> + </row> <row> <entry> && </entry> <entry>Overlaps?</entry> @@ -5448,82 +5463,82 @@ SELECT TIMESTAMP 'now'; </row> <row> <entry> &< </entry> - <entry>Overlaps to left?</entry> + <entry>Overlaps or is left of?</entry> <entry><literal>box '((0,0),(1,1))' &< box '((0,0),(2,2))'</literal></entry> </row> <row> <entry> &> </entry> - <entry>Overlaps to right?</entry> + <entry>Overlaps or is right of?</entry> <entry><literal>box '((0,0),(3,3))' &> box '((0,0),(2,2))'</literal></entry> </row> - <row> - <entry> <-> </entry> - <entry>Distance between</entry> - <entry><literal>circle '((0,0),1)' <-> circle '((5,0),1)'</literal></entry> - </row> <row> <entry> << </entry> <entry>Left of?</entry> <entry><literal>circle '((0,0),1)' << circle '((5,0),1)'</literal></entry> </row> - <row> - <entry> <^ </entry> - <entry>Is below?</entry> - <entry><literal>circle '((0,0),1)' <^ circle '((0,5),1)'</literal></entry> - </row> <row> <entry> >> </entry> - <entry>Is right of?</entry> + <entry>Right of?</entry> <entry><literal>circle '((5,0),1)' >> circle '((0,0),1)'</literal></entry> </row> + <row> + <entry> <^ </entry> + <entry>Below?</entry> + <entry><literal>circle '((0,0),1)' <^ circle '((0,5),1)'</literal></entry> + </row> <row> <entry> >^ </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> -- GitLab