[postgis-tickets] [PostGIS] #3723: st_geohash not correct for some multipoint

[PostGIS]

#3723: st_geohash not correct for some multipoint
----------------------+---------------------------
  Reporter:  hzhang   |      Owner:  pramsey
      Type:  defect   |     Status:  new
  Priority:  high     |  Milestone:  PostGIS 2.3.3
 Component:  postgis  |    Version:  2.2.x
Resolution:           |   Keywords:  st_geohash
----------------------+---------------------------

Comment (by hzhang):

 another example:

 for LINESTRING (1 1, 40 40)

 {{{
 bbox of that linestring is:
 select ST_extent('LINESTRING (1 1, 40 40)');
    st_extent
 ----------------
  BOX(1 1,40 40)
 (1 row)

 and bbox for geohash 's' is:
 select ST_Box2dFromGeoHash('s');
  st_box2dfromgeohash
 ---------------------
  BOX(0 0,45 45)
 (1 row)


 it clearly shows that linestring is within that 's' bbox, but the
 st_geohash function doesn't return s:

 SELECT ST_GeoHash(ST_GeographyFromText('LINESTRING (1 1, 40 40)'))
 geohash;
  geohash
 ---------

 (1 row)

 or:

 postgres=# select ST_Within(a , b) from ( select ST_extent('LINESTRING (1
 1, 40 40)') as a, ST_Box2dFromGeoHash('s') as b) as foo;
  st_within
 -----------
  t
 (1 row)



 }}}

--
Ticket URL: <https://trac.osgeo.org/postgis/ticket/3723#comment:1>
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