[postgis-devel] Re: [postgis-users] bounding box incorrect on circularstring

[Mark Leslie]

Mark Cave-Ayland wrote:
> Ken Southerland wrote:
>> I am using Postgres 8.2.4 on Windows and am having an issue with the
>> Circular Strings in the Postgis extension.
>>
>> Why is the bounding box of circularstrings incorrectly calculated. 
>> Here I have a circular string that represents a nearly closed circle...
>>
>> db=# SELECT astext( geom ) FROM geom_table WHERE id = 0;
>>
>> ---------------------------------------
>>  CIRCULARSTRING(220268.439465645 150415.359530563,220227.333322076
>> 150505.561285
>> 879,220227.353105332 150406.434743975)
>>
>>
>> ... but it's extent is a rectangle that only covers the two endpoints
>> and ignores the middle point and the arc segments in-between...
>>
>> db=# SELECT astext( extent( geom ) ) FROM geom_table WHERE id = 0;
>>
>> ---------------------------------------------------------------
>>  POLYGON((220227.34375 150406.421875,220227.34375
>> 150415.375,220268.453125 15041
>> 5.375,220268.453125 150406.421875,220227.34375 150406.421875))
>>
>> ... is this a known issue that is being addressed?
>>
>> Ken
>
> Hi Ken,
>
> Which PostGIS version are you using? Any chance you could file this on
> the PostGIS bugtracker?
>
>
> Many thanks,
>
> Mark.
>
I've created an issue for this
<http://code.google.com/p/postgis/issues/detail?id=58>, and have a
working patch for the 1.3 branch.  Unfortunately, I'm getting regression
failures in regress_ogc_prep (both before and after the patch) that are
preventing me from committing.  The errors I'm getting are...

  ERROR:  function st_intersects(unknown, text, integer) does not exist
  ERROR:  function st_intersects(geometry, geometry, integer) does not exist
  ERROR:  function st_intersects(unknown, unknown, integer) does not exist

... for various combinations of geometry, unknown and text.  Are these a
result of our ongoing prepared geometry API indecision and consequently
ignorable?

-- 
Mark Leslie
Geospatial Software Architect
LISAsoft

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