[postgis-users] st_dist, st_sphere, st_spheroid - overhead/efficiency question

[Paul Ramsey]

Are you referring to the first record? There is no ordering guarantee
in database tables. The first record in your file could be the
12,000th in the database. The coordinates of that south dakota record
do look to be in south dakota. Seems a good sign to me.

On Thu, Jul 9, 2009 at 11:20 AM, Bo Coughlin<bo at rekindl.com> wrote:
> right. but the location (in raw original) is:
> 1442 E FORT AVE  BALTIMORE MD 21230  39.269318 -76.594162
> where it is now:
> 308th Aveu  Gettysburg, SD 57442POINT(-100.000971435723 45.0003533555503)
>
> that's a bad thing...
>
>
> On Thu, Jul 9, 2009 at 2:06 PM, Paul Ramsey <pramsey at cleverelephant.ca>
> wrote:
>>
>> The coordinates you pasted in are valid points in the continental USA...
>>
>> select st_srid(the_geom), st_astext(the_geom) from market_locations limit
>> 1;
>> 4326    POINT(-77.1042756692815 38.995397678429)
>>
>> select st_srid(the_geom), st_astext(the_geom) from customer_locations
>> limit 1;
>> 4326    POINT(-100.000971435723 45.0003533555503)
>>
>> P
>>
>> On Thu, Jul 9, 2009 at 10:46 AM, Bo Coughlin<bo at rekindl.com> wrote:
>> > Hmmm....I just looked again at the points - they no longer match the
>> > original lat/lon coordinates, could I have somehow altered these via
>> > reprojecting them?
>> > Bo Coughlin
>> > bo at rekindl.com
>> > 704.414.0805
>> >
>> >
>> > On Thu, Jul 9, 2009 at 1:38 PM, Bo Coughlin <bo at rekindl.com> wrote:
>> >>
>> >> Tried - got nothing returned...little scary. - bo
>> >>
>> >> Bo Coughlin
>> >> bo at rekindl.com
>> >> 704.414.0805
>> >>
>> >>
>> >> On Thu, Jul 9, 2009 at 1:16 PM, Paul Ramsey <pramsey at cleverelephant.ca>
>> >> wrote:
>> >>>
>> >>> Try this:
>> >>>
>> >>> --
>> >>> -- ST_DWithin_Sphere(lonlat-point, lonlat-point, radius-in-meters)
>> >>> returns boolean
>> >>> --
>> >>> -- Meters/Degree @ 60N: select 1/distance_sphere('POINT(0
>> >>> 60)','POINT(1 60)') = 1.79866403673916e-05
>> >>> --
>> >>> CREATE OR REPLACE FUNCTION ST_DWithin_Sphere(geometry, geometry,
>> >>> float8)
>> >>>        RETURNS boolean
>> >>>        AS 'SELECT $1 && ST_Expand($2,$3 * 1.79866403673916e-05) AND
>> >>> $2 && ST_Expand($1,$3 * 1.79866403673916e-05) AND
>> >>> ST_Distance_Sphere($1, $2) < $3'
>> >>>        LANGUAGE 'SQL' IMMUTABLE;
>> >>>
>> >>>
>> >>> SELECT m.id AS mid,
>> >>> m.building_i AS mb_id,
>> >>> c.id AS cid, c.building_i AS cb_id,
>> >>> m.streetaddr AS m_address,
>> >>> m.city AS m_city,
>> >>> m.state AS m_state,
>> >>> m.zip AS m_zip,
>> >>> m.zip4 AS m_zip4,
>> >>> round(CAST(
>> >>> ST_Distance_Sphere(m.the_geom, c.the_geom)
>> >>> AS numeric), 2) AS dist_meters
>> >>> FROM market_locations m, customer_locations c
>> >>> WHERE st_dwithin_sphere(m.the_geom, c.the_geom, 2414.016)
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>> >>>
>> >>
>> >
>> >
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