[postgis-users] Spheroid Question

Dan Phillips danp at americanclearinghouse.com
Fri Jun 24 12:45:50 PDT 2005


Much better! (29 seconds)

Thanks Paul,

Dan

-----Original Message-----
From: postgis-users-bounces at postgis.refractions.net
[mailto:postgis-users-bounces at postgis.refractions.net]On Behalf Of Paul
Ramsey
Sent: Friday, June 24, 2005 3:32 PM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] Spheroid Question


Unless you are desperate to get the correct answer to the n'th degree of
accurace, try distance_sphere, it's 10 times faster.

Dan Phillips wrote:
> Okay, this works. It's just really slow (~40 minutes). Any suggestions on
> speeding this up?
>
> SELECT
>   CRID,
>   distance_spheroid(centroid(the_geom),
>   setSRID(makepoint(-72.607912, 42.058052),4326),
>   'SPHEROID["GRS_1980",6378137,298.257222101]') as distance
> FROM crrts
> WHERE
>   the_geom && expand(setSRID(makepoint(-72.607912, 42.058052),4326),2000)
>   AND distance_spheroid(centroid(the_geom),
>   setSRID(makepoint(-72.607912, 42.058052),4326),
>   'SPHEROID["GRS_1980",6378137,298.257222101]')<2000 ;
>
> Thanks,
>
> Dan
>
> -----Original Message-----
> From: postgis-users-bounces at postgis.refractions.net
> [mailto:postgis-users-bounces at postgis.refractions.net]On Behalf Of
> strk at refractions.net
> Sent: Friday, June 24, 2005 11:39 AM
> To: PostGIS Users Discussion
> Subject: Re: [postgis-users] Spheroid Question
>
>
> On Fri, Jun 24, 2005 at 11:36:27AM -0400, Dan Phillips wrote:
>
>>Thanks Jeff & Paul. That was the problem.
>>
>>Now I'm getting "ERROR:  Operation on two geometries with different SRIDs"
>>
>>I assume this is because I'm not setting the SRID for my makepoint(). How
>
> do
>
>>I do this to make it match the SRID (4326) of my 'crrts' table?
>
>
> Use the setSRID() function:
> setSRID(makepoint())
> --strk;
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