[postgis-users] Spheroid Question

[Paul Ramsey]

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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