[postgis-users] Corner coordinates from Geometry

[Robert Hicks]

Great thanks! I think either ST_PointOnSurface() or ST_Centroid()
should be fine, but now I need convert the geometry string into
latitude and longitude (Sorry, I should have been more clear before
what I was ultimately looking for).

On Tue, Nov 24, 2009 at 12:40 PM, Paul Ramsey <pramsey at cleverelephant.ca> wrote:
> Ah, POINT(avg(X), avg(Y))...
>
> On Tue, Nov 24, 2009 at 9:38 AM, Kevin Neufeld <kneufeld at refractions.net> wrote:
>> Maxime van Noppen wrote:
>>>
>>> Paul Ramsey wrote:
>>>>
>>>> Use ST_Centroid() then. It's just the mid-point of the bbox, so it's
>>>> fast to calculate.
>>>
>>> It might be outside the polygon though.
>>>
>>
>> In which case, if it matters, use ST_PointOnSurface().
>>
>> Paul, just a clarification, I believe centroid calculates the geometric
>> centre of a geoemtry or "centre of mass" and not the mid-point of the bbox.
>>  Here are a few pictorial examples:
>> http://postgis.org/documentation/manual-1.5SVN/ST_Centroid.html
>>
>> -- Kevin
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users at postgis.refractions.net
>> http://postgis.refractions.net/mailman/listinfo/postgis-users
>>
> _______________________________________________
> postgis-users mailing list
> postgis-users at postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
>



-- 
web http://www.hyxspace.com
aim hyx1138