[postgis-users] Representing this polygon.

Paul Ramsey pramsey at cleverelephant.ca
Wed Aug 13 13:15:31 PDT 2008


PS : The whole song-and-dance with the ST_Transform is so I can create
a proper circular buffer using a metric distance (meters = 1609 *
miles) around a geographic point (degrees).

On Wed, Aug 13, 2008 at 1:14 PM, Paul Ramsey <pramsey at cleverelephant.ca> wrote:
> Theoretically, with a CURVEPOLYGON. Practically, by stroking that arc
> so it's a standard POLYGON.
>
> ST_Union(
> ST_Transform(ST_Buffer(ST_Transform(ST_GeomFromText('POINT(-115.79222222
> 49.955)', 4269),26910),50*1609),4269),
> ST_GeomFromText('POLYGON((-123.25 56, -119 53.4, -116.-8472222
> 50.32638888, -115.79222222 49.955, -115.14722222 49.9625, -115.1375
> 49.5, -115.49972222 49.00055555, 123.25 56))',4269)
> )
>
> I hate DMS notation, I hate it so...
>
> P.
>
> On Wed, Aug 13, 2008 at 12:50 PM, Blake Crosby <me at blakecrosby.com> wrote:
>> Given this definition, how would one represent this polygon in PGSQL:
>>
>> N56°00'00.00" W123°15'00.00" to
>> N53°24'00.00" W119°00'00.00" to
>> N50°19'35.00" W116°05'05.00" thence clockwise along the arc of a circle of
>> 25 miles radius centred on
>> N49°57'18.00" W115°47'32.00" to
>> N49°57'45.00" W115°08'50.00" to
>> N49°30'00.00" W115°08'15.00" to
>> N49°00'02.00" W115°29'59.00" point of beginning
>>
>> Blake
>> _______________________________________________
>> postgis-users mailing list
>> postgis-users at postgis.refractions.net
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>>
>



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