Hi Doug,
If your point is in a table points and your states are in a table states and
your distances are in feet
then one way might be something like:
select states.stateabbrev, st_distance(states.geom,points.geom)/5280
from points, states
where points.point_id = your_PA_point_id
and stateabbrev in ('OH','MD',''WV','VA')
order by st_distance(states.geom,points.geom)
If your point is an xy location then similarly (using example point in Greene
County)
select states.stateabbrev,
st_distance(states.geom,makepoint(1263197,192349))/5280
from states
where stateabbrev in ('OH','MD',''WV','VA')
order by st_distance(states.geom,makepoint(1263197,192349))
If you are talking about the SW corner point on the PA Boundary then you'll
need to get the
point on PA Boundary nearest the SW point (always the first point I believe)
on the exteriorring of the envelope of the PA Boundary which would be:
select
st_line_interpolate_point(st_exteriorring(st_geometryn(geom,1)),st_line_locate_point(st_exteriorring(st_geometryn(geom,1)),st_pointn(st_exteriorring(st_envelope(geom)),1)))
from states where stateabbrev = 'PA'
and use that point in the query(s) above. There are other ways, probably
better ways too.
-Eric
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of Doug Fischer
Sent: Tuesday, September 09, 2008 10:55 AM
To: PostGIS Users Discussion
Subject: Re: [postgis-users] list of the closest borders
Sorry but I just noticed that I made an error in my post. What I meant to say
was the SW corner of PA and in the table the distance to PA should be 0 because
the Point is in PA.
Thanks,
Doug
On Sep 9, 2008, at 8:52 AM, Doug Fischer wrote:
I am new to GIS / PostGIS so please forgive me if this is a simple question.
Assuming that I have a database populated with all of the proper data, I need
to do determine a list of the closest borders from a point including distances.
ex.
If I have a point located in the SE corner of PA, I would like to run a query
that will return a list containing something like the following:
Border
Distance in miles
PA
A
OH
B
MD
C
WV
D
VA
E
Is there a function in PostGIS that can do this type of thing? Does anyone have
an example?
Thank you very much.
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