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List:       postgis-users
Subject:    Re: [postgis-users] Distance from point inside polygon to closest
From:       "Chris Story" <kc5hhq () gmail ! com>
Date:       2007-07-31 11:40:37
Message-ID: 424bf9650707310440k69dc218encbca2bb02ed8a087 () mail ! gmail ! com
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Michael,
ExteriorRing doesn't seem to work. Maybe this is due to the_geom being a
multi-polygon? This returns something, but I'm not sure if it is correct.
Could anyone tell me?


SELECT distance(transform(GeomFromText( 'POINT(-81.0571731786471
28.0183613937886 )', 4326 ),utmzone(GeomFromText( 'POINT(-81.0571731786471
28.0183613937886 )', 4326 ))),
boundary(transform(the_geom,utmzone(GeomFromText( 'POINT(-81.0571731786471
28.0183613937886)', 4326 ))))) FROM "S_FIRM_PAN" where gid = 743;

On 7/30/07, Michael Fuhr <mike@fuhr.org> wrote:
>
> On Mon, Jul 30, 2007 at 08:43:34PM -0500, Chris Story wrote:
> > I am attempting to determine the distance from a point inside a polygon
> > to the edge of the polygon. How can I achieve this?
>
> Have you tried distance(point_geom, exteriorring(poly_geom))?
>
> --
> Michael Fuhr
> _______________________________________________
> postgis-users mailing list
> postgis-users@postgis.refractions.net
> http://postgis.refractions.net/mailman/listinfo/postgis-users
>



-- 
Thank you,

Chris Story

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Michael,<br>ExteriorRing doesn&#39;t seem to work. Maybe this is due to the_geom \
being a multi-polygon? This returns something, but I&#39;m not sure if it is correct. \
Could anyone tell me?<br><br><br>SELECT distance(transform(GeomFromText( &#39;POINT(- \
81.0571731786471 28.0183613937886 )&#39;, 4326 ),utmzone(GeomFromText( \
&#39;POINT(-81.0571731786471 28.0183613937886 )&#39;, 4326 ))), \
boundary(transform(the_geom,utmzone(GeomFromText( &#39;POINT(-81.0571731786471 \
28.0183613937886 )&#39;, 4326 ))))) FROM &quot;S_FIRM_PAN&quot; where gid = \
743;<br><br><div><span class="gmail_quote">On 7/30/07, <b \
class="gmail_sendername">Michael Fuhr</b> &lt;<a \
href="mailto:mike@fuhr.org">mike@fuhr.org</a>&gt; wrote: </span><blockquote \
class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt \
0pt 0.8ex; padding-left: 1ex;">On Mon, Jul 30, 2007 at 08:43:34PM -0500, Chris Story \
wrote:<br>&gt; I am attempting to determine the distance from a point inside a \
polygon <br>&gt; to the edge of the polygon. How can I achieve this?<br><br>Have you \
tried distance(point_geom, exteriorring(poly_geom))?<br><br>--<br>Michael \
Fuhr<br>_______________________________________________<br>postgis-users mailing list \
<br><a href="mailto:postgis-users@postgis.refractions.net">postgis-users@postgis.refractions.net</a><br><a \
href="http://postgis.refractions.net/mailman/listinfo/postgis-users">http://postgis.refractions.net/mailman/listinfo/postgis-users
 </a><br></blockquote></div><br><br clear="all"><br>-- <br>Thank you,<br><br>Chris \
Story<br><br>



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