<div class="gmail_quote"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">Ok,<div><br><div>basically I have table location(id int, point geometry(POINT)) and function getallpointsincircle(longitude, latitude, radius) which gives set of internal indexes from location table if point in table is in the radius of parameters of function. Inside function I am using st_dwithin </div>
<div><pre><span>declare</span>
t2_row <span>location</span>%rowtype;
po geometry;
<span>begin</span>
po:=st_geomfromtext(<span>'POINT('</span>||lon||<span>' '</span>||lat||<span>')'</span>,3044);
<span>for</span> t2_row <span>in</span> <span>select</span> * <span>from</span> <span>location</span>
loop
if st_dwithin(t2_row.point,po, radius) <span>is</span> <span>true</span>
<span>then</span> <span>return</span> <span>next</span> <a href="http://t2_row.id" target="_blank">t2_row.id</a>;
<span>end</span> if;
<span>end</span> loop;
<span>return</span>;
<span>end</span>;</pre><div><br></div>idst_astext
<div style="text-align:right">12</div>POINT(7.4545 44)
<div style="text-align:right">13</div>POINT(7.49785 44)
<div style="text-align:right">14</div>POINT(7.6845 44)
<div style="text-align:right">15</div>POINT(7.96311 44)
<div style="text-align:right">16</div>POINT(55.859755 9.847419)</div><div><br></div><div>these are test values in location table, as you can see point(16) has measured coords, others are bogus. </div><div>Now, when I execute my function select getallpointsincircle(56.162882,10.203944,45000.0), all the indexes are returned. Approximately the distance between these places is 40 km. But when I exchange 45000.0 with 0.46 i will get proper index(16 in this case).</div>
<div><br></div><div><br></div><div><br><div class="gmail_quote">2011/3/7 Mike Toews <span dir="ltr"><<a href="mailto:mwtoews@gmail.com" target="_blank">mwtoews@gmail.com</a>></span><div><div></div><div class="h5"><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
You are using EPSG:3044, correct? <a href="http://spatialreference.org/ref/epsg/3044/" target="_blank">http://spatialreference.org/ref/epsg/3044/</a><div><br></div><div><a href="http://spatialreference.org/ref/epsg/3044/" target="_blank"></a>This projection has units of metres. ST_DWithin and related functions use the same units of length as defined in the projection, which in this case is metres, not degrees. You may need to elaborate with an example.</div>
<div><br></div><div><font color="#888888">-Mike</font><div><div></div><div><br><br><div class="gmail_quote">On 7 March 2011 23:41, michal nagy <span dir="ltr"><<a href="mailto:lachim1989@gmail.com" target="_blank">lachim1989@gmail.com</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
Well, it sitll does not solve my problem. As I said I am using geometry(planar) with SRID 3044, where units are degrees, therefore when using st_dwithin will still take input in degrees.<br><br><div class="gmail_quote">2011/3/7 Paragon Corporation <span dir="ltr"><<a href="mailto:lr@pcorp.us" target="_blank">lr@pcorp.us</a>></span><br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div><div></div><div>
<div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2" face="Arial">Use ST_DWithin instead. <a href="http://www.postgis.org/documentation/manual-1.5SVN/ST_DWithin.html" target="_blank">http://www.postgis.org/documentation/manual-1.5SVN/ST_DWithin.html</a></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2" face="Arial"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2" face="Arial">We cover this topic in detail in the first chapter of our book
which is a free download.</font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2" face="Arial"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2" face="Arial"><a href="http://www.postgis.us/chapter_01" target="_blank">http://www.postgis.us/chapter_01</a></font></span></div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2" face="Arial"></font></span> </div>
<div dir="ltr" align="left"><span><font color="#0000ff" size="2" face="Arial">Leo and Regina</font></span></div><br>
<div dir="ltr" lang="en-us" align="left">
<hr>
<font size="2" face="Tahoma"><b>From:</b>
<a href="mailto:postgis-users-bounces@postgis.refractions.net" target="_blank">postgis-users-bounces@postgis.refractions.net</a>
[mailto:<a href="mailto:postgis-users-bounces@postgis.refractions.net" target="_blank">postgis-users-bounces@postgis.refractions.net</a>] <b>On Behalf Of
</b>michal nagy<br><b>Sent:</b> Monday, March 07, 2011 2:29 AM<br><b>To:</b>
<a href="mailto:postgis-users@postgis.refractions.net" target="_blank">postgis-users@postgis.refractions.net</a><br><b>Subject:</b> [postgis-users] meters
to degrees<br></font><br></div><div><div></div><div>
<div></div><font size="3"><span><br></span></font>
<table cellspacing="0" cellpadding="3">
<tbody>
<tr>
<td></td></tr></tbody></table><font size="4"><tt><font color="#1a1a1a">Hello everyone,</font></tt><br><br><tt><font color="#1a1a1a">I am
new to Postgres and PostGIS. I have encountered one problem, that
I</font></tt><br><tt><font color="#1a1a1a">can not deal with.I have table with
various points that have SRID=3044,</font></tt><br><tt><font color="#1a1a1a">which
should be UTM zone including Jutland. I have created function
to</font></tt><br><tt><font color="#1a1a1a">loop through all points in table and
check if they are within given</font></tt><br><tt><font color="#1a1a1a">radius(using geometry and function st_point_inside_circle). Now to
the</font></tt><br><tt><font color="#1a1a1a">problem, for some reason
st_point_inside_circle takes radius in degrees,</font></tt><br><tt><font color="#1a1a1a">which is very inconvenient for me. I would really need to
change to</font></tt><br><tt><font color="#1a1a1a">metres. If anyone has a
suggestion, pls let me know.</font></tt><br><br><tt><font color="#1a1a1a">Thank
you for help</font></tt><br><br><tt><font color="#1a1a1a">Michal</font></tt></font> </div></div></div>
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