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<font face="Times New Roman, Times, serif">Going a step further:<br>
<br>
st_longestline(st_collect(the_geom),st_collect(the_geom))<br>
<br>
gives the longest line segment that can be drawn within the
cluster of street address points. Works for non-curved streets.
I'm still looking for a more intelligent way to thin out a polygon
to a (multi)line.<br>
<br>
Jan<br>
</font><br>
On 02/21/2012 05:27 PM, Fawcett, David (MPCA) wrote:
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<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">If
you are storing the data in PostGIS, you could possibly take
advantage of ST_Azimuth().
<a moz-do-not-send="true"
href="http://www.postgis.org/docs/ST_Azimuth.html">http://www.postgis.org/docs/ST_Azimuth.html</a><o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">It
takes two point objects as the args, but you could
potentially use the start and end points of your linestring.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D">David.<o:p></o:p></span></p>
<p class="MsoNormal"><span
style="font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">From:</span></b><span
style="font-size:10.0pt;font-family:"Tahoma","sans-serif";color:windowtext">
<a class="moz-txt-link-abbreviated" href="mailto:mapserver-users-bounces@lists.osgeo.org">mapserver-users-bounces@lists.osgeo.org</a>
[<a class="moz-txt-link-freetext" href="mailto:mapserver-users-bounces@lists.osgeo.org">mailto:mapserver-users-bounces@lists.osgeo.org</a>]
<b>On Behalf Of </b>Jan Hartmann<br>
<b>Sent:</b> Tuesday, February 21, 2012 10:23 AM<br>
<b>To:</b> <a class="moz-txt-link-abbreviated" href="mailto:mapserver-users@lists.osgeo.org">mapserver-users@lists.osgeo.org</a><br>
<b>Subject:</b> [mapserver-users] Aligning labels within
a polygon<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hi,<br>
<br>
I'm inputting lots of street address points in PostGIS, and
try to generate labels for the streets. The convex hull of the
points of a street approximate the course of the street, and I
would like to position the streetname in the middle of the
convex hull polygon, aligned to its dominant angle (the
polygons are generally quite narrow). Is there a way of doing
this with MapServer? Perhaps by thinning out the polygon to a
line, for then I can use "angle follow".<br>
<br>
Jan <o:p></o:p></p>
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