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<TITLE>RE: [mapserver-users] How to avoid point from overlaying one another</TITLE>
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<P><FONT SIZE=2>Steve,<BR>
My $0.02 on this isn't really a mapserver specific solution, so it may be of limited interest to you. I played around with a little PostGIS view/query to dynamically cluster points of multiple individuals representing residents of a household. What I came up with was a formula that essentially built them in a spiral around the centroid of the point. Perhaps you might use a similar approach for a certain maxextent/minextent before you could be certain that a user was zoomed in enough to view all points successfully.<BR>
<BR>
The description and a sample dataset is here:<BR>
<A HREF="http://soulswimmer.dynalias.net/gis/psql/visualize_demo.sql.txt">http://soulswimmer.dynalias.net/gis/psql/visualize_demo.sql.txt</A><BR>
<BR>
Good luck,<BR>
r.b.<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: mapserver-users-bounces@lists.osgeo.org on behalf of Stephen Woodbridge<BR>
Sent: Mon 6/2/2008 2:31 PM<BR>
To: mapserver-users<BR>
Cc: <BR>
Subject: [mapserver-users] How to avoid point from overlaying one another<BR>
<BR>
Hi all,<BR>
<BR>
I have a point layer that is displaying points of interest (POI). Each<BR>
POI has a classification that I use with a class expression to display a<BR>
different icon image for the POI. I some cities there are so many POIs<BR>
in a small spatial area that they all pile on top of one another and<BR>
make a mess.<BR>
<BR>
Is there anyway to do collision avoidance with the points?<BR>
<BR>
I can change the layer TYPE to ANNOTATION which will thin them based on<BR>
the ability to label them but it does not control whether they will be<BR>
overlapped anyway, just assures that the symbol will only get drawn IF<BR>
the label will fit.<BR>
<BR>
Thoughts?<BR>
-Steve W<BR>
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