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<DIV dir=ltr align=left><SPAN class=627193022-15012015><FONT size=4>I'd prefer
just one function with a default distance argument of 0.</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=627193022-15012015><FONT
size=4></FONT></SPAN> </DIV>
<DIV dir=ltr align=left><SPAN class=627193022-15012015><FONT
size=4>Thanks,</FONT></SPAN></DIV>
<DIV dir=ltr align=left><SPAN class=627193022-15012015><FONT
size=4>Regina</FONT></SPAN></DIV><BR>
<DIV lang=en-us class=OutlookMessageHeader dir=ltr align=left>
<HR tabIndex=-1>
<FONT size=2 face=Tahoma><B>From:</B> postgis-devel-bounces@lists.osgeo.org
[mailto:postgis-devel-bounces@lists.osgeo.org] <B>On Behalf Of </B>Paul
Ramsey<BR><B>Sent:</B> Thursday, January 15, 2015 5:23 PM<BR><B>To:</B> PostGIS
Development Discussion<BR><B>Subject:</B> Re: [postgis-devel] Geometry
clustering functions<BR></FONT><BR></DIV>
<DIV></DIV>
<DIV id=bloop_customfont
style="FONT-SIZE: 13px; FONT-FAMILY: Helvetica,Arial; COLOR: ; MARGIN: 0px">Do
we want to go the “Accum” naming route, or introduce a “cluster” work?</DIV>
<DIV id=bloop_customfont
style="FONT-SIZE: 13px; FONT-FAMILY: Helvetica,Arial; COLOR: ; MARGIN: 0px"><BR></DIV>
<DIV id=bloop_customfont
style="FONT-SIZE: 13px; FONT-FAMILY: Helvetica,Arial; COLOR: ; MARGIN: 0px"><SPAN
style="FONT-FAMILY: monospace">ST_ClusterWithinDistance</SPAN></DIV>
<DIV id=bloop_sign_1421360500968449024 class=bloop_sign>
<DIV><BR></DIV>
<DIV>Also, since the intersecting cluster is just the withindistance with a
tolerance of zero, would having just one function be good or bad?</DIV>
<DIV><BR></DIV>
<DIV>P.</DIV>
<DIV><BR></DIV>-- <BR>Paul Ramsey<BR>http://cleverelephant.ca
<DIV>http://postgis.net </DIV>
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</DIV><BR>
<P style="COLOR: #000">On January 15, 2015 at 2:07:24 PM, Daniel Baston (<A
href="mailto:dbaston@gmail.com">dbaston@gmail.com</A>) wrote:</P>
<BLOCKQUOTE class=clean_bq type="cite"><SPAN>
<DIV>
<DIV></DIV>
<DIV>
<DIV dir=ltr>Glad to hear there is some interest! I posted some ideas
to <A
href="http://trac.osgeo.org/postgis/wiki/DevClusteringFunctions">http://trac.osgeo.org/postgis/wiki/DevClusteringFunctions</A>
<DIV><BR></DIV>
<DIV>Thanks,</DIV>
<DIV>Dan</DIV></DIV>
<DIV class=gmail_extra><BR>
<DIV class=gmail_quote>On Thu, Jan 15, 2015 at 12:28 PM, Paul Ramsey <SPAN
dir=ltr><<A href="mailto:pramsey@cleverelephant.ca"
target=_blank>pramsey@cleverelephant.ca</A>></SPAN> wrote:<BR>
<BLOCKQUOTE class=gmail_quote
style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid">
<DIV style="WORD-WRAP: break-word">
<DIV
style="FONT-SIZE: 13px; FONT-FAMILY: Helvetica,Arial; COLOR: ; MARGIN: 0px">Daniel,</DIV>
<DIV
style="FONT-SIZE: 13px; FONT-FAMILY: Helvetica,Arial; COLOR: ; MARGIN: 0px">This
is interesting stuff, could you post some example function signature and
input/output pictures on the wiki so we can do a little design review. I
thing it’s very exciting and am very positive about it.</DIV>
<DIV
style="FONT-SIZE: 13px; FONT-FAMILY: Helvetica,Arial; COLOR: ; MARGIN: 0px"><SPAN
class=HOEnZb><FONT color=#888888><BR></FONT></SPAN></DIV>
<DIV
style="FONT-SIZE: 13px; FONT-FAMILY: Helvetica,Arial; COLOR: ; MARGIN: 0px"><SPAN
class=HOEnZb><FONT color=#888888>P</FONT></SPAN></DIV>
<DIV>
<DIV><SPAN class=HOEnZb><FONT color=#888888><BR></FONT></SPAN></DIV><SPAN
class=HOEnZb><FONT color=#888888>-- <BR>Paul Ramsey<BR><A
href="http://cleverelephant.ca"
target=_blank>http://cleverelephant.ca</A></FONT></SPAN>
<DIV><SPAN class=HOEnZb><FONT color=#888888><A href="http://postgis.net"
target=_blank>http://postgis.net</A></FONT></SPAN></DIV></DIV>
<DIV>
<DIV class=h5><BR>
<P style="COLOR: #000">On January 15, 2015 at 4:14:44 AM, Daniel Baston (<A
href="mailto:dbaston@gmail.com" target=_blank>dbaston@gmail.com</A>)
wrote:</P></DIV></DIV>
<BLOCKQUOTE type="cite">
<DIV>
<DIV>
<DIV>
<DIV class=h5>
<DIV dir=ltr>
<DIV>
<DIV>
<DIV>
<DIV><SPAN>Hello,<BR><BR>I'm working on a couple of C-language functions
to solve some clustering problems I frequently face in PostGIS. I'm
wondering if there may be any level of interest in including such
functions in the project? I would be happy to flesh these out to
include the error-handling and unit-testing that would be
required.<BR><BR></SPAN></DIV><SPAN>Function #1 takes a GeometryCollection
and returns the same geometries, re-aggregated into groups of
interconnected geometries (solving a question I posted about at <A
href="http://gis.stackexchange.com/q/94203"
target=_blank>http://gis.stackexchange.com/q/94203</A>
)<BR><BR></SPAN></DIV>
<DIV><SPAN>(Internally this builds an STRtree using GEOS and uses a
union-find structure to identify connected components....as an aside, I am
wondering if there is some way to take advantage of a database spatial
index that may already exist)<BR></SPAN></DIV>
<DIV><SPAN><BR></SPAN></DIV></DIV><SPAN>Function #2 (not written) would
solve a related problem - we want to take a set of points and return a set
of MultiPoints, where each point in a MultiPoint is within distance X of
some other point in the
MultiPoint.<BR><BR></SPAN></DIV><SPAN>Thanks,<BR>Dan<BR></SPAN></DIV></DIV></DIV><SPAN><SPAN>_______________________________________________<BR>postgis-devel
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target=_blank>http://lists.osgeo.org/cgi-bin/mailman/listinfo/postgis-devel</A></SPAN></SPAN></DIV></DIV></BLOCKQUOTE></DIV><BR>_______________________________________________<BR>postgis-devel
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