FYI, as of r3078 the mis-port is fixed in GEOS. Still interested in the result after self-noding. Thanks !
--strk; On Thu, Jul 01, 2010 at 10:59:12PM +0200, strk wrote: > On Mon, Jun 21, 2010 at 09:13:16AM -0700, Martin Davis wrote: > > strk, > > > > The JTS Developer's Guide is a bit confusing. The geometry given in the > > example is NOT the geometry depicted in the illustration. (This is a > > doc bug - but I"m not sure if and when I can fix it). > > > > When I run the geometry below in JTS I get: > > > > Polygons: > > GEOMETRYCOLLECTION ( > > POLYGON ((189 98, 83 187, 185 221, 325 168, 189 98)), > > POLYGON ((185 221, 88 275, 180 316, 292 281, 185 221))) > > > > Dangles: > > MULTILINESTRING ((185 221, 100 100), > > (0 0, 10 10)) > > > > I believe this is the expected result. > > Uhm, that's w/out self-noding, right ? > > --strk; > > > > > > Hope that helps > > > > Martin > > > > strk wrote: > > >Martin, I'm adding a testcase for the Polygonizer using example from : > > >"JTS Developer's Guide, Chapter 6 - Polygonization" > > > > > >Here's the input, represented as a collection: > > > > > >GEOMETRYCOLLECTION( > > > LINESTRING(0 0, 10 10), > > > LINESTRING(185 221, 100 100), > > > LINESTRING(185 221, 88 275, 180 316), > > > LINESTRING(185 221, 292 281, 180 316), > > > LINESTRING(189 98, 83 187, 185 221), > > > LINESTRING(189 98, 325 168, 185 221)) > > >) > > > > > >When passing it into the Polygonizer class I get > > >2 rings, no cut or invalid edges and 3 dangles. > > >Also notable is that of the 3 dangles, 2 are identical > > >and specificall are the isolated edge (first geometry > > >in the collection). > > > > > >The example in the guide suggests the rings should > > >be 3 instead, and that there should be one cut > > >edge (represented in blue) and 2 dangles > > >the red ones. > > > > > >Does it sound as a bug in GEOS or does JTS give the > > >same results ? > > > > > >Note that forcing proper noding using the union trick > > >does give the 3 expected rings, but still lacks the > > >cut edge and duplicates the dangle. > > > > > >Thanks in advance. > > > > > >--strk; > > > > > > () Free GIS & Flash consultant/developer > > > /\ http://strk.keybit.net/services.html > > > > > > > -- > > Martin Davis > > Senior Technical Architect > > Refractions Research, Inc. > > (250) 383-3022 > > -- > > () Free GIS & Flash consultant/developer > /\ http://strk.keybit.net/services.html > _______________________________________________ > geos-devel mailing list > geos-devel@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/geos-devel -- () Free GIS & Flash consultant/developer /\ http://strk.keybit.net/services.html _______________________________________________ geos-devel mailing list geos-devel@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/geos-devel