Hi Michael, What I'm trying to get is Concave hull of set of points.
Result of that particular concave hull algorithm (Alpha Shapes) is bunch of line segments. That part is fine, and I get bunch of line segments which outline my points just fine, however they are line segments, not polygon which is what I need. When you visually inspect those line segments, you can see big outlining polygon, lot of holes in it, lot of dangling lines, cut lines and what not. Generally polygonizer munch that lines and create polygon with holes just fine. However there is quite often situation that along the border of that (not yet formed) big polygon group of line segments form a small polygon which would in ideal case be interpreted as a hole in big polygon. Problem generally arises if one or more of line segments is shared by big and small polygon. I don't know how polygonizer works, but it would appear that those small holes get somehow created first, and line segment that belong both to hole and big polygon get 'stolen' by that small polygon, which leave big outlining polygon without one of line segments. That in turn make it not closed and basically it get thrown away. Now, what I would like to get is exact opposite, I wouldn't mind to have some small inside discarded as long as I get big outline. I hope that I explained problem better this time. If you wish I can send you .shp files with line segments and resulting polygons where is much easier to see what the problem is. Another question, is there any good user guide for JTS / NTS? I didn't find anything except class reference and some very basic user guide. Regards Dragan -- View this message in context: http://n2.nabble.com/polygonizer-and-line-strings-tp2572524p2573676.html Sent from the jts-devel mailing list archive at Nabble.com. _______________________________________________ jts-devel mailing list [email protected] http://lists.refractions.net/mailman/listinfo/jts-devel
