Re: [jts-devel] Re: what shall I do If I get a topology exception in union op?
2009/3/19 Martin Davis : > No, I don't use this technique. It looks pretty complicated! That's reassuring. Ironic given the title :-) Michael ___ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel
Re: [jts-devel] Re: what shall I do If I get a topology exception in union op?
No, I don't use this technique. It looks pretty complicated! And I have never seen any implementation examples on the web (which is the case for 90% of the papers out there, of course). For predicates I use the technique of exact determinant sign evaluation by Devillers et al. For robustness of line arrangment computation I use a snap-rounding approach (see Hobby and others). M Michael Bedward wrote: 2009/3/18 Martin Davis : So it doesn't need debugging - it needs some brilliant new thinking! Sounds like what I think about most of my code... Out of interest Martin, do you use anything like the approach described here... Edelsbrunner & Mucke (1990) Simulation of simplicity: a technique to cope with degenerate cases in geometric algorithms. http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.38.5997 I've been trying to understand it. Michael ___ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel -- Martin Davis Senior Technical Architect Refractions Research, Inc. (250) 383-3022 ___ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel
Re: [jts-devel] Re: what shall I do If I get a topology exception in union op?
2009/3/18 Martin Davis : > So it doesn't need debugging - it needs some brilliant new thinking! Sounds like what I think about most of my code... Out of interest Martin, do you use anything like the approach described here... Edelsbrunner & Mucke (1990) Simulation of simplicity: a technique to cope with degenerate cases in geometric algorithms. http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.38.5997 I've been trying to understand it. Michael ___ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel
Re: [jts-devel] Re: what shall I do If I get a topology exception in union op?
No, unfortunately there's no debugging procedure. This situation is due to a known limitation in the current overlay algorithm design. So it doesn't need debugging - it needs some brilliant new thinking! Thanks for the dataset Good that you found a workaround. Martin Stefan Steiniger wrote: Hei Martin, thank you for your answer. So it seems there is no "debugging" procedure and instead you suggest a data simplification. I will send you the dataset in a personal email. I have actually now taken a different approach by splitting the datasets and using the Symmetric Difference Function in ArcGIS. stefan ___ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel -- Martin Davis Senior Technical Architect Refractions Research, Inc. (250) 383-3022 ___ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel
[jts-devel] Re: what shall I do If I get a topology exception in union op?
Hei Martin, thank you for your answer. So it seems there is no "debugging" procedure and instead you suggest a data simplification. I will send you the dataset in a personal email. I have actually now taken a different approach by splitting the datasets and using the Symmetric Difference Function in ArcGIS. stefan ___ jts-devel mailing list jts-devel@lists.jump-project.org http://lists.refractions.net/mailman/listinfo/jts-devel
