Hi Martin I obtained good performance with the new buffer Here are some extensive tests :
* Old buffer New buffer*308 polygons - buffer 10 : 4 s --> 5 s 308 polygons - buffer 100 : 51 s --> 10 s
20507 linestrings - b 10 : 23 s --> 21 s 20507 linestrings - b 10 : 367 s --> 70 s 6444 points - 10/100/1000 : 3 s --> 2 sPerformance are constant for point buffer (old, new, small buffers, large buffers)
Performance do not change much between old and new buffer for small buffersPerformance improve greatly for large buffer (considering Larry's test, I think the ratio is even higher for larger buffers)
I compared total resulting surfaces with the jump plugin (statistic for the layer)
For linestring, I did not notice any differencesame area +/- 0.000005 m2 for a total of 2 000 000 000 m2 (let's say the same)
For polygon, I noticed a small difference same area +/- 23000 m2 for a total of 5 000 000 000 m2The image show how the new buffer has simplified the geometry (the old buffer is marked ith big points, distance between the two buffers are about 0.3 m for a buffer of 100 m)
Michaël Martin Davis a écrit :
Good to hear, Larry - thanks for testing this. Larry Becker wrote:Congratulations Martin! Buffering 41 complex aircraft features took 83 seconds with your old algorithm, and only 2 seconds using your new one. I could find no anomalies.regards, Larry BeckerOn Wed, Oct 8, 2008 at 4:23 PM, Martin Davis <[EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]>> wrote:JTS'ers, As you may have experienced, buffering in JTS currently has some performance challenges in situations involving large buffer distances. I'm excited to say that I've implemented some code enhancements which *dramatically* improve buffer performance in these cases (as well as providing an overall improvement). I've tested this code as extensively as I can, and am pretty confident that it is robust and accurate. But it's always good to have other people beat on it as well! So, is anyone out there ready, able and willing to test out the new buffering code? Ideally this would be someone who has a application which uses buffering in a significant way, and which allows determining the performance and correctness characteristics effectively. I'm looking for feedback to either confirm that this really is an improvement, or some test cases which reveal issues if there are any. If you're able to help out, you can either download and build the codebase from CVS, or I've built an alpha release of JTS 1.10 which is available here: http://tsusiatsoftware.net/jts/files/jts-1.10-alpha.zip Thanks - Martin -- Martin Davis Senior Technical Architect Refractions Research, Inc. (250) 383-3022 _______________________________________________ jts-devel mailing list [email protected] <mailto:[email protected]> http://lists.refractions.net/mailman/listinfo/jts-devel -- http://amusingprogrammer.blogspot.com/ ------------------------------------------------------------------------ _______________________________________________ jts-devel mailing list [email protected] http://lists.refractions.net/mailman/listinfo/jts-devel
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