[mkgmap-dev] [Patch v5] LocationHook with new QuadtreeFrom GerdP gpetermann_muenchen at hotmail.com on Wed Jan 18 20:08:03 GMT 2012
Hi WanMil, I have no special reason for using the nano second timer. I tried it because I noticed that the mili second timer is very inaccurate. I got the impression that nano seconds are more precise, but of course the only usable value is a mean value of long running tasks. ciao, Gerd WanMil wrote > > Hi Gerd, > > thanks for your further patch. > I have a question about it: I see that you measure timings with nano > second timer. I am quite sure that such accuracy is not given in such > time measurements and often lead to wrong results. Do you really require > that accuracy? In such a case I am sure that you can stop coding because > there would be nothing more to improve so that the total runtime > decreases. It would be just a matter of fortune. > > I think the only reasonable indicator is to measure the sum of the > overall LocationHook timing for several tiles (>20). If that decreases > significantly there is an improvement. > > WanMil > > > >> Hi WanMil, >> >> attached is the new version of the patch, now based on r2171. >> I've invested a lot of time testing the result of LocationHook, I think >> it >> is always as good or better than trunk. >> I will now try to add the quadtree to the preparer. >> >> Changes: >> - build.xml with includeantruntime="false" to calm down ant >> - added a few debugging aids and printout of complete runtime >> - performance improvements in add() and merge() methods >> - if a search in the nodes of the quadtree doesn't find the area, >> additional >> searches are performed for points >> in the neighbourhood >> - for ways, the mid point is searched first. If the search returns null, >> all >> points are searched from the first one until a result is found. With my >> test >> data, quadtree never returned null, so this last loop is probably only >> needed when boundary data is very incomplete. >> >> http://gis.638310.n2.nabble.com/file/n7199763/locationHook_speedup_v5.patch >> locationHook_speedup_v5.patch >> >> ciao, >> Gerd >> >> -- >> View this message in context: >> http://gis.638310.n2.nabble.com/Patch-v5-LocationHook-with-new-Quadtree-tp7199763p7199763.html >> Sent from the Mkgmap Development mailing list archive at Nabble.com. >> _______________________________________________ >> mkgmap-dev mailing list >> mkgmap-dev at .org >> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev > > _______________________________________________ > mkgmap-dev mailing list > mkgmap-dev at .org > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev > -- View this message in context: http://gis.638310.n2.nabble.com/Patch-v5-LocationHook-with-new-Quadtree-tp7199763p7201442.html Sent from the Mkgmap Development mailing list archive at Nabble.com.
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