[mkgmap-dev] [PATCH V1] Idea for minor speed improvement for boundary preprocessingFrom GerdP gpetermann_muenchen at hotmail.com on Fri Feb 24 14:12:24 GMT 2012
Hi WanMil, this was a very good hint :-) Time for african boundaries was 250 secs with /branch/performance/r2225, 267 secs with trunk, and with this patch it is now 152 secs - use simple quadtree in BoundarySaver.splitArea() - add try/catch in BoundaryPreparer.run() to allow e.g. usage of assert. Without that, an assertion was handled by the threading routines and caused program stop without any message. Please double check this, I am still not so experienced with try+catch and wrong placed Ciao, Gerd http://gis.19327.n5.nabble.com/file/n5512906/splitArea_v1.patch splitArea_v1.patch WanMil wrote > > Hi Gerd, > > boundary preprocessing takes quite a lot of time. That's not a big > problem because it's performed only by some people who publish their > results. > > But I think some speed improvements would not be bad anyhow?! > > While preprocessing asia and america I go an idea. The area of a > boundary is splitted into the raster. But each time the complete area is > intersected to the raster. In case an area is big and/or complex > (boundary of russia, USA, canada etc.) this takes a long time. It would > be possible first to cut the area into smaller pieces (columns or rows > of the raster) and then do the final cut to the raster. Maybe this saves > time because the column or row areas should be less complex. > > What do you think? > > WanMil > _______________________________________________ > mkgmap-dev mailing list > mkgmap-dev at .org > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev > -- View this message in context: http://gis.19327.n5.nabble.com/PATCH-V1-Idea-for-minor-speed-improvement-for-boundary-preprocessing-tp5512906p5512906.html Sent from the Mkgmap Development mailing list archive at Nabble.com.
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