Hi, I have been using gdal_grid to interpolate LiDAR data for some time now. This would be a typical command:
gdal_grid -l P0344_sol2004_XYZI_MTM8_CGVD28_150529 -txe 348733.0 401135.0 -tye 5568587.0 5773796.0 -a nearest:radius1=3.0:radius2=3.0:angle=0.0:nodata=0.0 -outsize 52402.0 205209.0 -of GTiff H:/Nicolas/pytemp/OutPut\P0344_sol2004_XYZI_MTM8_CGVD28_150529.vrt H:/Nicolas/pytemp/OutPut\P0344_sol2004_XYZI_MTM8_CGVD28_150529.tif --config GDAL_NUM_THREADS ALL_CPUS As you can see, this is a huge raster and the csv. file (Pointed with a .vrt) contains over a billion points. I am trying to do this in one shot to avoid boundary effects. (I know I can split this .csv file into smaller bits and make this more efficient). The computer I am using has 12 cores, 64BG of memory (smaller than the csv file) and a 1TB pcie solid state drive. It should manage the task but it has been running for 5 days with less than 10% done). I have access to a super computer with gdal if all else fails. This is my question. The "--config GDAL_NUM_THREADS ALL_CPUS" or "--config GDAL_NUM_THREADS 12" does not seem to work with the nearest neighbor algorithm. (It seem to work with the -a count command) If I use this on a smaller data set, I see no difference in speed or cpu usage between using the "ALL_CPUS" or not using this switch. Is this a bug or simply a limitation of the nearest neighbor algorithm? I don't want to move this to a super computer if it will not multi-thread properly. Thanks, Nicolas Cadieux (Gdal1.11.2 downloaded with OSGEO4W 64bit install with QGIS 2.8 on windows 7_64) I use GDAL from the command line not from QGIS. Nicolas Cadieux M.Sc. Les Entreprises Archéotec inc. 8548, rue Saint-Denis Montréal H2P 2H2 Téléphone: 514.381.5112 Fax: 514.381.4995 www.archeotec.ca _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org http://lists.osgeo.org/mailman/listinfo/gdal-dev
