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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Group, Please ignore my warning on 20141029 about unreadable files after chunking with NCO, nccopy, and h5repack. Although chunking can create unreadable files in some circumstances, the specific problems that I reported were false positives, i.e., I incorrectly diagnosed them. NCO, nccopy, and h5repack work well for the examples given (below). An unlikely coincidence of issues fooled my diagnosis with ncwa. I'll try to be more thorough/careful before responding about potential problems on this list. Apologies for any inconvenience this caused. czzender@roulee:~$ time ncks -O -4 --cnk_dmn latitude,4 --cnk_dmn longitude,4 --cnk_dmn time,512 ~/2014.nc ~/2014_ch_ncks.nc
real 2m27.044s user 0m39.915s sys 1m40.638szender@roulee:~$ time nccopy -c time/512,latitude/4,longitude/4 ~/2014.nc ~/2014_ch_nccopy.nc
real 2m27.931s user 0m39.730s sys 1m42.749s zender@roulee:~$ ncks -O -4 ~/2014.nc ~/2014.nc4zender@roulee:~$ time h5repack -l u10m:CHUNK=512x4x4 -i ~/2014.nc4 -o ~/2014_ch_h5repack.nc
real 0m2.907s user 0m0.479s sys 0m0.515s zender@roulee:~$ ncwa -O ~/2014_ch_ncks.nc ~/foo.nc zender@roulee:~$ ncwa -O ~/2014_ch_nccopy.nc ~/foo.nc zender@roulee:~$ ncwa -O ~/2014_ch_h5repack.nc ~/foo.nc zender@roulee:~$ -- Charlie Zender, Earth System Sci. & Computer Sci. University of California, Irvine 949-891-2429 )'(
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