The netCDF Operators NCO version 5.0.3 are on tap.
http://nco.sf.net (Homepage, Mailing lists, Help)
http://github.com/nco (Source Code, Issues, Releases, Developers)
What's new?
Version 5.0.3 contains significant improvements to the quantization
algorithms and fixes to MOAB/mbtempest regridding. NCO now supports
the Digit Round and Granular BitGroom quantization algorithms. The
failed self-test problems that prevented Conda from building NCO
5.0.2 have been fixed, and a 5.0.3 Conda package will soon be
available.
Work on NCO 5.0.4 has commenced and will improve ncremap support
for MOAB, incorporate new MOAB improvements, and further improve
quantization metadata and algorithms.
Enjoy,
Charlie
NEW FEATURES (full details always in ChangeLog):
A. Lossy quantization algorithms have been refactored. First, the
attribute name that store the level of quantization are now
algorithm-specific, e.g.,
QuantizeBitGroomNumberOfSignificantDigits. Previsously, NCO
stored the NSD attribute number_of_significant_digits. However,
this was deemed too ambiguous, given the increasing number of
supported quantization methods. The new attribute names better
disambiguate which algorithm was used to quantize the variable.
Second, the default algorithm has been changed from BitGroom with
BitRound masks from R. Kouznetsov (2021), to what we call Granular
BitGroom (GBG). GBG combines features of BitGroom,
BitRound, and DigitRound by Delaunay et al. (2019). GBG improves
compression ratios by ~20% relative to BitGroom for NSD=3 on
our benchmark 1 GB climate model output dataset.
ncks -7 -L 1 --ppc default=3 in.nc out.nc # GranularBitGroom
ncks -7 -L 1 --baa=0 --ppc default=3 in.nc out.nc # BitGroom
ncks -7 -L 1 --baa=1 --ppc default=3 in.nc out.nc # BitShave
ncks -7 -L 1 --baa=2 --ppc default=3 in.nc out.nc # BitSet
ncks -7 -L 1 --baa=3 --ppc default=3 in.nc out.nc # DigitRound
ncks -7 -L 1 --baa=4 --ppc default=3 in.nc out.nc # GranularBitGroom
ncks -7 -L 1 --baa=5 --ppc default=3 in.nc out.nc # BitRound
ncks -7 -L 1 --baa=6 --ppc default=3 in.nc out.nc # HalfShave
ncks -7 -L 1 --baa=7 --ppc default=3 in.nc out.nc # BruteForce
Documentation on Bit-Adjustment-Algorithms (BAA) 3-7 will be
improved in the future. Bit-Groom/Shave/Set are described here:
http://nco.sf.net/nco.html#ppq
http://nco.sf.net/nco.html#gbg
BUG FIXES:
A. ncremap fixes issues that caused a self-test to fail.
This prevented Conda from building an NCO 5.0.2 package.
The tested algorithm is now 'fv2fv_flx' not 'tempest'. The
MPI-enabled E3SM-Unified (SYSTEM) environment no longer changes
the behavior of ncremap commands. --mpi_nbr now has complete
control over whether mpirun (or srun) commands are issued.
Full release statement at http://nco.sf.net/ANNOUNCE
--
Charlie Zender, Earth System Sci. & Computer Sci.
University of California, Irvine 949-891-2429 )'(
