netCDF Operators NCO version 5.2.4 tip the spear
http://nco.sf.net (Homepage, Mailing lists, Help)
http://github.com/nco/nco (Source Code, Issues, Releases)
What's new?
Version 5.2.4 fully implements the CF lossy metadata convention
for three the three NCO internal quantization algorithms that
are also in libnetCDF. It also improves ncclimo diagnostics.
No major new features are implemented.
Skip this release if these changes are not important to you.
Work on NCO 5.2.5 has commenced and will add support for Zarr S3
stores, and will enhance the vertical regridder.
Enjoy,
Charlie
NEW FEATURES (full details always in ChangeLog):
A. All numeric operators now support --qnt as a synonym for --ppc.
Previous one could only use --quantize as a synonym, and --qnt
just seemed like it needed to be one too. The first three are the same:
ncks --ppc default=3 --ppc prs_sfc=5 in.nc out.nc # Granular Bitround
ncks --qnt default=3 --qnt prs_sfc=5 in.nc out.nc
ncks --quantize default=3 --quantize prs_sfc=5 in.nc out.nc
ncks --baa=8 --ppc default=12 --ppc prs_sfc=15 in.nc out.nc # Bitround
http://nco.sf.net/nco.html#qnt
http://nco.sf.net/nco.html#ppc
http://nco.sf.net/nco.html#quantize
B. All numeric operators now write CF-compliant metadata for quantization
algorithms through the NCO internal algorithms. (Previously NCO wrote CF
metadata only for quanitzation performed by the netCDF library.)
NCO no longer writes the really long quantization metadata attributes
such as QuantizeBitGroomNumberOfSignificantDigits. Note that libnetcdf
still does write these attributes (prepended by an underscore) when
its quantization functions are invoked.
% ncks -O -7 --baa=8 --qnt prs_sfc=6 --cmp='shf|zst' in.nc out.nc
% ncks -m -v prs_sfc,compression_info out.nc
netcdf foo2 {
dimensions:
lat = 2 ;
lon = 4 ;
time = UNLIMITED ; // (10 currently)
variables:
char compression_info ;
compression_info:family = "quantize" ;
compression_info:algorithm = "BitRound" ;
compression_info:implementation = "NCO version 5.2.4" ;
float prs_sfc(time,lat,lon) ;
prs_sfc:long_name = "Surface pressure" ;
prs_sfc:units = "pascal" ;
prs_sfc:lossy_compression = "compression_info" ;
prs_sfc:lossy_compression_nsb = 6 ;
} // group /
BUG FIXES:
A. None
Full release statement at http://nco.sf.net/ANNOUNCE
--
Charlie Zender, Dept. of Earth System Science
University of California, Irvine 949-891-2429
