netCDF Operators NCO version 5.1.8 make the scene
http://nco.sf.net (Homepage, Mailing lists, Help)
http://github.com/nco/nco (Source Code, Issues, Releases)
What's new?
Version 5.1.8 recognizes NC_STRING as valid alternatives to NC_CHAR
attributes (consistent with CF Conventions), infers MPAS grids stored
in radians when units attributes are not present, and support checks
for adherence to NASA DIWG (and CF) recommendations for valid
identiers, and for the missing_value attribute.
Skip this release if these issues are of no import to you.
Work on NCO 5.1.9 has commenced and aims to add support for Zarr S3
stores, and to polish support for new codecs..
Enjoy,
Charlie
NEW FEATURES (full details always in ChangeLog):
A. NCO operators are now much better, though not perfect,
at recognizing NC_STRING attributes as equivalent and interchangeable
with NC_CHAR attributes, as permitted by CF Conventions since ~2020.
In particular, this prevents annoying WARNINGs when CF attributes
like "bounds" are stored as NC_STRING. Thanks to Abel Aoun for
reporting/suggesting this.
B. ncremap can now infer SCRIP grid-files from MPAS datasets
when the coordinates are in radians yet not marked as such in
the units attribute. The algorithm simply assumes that if the
bounding latitudes and longitudes are within +/-2*pi then the
units are radians. Imperfect, yet unlikely to fail in most
MPAS meshes.
ncremap --dst_fl=AIS_4to20km.nc --grd_dst=ais4to20km_ismip6.nc
C. ncks supports a new flag, --chk_chr, that prints any identifiers
(dimension,group,variable,attribute names) that do not comply with
the CF Conventions. CF-compliant identifiers must match this
regular expression: [A-Za-z][A-Za-z0-9_]*
This is much more restrictive than the NUG, as it eliminates most
special characters.
$ ncks --chk_chr ~/nco/data/in.nc
...
ncks: WARNING nco_chk_chr() reports variable att_var_spc_chr attribute
name "at_in_name@" is not CF-compliant
ncks: WARNING nco_chk_chr() reports variable name "var_nm-dash" is not
CF-compliant
ncks: WARNING nco_chk_chr() reports variable var_nm-dash attribute name
"att_nm-dash" is not CF-compliant
ncks: INFO nco_chk_chr() reports total number of identifiers with CF
non-compliant names is 26
$
http://nco.sf.net/nco.htlm/chk_chr
D. ncks supports a new flag, --chk_mss, that reports which variables
(and groups) contain a missing_value attribute.
NASA's Dataset Interoperability Working Group (DIWG) notes that the
missing_value attribute has been semi-deprecated, and recommends that
it should not be used in new Earth Science data products.
To check a file for compliance with the DIWG recommendation:
$ ncks --chk_mss ~/nco/data/in.nc
ncks: WARNING nco_chk_mss() reports variable fll_val_mss_val contains
"missing_value" attribute
ncks: WARNING nco_chk_mss() reports variable
one_dmn_rec_var_missing_value contains "missing_value" attribute
...
ncks: WARNING nco_chk_mss() reports variable rec_var_int_mss_val_flt
contains "missing_value" attribute
ncks: INFO nco_chk_mss() reports total number of variables and/or groups
with "missing_value" attribute is 11
$
http://nco.sf.net/nco.htlm/chk_mss
E. ncremap and ncclimo now support paths and nodenames on DOE OLCF's
Frontier supercomputer.
BUG FIXES:
A. N/A
Full release statement at http://nco.sf.net/ANNOUNCE
--
Charlie Zender, Earth System Sci. & Computer Sci.
University of California, Irvine 949-891-2429 )'(
