[netcdfgroup] netCDF Operators NCO version 4.7.3 have hatched

• To: NCO Announce Mail List <nco-announce@xxxxxxxxxxxxxxxxxxxxx>, netCDF Mail List <netcdfgroup@xxxxxxxxxxxxxxxx>
• Subject: [netcdfgroup] netCDF Operators NCO version 4.7.3 have hatched
• From: Charlie Zender <zender@xxxxxxx>
• Date: Fri, 2 Mar 2018 13:55:10 -0800

The netCDF Operators NCO version 4.7.3 have hatched.

http://nco.sf.net (Homepage, Mailing lists, Help)
http://github.com/nco (Source Code, Issues, Releases, Developers)

What's new?
Version 4.7.3 contains little features and fixes.
A new security whitelist could break some workflows, and the
other features offer better support for TempestRemap, MPAS, and
heavy users of NCO print features in CDL, JSON, and XML.

Work on NCO 4.7.4 has commenced. Planned changes include
better diagnosis and workarounds for the netCDF CDF5 bug,
parallel weight generation by ncremap, and possibly workarounds for
using quotation marks with ncap2 in Windows.

Enjoy,
Charlie

NEW FEATURES (full details always in ChangeLog):

A. Filename character whitelist:
   NCO manipulates files, sometimes with shell calls.
   We have never received a report of a security issue due to NCO.
   Nevertheless, to pre-emptively reduce potential vulnerabilities, we
   instituted in 4.7.3 a whitelist of allowed filename characters:
   abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ1234567890_-.@ :%\/
   The implied blacklist includes ;|<>[](),*
   If you want a character(s) added to the whitelist, please send us
   the rationale and a real-world use-case.
   http://nco.sf.net/nco.html#whitelist

B. ncremap implements E3SM-recommended Tempest remapping algorithms.
   It has done so since 4.7.2, but that version omitted a switch that
   only a user can provide, and is necessary to indicate to
   TempestRemap to generate mapping weights from a source grid that
   has more coverage than the destination grid, i.e., the destination
   grid is a subset of the source. The switch is --a2o, or --atm2ocn,
   or numerous synonyms (b2l, big2ltl, l2s, lrg2sml).
   When computing the intersection of two meshes, TempestRemap uses an
   algorithm (an executable named GenerateOverlapMesh) that expects
   the mesh with less coverage to be the first grid, and the grid with
   greater coverage to be the second, regardless of mapping direction.
   By default, ncremap supplies the source grid first and the
   destination second, and this order causes GenerateOverlapMesh to
   fail when the source grid covers regions not in the destination
   grid. For example, a global atmosphere grid has more coverage than
   a global ocean grid, so that remapping from atmosphere-to-ocean
   would require invoking the --atm2ocn switch:
   ncremap --a2o -a se2fv_flx --src_grd=ne30.g --dst_grd=fv.nc -m map.nc
   http://nco.sf.net/nco.html#a2o
   http://nco.sf.net/nco.html#ncremap

C. ncclimo supports two more dataset filename template regular
   expressions: prefix.YYYY-MM.suffix, and prefix.YYYY-MM-01.suffix.
   When such a name is the argument to --caseid, the prefix and suffix
   will be automatically abstracted and used to template and generate
   all monthly filenames based on the specified yr_srt and yr_end.
   Please tell us any dataset filename regular expressions that you
   would like added to ncclimo rx database.
   ncclimo -s 300 -e 400 --caseid=foo.0300-01-01.nc -i . -o /tmp
   http://nco.sf.net/nco.html#caseid

D. printf() format option for printed output (CDL, XML, JSON, TRD).
   Formerly ncks would always print variable values with the default
   format specification for the given output type. This meant that,
   single and double-precision values would print ~7 and ~15 digits,
   respectively. The new --fmt_val option causes ncks to use the
   supplied printf() format string to print floating point values:
   ncks --fmt_val %.5f ~/nco/data/in.nc
   will print up to five significant digits, and no more.
   This allows users to round numbers before printing them.
   http://nco.sf.net/nco.html#fmt_val

E. ncks now accepts a --print_file=file option to print directly to
   the named file rather than to stdout. Previously one could
   achieve the same result by redirecting stdout to a named file.
   However, it is slightly faster to print formatted output directly
   to a file than to stdout.
   ncks --print_file=foo.txt --jsn in.nc
   Synonyms are --fl_prn, --prn_fl, --file_print, and --print_file.
   http://nco.sf.net/nco.html#prn_fl

F. ncap, the predecessor to ncap2, has been completely eliminated.
   This simplifies the build procedure by eliminating Bison/Yacc.
   (Flex/Lex is still needed for other operators (notably ncwa)).
   Old files may cause local NCO repositories to fail to build.
   If this occurs, simply delete then re-check-out the repository.

BUG FIXES:

A. Those who build NCO from source will notice that most or all of
   the compiler warnings from building ncap2 have been eliminated.

Full release statement at http://nco.sf.net/ANNOUNCE

Enjoy!
Charlie
--
Charlie Zender, Earth System Sci. & Computer Sci.
University of California, Irvine 949-891-2429 )'(