http://nco.sf.net (Homepage, Mailing lists, Help)
http://github.com/nco/nco (Source Code, Issues, Releases)
What's new?
Version 5.3.5 contains mostly speed, robustness, and documentation
improvements for the regridder. The ability to select alternate
executable and library paths for testing snapshots is also improved.
Skip this release if these changes do not interest you.
Enjoy,
Charlie
NEW FEATURES (full details always in ChangeLog):
A. The map checker (ncks --chk_map) is more robust and clear in its
reports. For robustness, the checker now ensures that all row/col
indices are valid before attempting to use them. Illegal values are
summarized and printed. The regridder also does now. Illegal values
previously caused the checker and regridder to die with baffling
core-dumps. Conservation and Consistency metrics now include
plain-language definitions.
B. The ncremap tutorial on the E3SM Confluence page
https://e3sm.atlassian.net/wiki/spaces/DOC/pages/edit-v2/754286611
now contains extensive documentation on how to exploit the three types
of parallelism (node-, workflow-, and thread-level) supported by
ncremap. New examples show the scaling of performance with OpenMP
threads for regridding and for weight-generation.
C. The --npo (NCO Path Override) option allows other users to
easily test bleeding-edge features present in development versions
of NCO in C. Zender's home directories at DOE HPC centers.
This feature has been updated to work with the latest paths on Andes,
Chrysalis, and Perlmutter.
http://nco.sf.net/nco.html#npo
http://nco.sf.net/nco.html#nco_path_override
D. All operators that accept -v as the option to indicate
a list of variables now also accept --var_lst. This makes
the binary executables consistent with ncremap/ncclimo.
http://nco.sf.net/nco.html#var_lst
E. plev can now be a full path name. Previously the pressure
levels for vertical interpolation were always contained in
the destination vertical grid file. However, pure pressure
vertical grids require only the plev variable so requiring
that variable to be in its own file was unnecessary. Now the 'plev'
variable can be specified as a full path name, e.g.,
--vrt=/home/bar/data.nc/plev. Here the variable "plev" will
be searched for in the file /home/bar/data.nc. This is similar to the
way the surface pressure ps for hybrid sigma-pressure coordinates can
be a full-pathname. This is the first step to supporting 3D pressure
fields as target grids.
ncremap --vrt=/path/to/file.nc/plev in.nc out.nc
http://nco.sf.net/nco.html#vrt
BUG FIXES:
A. GCC-compiled executables once again have working OpenMP parallelism
in the regridder. Previously only Clang or Intel-compiled executables
could access OpenMP parallelism in the regridder. GCC-compiled
installations always used one thread, no matter how many were
requested via --thr_nbr=# threads or OMP_NUM_THREADS. An incorrect CPP
token caused this misbehavior. Now both horizontal regridding and
vertical interpolation adhere to the requested parallelism. OpenMP
increases throughput by about a factor of two, so users of this update
may notice significant speed improvements. Safeguards and additional
checks have been implemented to prevent this problem from occuring
again. There is no workaround, users must upgrade to exploit OpenMP
while regridding with GCC-compiled installations.
http://nco.sf.net/nco.html#thr_nbr
http://nco.sf.net/nco.html#thr_nbr_ncremap
Full release statement at http://nco.sf.net/ANNOUNCE
--
Charlie Zender, Dept. of Earth System Science
University of California, Irvine 949-891-2429
