From: Charlie Zender <zender@uc...> - 2010-09-03 03:27:08
The netCDF operators NCO version 4.0.3 are ready.
http://dust.ess.uci.edu/nco (Homepage "mirror")
This version contains only bug-fixes and improvements.
Two of these bugs were recently introduced and could cause core dumps
in relatively common situations, so it was important to generate a new
stable release before the next Debian and Ubuntu distributions froze.
Short explanations of these bugs appear below.
Work on NCO 4.0.4 is underway. Areas of improvement include
Support for spectral transforms, chunking in all operators,
more chunking rulesets.
"New stuff" in 4.0.3 details:
A. Correctly write averaged date with ncra on CCM/CCSM/CF files
Fixes bug introduced in 4.0.1 that can segfault on ncra averages
B. Fix bug exposed by xlC compilers that caused ncbo segfaults on AIX
This bug was present in ncbo versions 4.0.0-4.0.2
C. Sense, handle MAC OS X on x86_64 chips
Thanks to drkdev for solving this problem
D. Configure works better with ncap2, netCDF4, UDUnits2, and netCDF-DAP
Thanks to Eric Blake of RedHat for simplifying M4 definitions
J. ncks and ncecat support netCDF4 chunking options:
These options can improve performance on large datasets.
Large file users: Send us suggestions on useful chunking patterns!
More useful chunking patterns may be implemented in NCO 4.0.3.
ncks -O -4 --cnk_plc=all in.nc out.nc
K. Pre-built, up-to-date Debian Sid & Ubuntu Karmic packages:
L. Pre-built Fedora and CentOS RPMs:
M. Did you try SWAMP (Script Workflow Analysis for MultiProcessing)?
SWAMP efficiently schedules/executes NCO scripts on remote servers:
SWAMP can work command-line operator analysis scripts besides NCO.
If you must transfer lots of data from a server to your client
before you analyze it, then SWAMP will likely speed things up.
N. NCO support for netCDF4 features is tracked at
NCO supports netCDF4 atomic data types, compression, and chunking.
NCO 4.0.3 with was built and tested with HDF5 hdf5-1.8.4 and with
NCO may not build with earlier, and should build with later, netCDF4
This is particularly true since NCO 4.0.3 takes advantage of an
internal change to the netCDF nc_def_var_chunking() API in June 2009.
export NETCDF4_ROOT=/usr/local/netcdf4 # Set netCDF4 location
cd ~/nco;./configure --enable-netcdf4 # Configure mechanism -or-
cd ~/nco/bld;./make NETCDF4=Y allinone # Old Makefile mechanism
O. Have you seen the NCO logo candidates by Tony Freeman, Rich
Signell, Rob Hetland, and Andrea Cimatoribus?
Tell us what you think...
GSL functions added to ncap2 in 4.0.3:
(Most desired GSL functions have been merged)
Charlie Zender, Department of Earth System Science
University of California, Irvine (949) 891-2429 :)