The netCDF operators NCO version 3.9.5 are ready.
http://nco.sf.net (Homepage)
http://dust.ess.uci.edu/nco (Homepage "mirror")
This release extends the Multi-slabbing Algorithm (MSA) and -X switch
to operators beyond ncks: ncbo, ncea, ncecat, ncflint, ncpdq, ncra,
and ncrcat. Why might you care? MSA allows one to obtain and operate
on irregular hyperslabs. The fastest/simplest NCO-way to process data
from cell-based (e.g., geodesic) grids or flight-track trajectories,
for example, is to use MSA and/or -X to specify the hyperslabs.
This can be done two ways. First, multiple -d switches for the same
coordinate:
ncra -d lon,10.,15. -d lon,15.,20. -d lon,80.,90. in.nc out.nc
Note the multiple hyperslabs (multi-slabs) in the lon dimension.
ncks has always handled multi-slabs, now other operators do too.
Second, NCO now supports the -X argument to utilize CF-compliant
auxiliary coordinate variables. NCO searches the file for
variables with the "standard_name" attribute of "latitude" and
"longitude" and uses these coordinates. The argument to -X is a
box in the order lon_min,lon_max,lat_min,lat_max:
ncra -O -X 0.,180.,-30.,30. -v gds_3dvar in.nc out.nc
For more details, see
http://nco.sf.net/nco.html#msa
http://nco.sf.net/nco.html#aux
Karen Schuchardt of PNNL supplied the -X code and encouragement.
PNL will use -X to help analyze global cloud-resolving model data:
http://www.pnl.gov/science/highlights/highlight.asp?id=416
Henry Butowsky optimized the MSA implementation to support -X.
A. Multi-slabbing (MSA) available on most operators (Henry Butowsky)
ncbo, ncea, ncecat, ncflint, ncpdq, ncra, and ncrcat support MSA.
Auxiliary coordinates (Karen Schuchardt) available with -X.
http://nco.sf.net/nco.html#msa
http://nco.sf.net/nco.html#aux
B. ncap2 builds on Solaris (Henry Butowsky)
C. Prevent copying global metadata with -M, --metadata switch on
ncecat
http://nco.sf.net/nco.html#ncecat
D. Fix netCDF4-enabled NCO builds on cygwin. Thanks to Mark Hadfield.
E. Pre-built Debian Sid & Ubuntu Hardy packages are available.
http://nco.sf.net#debian
F. Pre-built RPM packages are available.
http://nco.sf.net#rpm
G. Did you try SWAMP (Script Workflow Analysis for MultiProcessing)?
SWAMP efficiently schedules and executes NCO scripts on remote servers:
http://swamp.googlecode.com
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 may speed things up.
Try SWAMP give us your feedback.
H. Reminder: NCO support for netCDF4 features is tracked at
http://nco.sf.net/nco.html#nco4
NCO currently supports netCDF4 atomic data types and compression.
NCO 3.9.5 with netCDF4 support should work with HDF5 1.8 final
and netCDF4 snapshot2008022009 and newer.
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
Enjoy,
Charlie
--
Charlie Zender, Department of Earth System Science, UC Irvine
Sab. at CNRS/LGGE-Grenoble until 20080815 :) 011+33+476+824236
Laboratoire de Glaciologie et Géophysique de l'Environnement
54 rue Molière BP 96, 38402 Saint Martin d'Hères Cedex, France
