Version 4.7.0 of the netCDF Operators (NCO) has been released. NCO is an Open Source package that consists of a dozen standalone, command-line programs that take netCDF files as input, then operate (e.g., derive new data, average, print, hyperslab, manipulate metadata) and output the results to screen or files in text, binary, or netCDF formats.
The NCO project is coordinated by Professor Charlie Zender of the Department of Earth System Science, University of California, Irvine. More information about the project, along with binary and source downloads, are available on the SourceForge project page .
From the release message:
Version 4.7.0 adds spit and polish throughout the toolkit. Nothing major stands
out, except perhaps for easy access to compression algorithms in
fl_fmtoptions for output file format. The option behaves the same as it does for other operators:
ncclimo [-3 -4 -5 -6 -7] ... ncremap [-3 -4 -5 -6 -7] ... ncclimo --fl_fmt=netcdf4 ... ncremap --fl_fmt=cdf5 ...http://nco.sf.net/nco.html#fl_fmt
dfl_lvloption for compression. The value of
dfl_lvlis an integer fro 0..9 that specifies the DEFLATE (= Lempel-Ziv + Huffman) compression level for netCDF4. The option behaves the same as it does for other operators:
ncclimo --dfl_lvl=3 ... ncremap --dfl_lvl=3 ... ncclimo -L 3 ... ncremap -L 3 ...http://nco.sf.net/nco.html#deflate
ppcoption for Precision-Preserving Compression. Other operators allow multiple, per-variable PPC specification.
ncclimoallows only one PPC option, equivalent to specifying
--ppc default=<val>with the compiled operators. NB: regridding does not yet accept PPC.
ncclimo --ppc=3 ...http://nco.sf.net/nco.html#ppc
ncrenameis now quiet by default, like all other operators. The old summary line that tallied the numbers of things renamed can still be seen by invoking
CMake: Pedro Vicente contributed a CMake build-engine in 4.6.9. The CMake engine
now correctly links ncap2 to intrinsic math functions like
gamma(), ... Please give us feedback on any wrinkles in the CMake build. To build with CMake and install in
cd nco/cmake cmake .. -DCMAKE_INSTALL_PREFIX=/usr/local make sudo make installAdditional examples in
The automatic CDF5 bug checker in 4.6.9 has been turned-off. It produced too much
distracting output in workflows affected by the CDF5 bug. To activate this
check, build NCO with, e.g.,
CPPFLAGS='-DNCO_CDF5_BUG_CHK' ./configure ...The checker itself has been improved so that, when turned on, operators are now quiet when sniffing CDF5 files for corruption, until they detect a "large" (> 4 GB) variable. In 4.6.9 the sniffing algorithm was noisier, and printed an INFO upon closing any CDF5 file.
Additional details are available in the ChangeLog.