Version 4.3.9 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:
We are pleased to report the birth of the operator nces.
nces is for netCDF Ensemble Statistics.
nces includes the existing functionality of ncea and extends it by
allowing groups to be treated as an unlimited dimension of datasets.
nces is really ncea with a powerful new feature and a new name.
I will debut nces at AGU (Friday 12/13 11:35 AM Moscone West 2010).
See below for more info on the feature. Regarding the name...
We renamed ncea as nces to more accurately describe the operator.
For historical reasons, NCO is full of misnamed operators:
NCO itself is misnamed because the operators now work well on HDF (4
and 5) files, not just netCDF files. We tried to change their name
to SDO (Scientific Data Operators) but the new name didn't stick.
And the "averagers" (ncea, ncra, ncwa) are all misnamed because they
all do many statistics (min/max/ttl/rms...) besides averages.
This feature addition is an opportune time to rename ncea as nces.
ncea is now deprecated, though will remain supported for some time.
We faced the same problem of back-compatibility when we renamed ncdiff
to ncbo many years ago. We will use the same method. Invoking 'nces'
produces the same results as the old 'ncea' so scripts do not break.
Under the hood, 'ncea' invokes 'nces --nsm_fl', just as 'ncdiff'
invokes 'ncbo --op_typ=subtract'. To cause nces to utilize the new
group ensemble mode, invoke it with 'nces --nsm_grp'. This is similar
to how ncecat has two modes, record aggregation (the default) and
group aggregation, invoked with 'ncecat --rag' and 'ncecat --gag',
respectively.
This version also improves ncks support for XML (NcML) output.
All output now validates without errors with the NcML 2.2 schema.
Happy NcML'ing! There is also a bugfix for NaNs in ncatted.
Additional details are available in the ChangeLog.
