1999/08/31:
A bug involving ncwa, weights, and missing values has been
identified and fixed.
When ncwa was used to average variables with user-specified
weights (i.e.,
1999/08/29: NCO now builds completely with pure C source files by default. In the past, NCO used Fortran routines to perform floating point arithmetic and pure C builds could be manually enabled by specifying -DC_ONLY in the build environment. The interface between Fortran and C, however, was very difficult to maintain on the wide variety of platforms supported by NCO. Now pure C builds are the default and Fortran arithmetic must be manually enabled by specifying -DUSE_FORTRAN_ARITHMETIC in the build environment. See the User's Guide for details. The Fortran code is no longer supported and will probably be deprecated in future releases.
1999/08/05: NCAR users will be pleased to know that NCO now takes advantage of the local msrcp command, if it exists in a standard location on the local network. This allows all operators to retrieve files from the NCAR mass storage unit when msrcp is available on the local system. This change is transparent to the user, so that commands should still specify the paths to the files on the mass store with, e.g., ncks -O -R -l ./ /ZENDER/nc/in.nc foo.nc. See the User's Guide for more details.
1999/07/03:
ncatted now replaces missing values of variables whose
1999/05/09: ncks now alphabetizes output by default. To turn off alphabetization and return to the previous behavior (variables reported in the order they were written to disk) simply specify `-a' on the command line. Yes, that means the behavior of `-a' has been toggled.
ncrcat and ncra now support a
ncrcat and ncra now support index-based
hyperslabbing in the record dimension across files, e.g.,
ncra -d time,1,100 in1.nc in2.nc ... out.nc
The User's Guide claimed this feature had already been implemented,
but, due to an oversight, that was not true.
Attempting to use this new feature in older versions of NCO resulted
in an "index out of range" error.
Thanks to John Truesdale 1999/04/20:
Fixed bug where ncrcat and ncra omitted the last slice of the
record dimension when `-F' (Fortran indexing) was user-specified AND
user-specified hyperslab information was provided for some
dimensions BUT not for the record dimension. This bug only
affected ncrcat and ncra and only under these conditions. Thanks
to John Sheldon 1999/04/04: By default, extracted variables appear in the same order
in which they were written to the source netCDF file.
However, this order is often essentially random, making it hard to
locate a particular variable in a dump of many variables.
To help address this, ncks will now alphabetize variables.
Simply specify `-a' on the command line.
1999/01/21: An optional token has been added to NCO which eliminates
all netCDF 3.x calls and thus restores compatibility of NCO with HDF
files.
1998/12/02: ncwa has been updated again since a user
discovered a bug which occurred when a weight (`-w') and a
mask (`-m') were both given to ncwa. Unfortunately,
ncwa sometimes produced incorrect answers in this scenario so
if you ever used weights and masks at the same time you are strongly
urged to upgrade your NCO and rerun the commands. This bug only
affected variables averaged with both the weight and mask options
enabled at the same time, no other variables would have been affected.
The `-n' and `-W' normalization options to
ncwa have been removed, possibly permanently, but at least
until their implementation is simplified and redesigned. The
`-N' option to ncwa remains the same. All the new
behavior is fully documented in the rewritten and expanded
ncwa section in the
NCO User's
Guide.
1998/11/24: Choose whether to weight your coordinates in ncwa
A `-I' switch has been added to ncwa.
Henforth, by default, ncwa applies weights or masks to
coordinate variables just like any other variable.
Previously, ncwa did not weight coordinate variables at all,
and always produced simple arithmetic averages of coordinate
variables.
Use `ncwa -I' to recover the old behavior (i.e., arithmetic
rather than masked, weighted averages of coordinate variables).
A problem where ncwa would refuse to average variables which
did not contain any of the averaged dimensions has also been fixed.
1998/07/07: Reduce bloating!
The `-h' switch has been enabled on all operators.
Using this switch suppresses the automatic history feature in NCO.
Now you can decide whether each change to a file warrants an
additional line in the history attribute.
The functionality of the old `ncks -h' switch is now
invoked with `ncks -m' (the mnemonic is `metadata').