The Unidata Program Center (UPC) is pleased to announce the initial
release of a software package for manipulating netCDF data sets in
UNIX-like environments. This package consists of three netCDF operators,
an associated support library, and documentation.
A netCDF operator is an executable program that reads one or more input
netCDF data sets, generating one or more output netCDF data sets. The
netCDF operators are intended to:
* Support the sharing of data by acting as front- and back-end
filters to other, more comprehensive data analysis packages;
* Perform quick and dirty data analysis and manipulation; and
* Provide examples of generic netCDF programs.
The netCDF operators in this initial release constitute the "proof of
concept" operator set. They are:
ncstat Generates statistics of netCDF variables over specified
dimensions.
ncextr Extracts the specified (or everything but the
specified) variables and attributes from a netCDF data
set.
ncbarne Performs a fast Barnes objective analysis on a netCDF
data set in Euclidean space. (Sorry, geographical
space isn't supported, yet.)
The `ncstat' and `ncextr' operators are written in C. The `ncbarne'
program is written in FORTRAN as an example in that language.
One feature of the netCDF operators is that they can read an input
netCDF data set from standard input and can also write an output netCDF
data set to standard output. Thus, the operators can be used in UNIX
pipelines (although this is only recommended for small data sets).
Other netCDF operators will become available as they are completed and
will be announced via the netCDF mailing-list. (Indeed, one such operator,
nccut, which extracts a subdomain of a netCDF data set, should be released
very soon.) To subscribe to the netCDF mailing-list, email a request to
netcdfgroup-request@xxxxxxxxxxxxxxxx
This netCDF operator package is freely available and can be obtained
via anonymous FTP from the UPC in the usual way:
host: unidata.ucar.edu [128.117.140.3]
file: pub/sdm/ncopers.tar.Z
One note of caution: before attempting to build this operator package,
you should have the latest versions of the following packages installed on
your system:
Unidata
Package Description & Comments Available as File
------- ---------------------- -----------------
netCDF Unidata netCDF package. pub/netCDF.tar.Z
gmake GNU make(1) program. pub/gmake-<cpu>.Z
<cpu> depends on the
workstation type:
Workstation <cpu>
----------- -----
DECstation ds
IBM RS6000 rs6000
SGI sgi
SPARCstation sparc
This is the actual
executable program: not
source code. Don't
forget to do a `chmod +x'
on it after uncompressing.
Makefile Unidata make(1) package. Should pub/sdm/Makefile.tar.Z
be unpacked in the parent directory
of the one containing the operator
package. Put another way, the
Unidata software packages should be
in child directories of a Unidata
source directory (e.g.
/usr/local/unidata/src).
udposix Unidata portability package. pub/sdm/udposix.tar.Z
udape Unidata miscellaneous function pub/sdm/udape.tar.Z
library.
You may obtain any of the above via anonymous FTP from the same host.
This netCDF operator software package is a peer of other Unidata
software packages and should be unpacked and built as such. The following
procedure is suggested:
1. Obtain this package (and any other packages you might need or
want), placing it (or them) in your Unidata source directory
(e.g., /usr/local/unidata/src):
% cd /usr/local/unidata/src
% ftp unidata.ucar.edu
Connected to groucho.
220 groucho FTP server (SunOS 4.1) ready.
Name (unidata.ucar.edu:steve): anonymous
Password:
230 Guest login ok, access restrictions apply.
ftp> binary
200 Type set to I.
ftp> cd pub/sdm
250 CWD command successful.
ftp> get ncopers.tar.Z
200 PORT command successful.
150 Binary data connection for ncopers.tar.Z
(128.117.140.3,3034) (391487 bytes).
226 Binary Transfer complete.
local: ncopers.tar.Z remote: ncopers.tar.Z
391487 bytes received in 0.69 seconds (5.5e+02 Kbytes/s)
...
ftp> bye
%
2. Unpack this package (and any others) in the same Unidata source
directory:
% zcat ncopers.tar.Z | tar -xf -
%
This will create the subdirectory `ncopers/' and unpack the
netCDF operator package into it.
3. If you haven't installed the latest versions of the above-
mentioned, prerequisite packages, then you can build and install
them and this package (and every other Unidata package you
have!) in one step:
% gmake udposix/all udposix/install \
udape/all udape/install \
ncopers/all ncopers/install >& log &
% tail -f log
Otherwise, if you only want to build and install certain
packages -- such as this package and the prerequisite packages
-- then use something like the following:
% gmake udposix/all udposix/install \
udape/all udape/install \
ncopers/all ncopers/install >& log &
% tail -f log
NOTES:
a. The above commands log the installation process and let
you view it at the same time. If case of difficulty,
any request to the UPC for assistance should include the
log file.
b. `gmake' in the above represents the name you have given
to the GNU make(1) utility.
You should know that this initial package has only been tested on the three
UPC-supported platforms: IBM's RS6000 running AIX, SUN's Sparc running
SunOS, and DEC's DECstation running ULTRIX. Therefore, although
considerable effort has gone into making this package portable, it is
possible (indeed likely) that this package cannot be built on some
unsupported platforms without manual intervention. The UPC is interested
in hearing about such porting issues and problems and may advise such
efforts.
As always, comments directed to the UPC on this package should be sent
to
support@xxxxxxxxxxxxxxxx.
If you feel that your comments have general interest, however, then you may
send them to the netCDF mailing-list.
