GrADS 2.0.a0

[Jennifer Adams]

At long last, GrADS 2.0.a0 is released!

Because NCEP will soon be distributing forecast data only in GRIB2
format, we are releasing an alpha version of GrADS 2.0. We are still
actively testing and debugging and documenting the code, but it is
working well for us internally at COLA, and we feel the time is right
for a public release.

GrADS 2.0 is a significant upgrade from 1.9 in many ways:
-- it has 'dtype grib2' and a new utility 'grib2scan'
-- it has a fifth dimension for gridded data sets
-- internal data handling is all double precision
-- undef handling is cleaner
-- the netcdf/hdf interface has been streamlined
-- the executable names are different:
        gradsc, gradsnc, and gradshdf are merged into 'grads'
        gradsdods is now 'gradsdap'

Because of these changes, and others that are still in the works but
haven't been implemented yet, there are some features which we can no
longer support. The UDF interface is disabled, but will be return
soon in a new implementation that should be easier to use. The lterp
() function (a widely used UDF) is now built-in. The LATS interface
is gone, but implementing a new path for writing out netcdf with
'gxout fwrite' is very high on our to-do list. Templating with the
'sdfopen' command is also no longer supported, and some special cases
of binary file formats are now a legacy: "var" and "z" transposed
data (units=-1,1) and "x" and "y" transposed data (units=-1,30). The
format of the GrADS metafile will also change, as graphics
improvements are implemented. The gv utility will not work with GrADS
2.0. Otherwise, for now, everything you do with GrADS should work in
version 2.

I have posted the source code and two binary tarballs in:
     ftp://iges.org/grads/2.0/
Binaries are for RedHatEnterpriseLinux5 (x86_64) and Intel Macs. If
you are using GrADS on a unix platform of a different flavor, I
highly recommend trying to build from source, since I will be posting
updates to the source code very frequently. A list of the required
supplemental libraries is in the documentation at http://iges.org/
grads/gadoc/supplibs.html . Almost all of these supplibs are upgrades
from previous versions and build easily. I will update this doc page
with additional guidance for building from source as soon as I can.

To get you started with NCEP GRIB2, I have also posted a couple of
sample descriptor files:
    http://iges.org/grads/gadoc/gfs.ctl
    http://iges.org/grads/gadoc/gfsens.ctl
The documentation on descriptor file elements ( http://iges.org/grads/
gadoc/descriptorfile.html )has been updated with information on the
EDEF entry and GRIB2 handling.

Please post comments and questions and bug reports here. As always, I
must be able to reproduce a problem on my own systems in order to fix
it, so keep that in mind when reporting bugs.

Jennifer

--
Jennifer M. Adams
IGES/COLA
4041 Powder Mill Road, Suite 302
Calverton, MD 20705
jma at cola.iges.org



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