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19990701: next GEMPAK question

John,

All of the GEMPAK GD programs utilize a Gempak gridded data file
such as is created by nagrib or dcgrib for model data, or one
that had objectively analyzed observations such as would be
output from oabsfc or oabsnd for surface and upperair data
respectively. The file name extension is not important
in identifying the file type contents.

Unidata provides a "decoders" package:
ftp://ftp.unidata.ucar.edu/pub/decoders/decoders.tar.Z

The program gribtonc (grib to netcdf) is commonly used by Unidata sites
to decode GRIB data into a NetCDF format file. This program is akin
to dcgrib in that is decodes grib data into a specific output file type.
You can find documentation on the decoders package as well as NetCDF on
our WWW page.

Steve Chiswell
Unidata User Support




On Fri, 2 Jul 1999, John Knox wrote:

> Dear Steve,
> 
> Thanks for the message.
> Quick follow-ups:
> 
> 1) gdlist requires a .grd file; how is that file created?
> 
> and
> 
> 2) what are the steps toward creating a NetCDF version of 
> the raw grid data?  Can I find this in documentation 
> somewhere instead of bugging you?
> 
> Thanks, and have a great holiday weekend,
> 
> John
> 
> On Thu, 1 Jul 1999 17:38:31 -0600 Steve Chiswell 
> <address@hidden> wrote:
> 
> > John,
> > 
> > It depends on the type on input needed by your 3D package
> > as to what you would output.
> > 
> > You can use gdlist to output data to an ascii file with
> > OUTPUT=f/filename. You could also write a program to read the gempak data
> > file using routines provided in the gempak library and write it into
> > whatever format your needed. Also, there are some programs called gemvis
> > (not part of gempak) that can convert the gempak data into Vis-5D format.
> > Otherwise, if you have the raw grid bata, you can convert it into NetCDF
> > format and many packages like IDL, NCARGraphics, matlab etc can read
> > NetCDF files.
> > 
> > In general, you can always send questions to address@hidden.
> > If I'm on vacation or out of the office, someone else may get to your
> > question quicker than myself. Also, there is the gembud mail list where
> > you might be able to get information on how other Unidata sites are
> > solving the problem.
> > 
> > Steve Chiswell
> > Unidata User Support
> > address@hidden
> > 
> > 
> > 
> > On Thu, 1 Jul 1999, John Knox wrote:
> > 
> > > Steve,
> > > 
> > > Thanks for all your help with GEMPAK.
> > > Now, a new question: let's say we want to do some 3D 
> > > visualization of the data.  If we want to put a subset of 
> > > the data into a file for use with another software package, 
> > > how is that done [if it's doable]?  
> > > 
> > > Also: should I be bugging you with these questions?  I feel 
> > > like our needs are at a pretty basic level, but I've not 
> > > been successful at answering them via the Web so far.
> > > 
> > > Thanks,
> > > 
> > > John
> > > 
> > > 
> > > 
> > 
> 
> ------------------------------------------------
> Dr. John A. Knox
> Assistant Professor of Geography and Meteorology
> Room 15, Mueller Hall
> Valparaiso University
> Valparaiso, IN 46383
> E-mail: address@hidden
> Office Phone: 219-464-6003
> 
>