Re: Degrib version 1.13

• To: "Arthur.Taylor" <Arthur.Taylor@xxxxxxxx>
• Subject: Re: Degrib version 1.13
• From: Robb Kambic <rkambic@xxxxxxxxxxxxxxxx>
• Date: Tue, 27 May 2003 10:47:07 -0600 (MDT)

Arthur,

Last week, I downloaded, installed, and ran some tests on your grib2 package.
Everything worked quite well, the code looks organized and there's
grib1 support in the code also.  There is support for multiple parameter
tables in the code and option flags to configure the output.  You did a good
job.

But, I do have one major concern, the package does not support streaming input.
Most of the grib decoders are inline decoders that get their input from the
NOAAPORT stream in some manner on STD input, AWIPS, Gempak, McIDAS,
gribtonc, etc. There's a couple reasons 1) the data is available in near-real
time in the desired format and 2) the data doesn't have to be stored twice,
once for each output format. Of course the 2nd reason isn't nearly as important
as the first but the future data streams will be in the order of gigabytes.

Do you plan on supporting streaming input?  After looking at the code, it
doesn't appear to be a major task.  It will take away your seeks to particular
points in the file but they could be replaced with offsets from a memory
pointer. I could have missed parts of your design so my guess on the amount
of work could be completely off base. But, I sincerely wish that you would
consider adding streaming input.  I'll attach a file called get_prod.c that
the gribtonc decoders uses to get grib products with the routine get_prod
using STD input.  I'm not saying that you should use the code, just look at
it for ideas, ok.

If you do add the streaming data input I would definitely use your
grib2 decoder with the Unidata LDM package. It would be enhanced to
have NetCDF file output also. Since your decoder supports GIS type
output formats, I could foresee it's use with many other packages in the
future.

Thanks again,
Robb...
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Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
rkambic@xxxxxxxxxxxxxxxx                   WWW: http://www.unidata.ucar.edu/
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