NOAA / NWS's Meteorological Development Laboratory
Degrib (NDFD GRIB2 Decoder)
Subject: Degrib version 1.13
Date: Wed, 14 May 2003 13:55:53 -0400
Organization: DOC/NOAA/NWS - National Weather Service
To: Arthur Taylor
Sorry about this... I know 1.12 came out on Monday, but I was informed
today by Ira Graffman and Heather from ESRI that my polygons are inside
out. So, without further ado here is 1.13..
You all have the unique distinction of being registered on my degrib
(aka NDFD_GRIB2Decoder) mailing list (all 56 of us) (I'd like to
welcome: karin.larsson, ferrell, and Doug Wilson)
Please let me know (email me) if you want to unregister.
I just wanted to let you all know that I have just finished putting
together version "1.13" (last one that I announced was "1.12" on
The newest version of the program is on:
New to release 1.13:
1) Hopefully fixed the polygon option for the last time... I was
creating polygons that were going counter-clockwise around the cell,
instead of the way ESRI specified, which is clockwise. Using the union
option in ArcView, one can combine all the polygons of a particular
value together, thus reducing the size, speeding the draws and making it
useable in ArcIMS. The trick is that the union option needed clockwise
polygons. Attempting to union the NDFD grid with counter-clockwise
polygons takes 30 to 60 minutes, and the results are humorous at best,
useless at worst. Using clockwise polygons it took a max of 3-4
minutes, and had much better results.
2) Improved the "IsGrib2" function for the GUI. It had been looking at
every byte in a file before determining if a file was or was not a GRIB
(1 or 2) file. This was slow (particularly if you had large files in
that directory). It now only looks at the first 300 bytes. If it
doesn't find "GRIB" in those 300 bytes it states that it is not a GRIB
file, which is used for the choice of icon in the GUI display. The GUI
does allow one to treat a file, that it had determined was not a GRIB
file, as a GRIB file, just in case the first GRIB message was further in
than 300 bytes.
3) Created an icon for GRIB1 files which is different than the one for
4) Tweaked the GUI some to handle GRIB files with 1000+ messages (see
MOS GRIB 1)
5) Minor bug fix in FindSectLen that doesn't really affect anything.
As always, I tested this release on my PC (win 2000), a Linux machine, a
HP-Unix machine, and an AIX-Unix (machine). Although I may have missed
something in my testing, it should at least compile, and run for some of
the test cases. For those of you with access to the NWS NCEP machine,
my current version is in: /nfsuser/g06/we25at/degrib (on snow/frost, I'm
no longer using asp/bsp). For those with access to
MDL's GDP or NHDW machines, see: ~taylor/degrib/
Please let me know if you have problems.
(and again, I apologize for the frequency of these emails).