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Re: 20040625: GRIB problem in decoders-3.0.2 - bug?



On Mon, 28 Jun 2004, Arild Burud wrote:

> Robb Kambic wrote:
> > Thanks again for the gribtocdl code. I wonder if version 3.0.0 had the
> > same problem as 3.0.2?
>
> Well, I didn't have the problem in the first version of
> gribtocdl/gribtonc. Haven't tested the intermediate versions, but it
> sort of made sense to see that valtime_offset was introduced together
> with this problem.
>
> > At first thought, I don't see how the
> > forecasttime variable could cause this problem but maybe there is a
> > dependancy that I over looked. I'll check it out.
>
Arild,

The dependancy that I over looked was the calculation of the variable
valtime_offset was delayed until gribtonc was invoked in the previous
version of gribtocdl. My calculation of valtime_offset in gribtocdl needed
to invoke the routine frcst_time() to obtain the correct value.

gribtocdl now creates the correct cdl for the sample data set you sent and
the results of gribtonc now only has one record.

> As I said, changing the "Time 2 (P2) : 24" into "Time 2 (P2) : 0" in the
> grib data completely removed the problem. At least I view it as a
> problem when a "monthly mean" dataset becomes two datasets 24 hours
> apart....
> As "Time 2 (P2)" is mostly used as "Time interval between successive
> analysis" it seemed logical that it could also be retreived as
> "valtime_offset".
>
> Anyway there is no hurry to fix this, but I just wanted to inform you of
> my findings.
>
>
Thanks for the bug report, I put a version of gribtocdl.c in the ftp dir
if you want to try it out.  There will probably be a decoders release in a
couple of weeks.

Robb...


> Arild
> --
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>

===============================================================================
Robb Kambic                                Unidata Program Center
Software Engineer III                      Univ. Corp for Atmospheric Research
address@hidden             WWW: http://www.unidata.ucar.edu/
===============================================================================