Re: 20040226:valtime_offset problems gribtonc (fwd)

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

---------- Forwarded message ----------
Date: Mon, 1 Mar 2004 12:14:51 -0500 (EST)
From: Lori Thompson <address@hidden>
To: Robb Kambic <address@hidden>
Subject: Re: 20040226:valtime_offset problems gribtonc

Great, I'm getting 1 frame per netcdf file now. I guess that modification
is one that I did in combination with others.

Thanks for all your help,
Lori

On Mon, 1 Mar 2004, Robb Kambic wrote:

> Lori,
>
> I received the grib file and created a cdl file for your isabel data.
> The cdl from gribtocdl had to be modified a litte because it had
> valtime offsets of 0 and 6 because the PRECIP var is actually a time
> range and gribtocdl doesn't handle that well. ie
>
> >From gribdump:
>
>        Time Range Indicator : Accumulation from P1 to P2
>                 Time 1 (P1) : 0
>                 Time 2 (P2) : 6
>
> other vars were similar too:
>
>        Time Range Indicator : Reference Time + P1
>                 Time 1 (P1) : 6
>
> When gribtonc ran on the data, it only created one record for the 6 hr data.
> The cdl is a attached.
>
> Robb...
>
>
> On Thu, 26 Feb 2004, Robb Kambic wrote:
>
> > On Thu, 26 Feb 2004, Unidata Support wrote:
> >
> > >
> > > ------- Forwarded Message
> > >
> > > >To: address@hidden
> > > >From: Lori Thompson <address@hidden>
> > > >Subject: valtime_offset problems
> > > >Organization: UCAR/Unidata
> > > >Keywords: 200402261855.i1QItjrV024503
> > >
> > > We recently upgraded to the decoders version 3.0.2. I am converting a
> > > dataset from grib to NetCDF. During the conversion, each snapshot file was
> > > concatenated using nccatm to produce a time series file. I seem to be
> > > running into problems with this newer version where additional points are
> > > added to the record dimension during gribtonc, creating additional
> > > 9actually doubling) blank frames in the time series. I have made several
> > > attempts to manipulate the CDL file so that the record dimension will only
> > > have 1 value per file but these efforts failed. Is there a new feature
> > > with the upgrade that is causing this, or am I doing something wrong?
> >
> >
> > Lori,
> >
> > I am not quite sure that what your question is?
> >
> > The valtime_offsets are extracted from the data files. The
> > offsets must be in the raw grib data you used to make the cdl. You could
> > use use the gribdump utility to check your grib input file.  ie
> >
> > % gribdump <rawgrib> | less
> > ...
> >        Time Range Indicator : Reference Time + Long P1
> >                 Time 1 (P1) : 0
> >                 Time 2 (P2) : 12
> > ...
> >
> > This would result in a valtime_offset of 12.  You could edit the cdl file
> > in the data section.  Removing some of the values for the
> > valtime_offset, only used the offsets in the data that you are decoding.
> >
> > I don't know what the result would be if the variable valtime_offset was
> > removed from the data section. You would get some errors but not fatal
> > errors.
> >
> >
> > If none of the above ideas work, you might want to use the old version of
> > the decoder and modify the gribtocdl file section to look like lines
> > 1882-1937 in the latest gribtocdl.  I think that the actual changes might
> > be only a couple lines in that section. A simple recompile might solve
> > your problem.
> >
> > Let me know your findings. If you are still having problems, send me your
> > cdl an a sample grib file.
> >
> > Robb....
> >
> >
> > >
> > > Thanks,
> > > Lori
> > >
> > > --
> > > ----------------------------------------------------
> > > Lori A. Thompson
> > > Applications Programmer/RS Information Systems, Inc.
> > > Geophysical Fluid Dynamics Laboratory/NOAA
> > > Princeton University Forrestal Campus/Route 1
> > > PO Box 308
> > > Princeton, NJ 08542
> > > Phone: 609-452-6563
> > > Fax:   609-987-5063
> > > http://www.gfdl.noaa.gov/~lat
> > >
> > > --
> > > NOTE: All email exchanges with Unidata User Support are recorded in the
> > > Unidata inquiry tracking system and then made publically available
> > > through the web.  If you do not want to have your interactions made
> > > available in this way, you must let us know in each email you send to us.
> > >
> > > ------- End of Forwarded Message
> > >
> >
> > ===============================================================================
> > Robb Kambic                            Unidata Program Center
> > Software Engineer III                          Univ. Corp for Atmospheric 
> > Research
> > address@hidden                 WWW: http://www.unidata.ucar.edu/
> > ===============================================================================
> >
>
> ===============================================================================
> Robb Kambic                              Unidata Program Center
> Software Engineer III                    Univ. Corp for Atmospheric Research
> address@hidden                   WWW: http://www.unidata.ucar.edu/
> ===============================================================================

-- 
----------------------------------------------------
Lori A. Thompson
Applications Programmer/RS Information Systems, Inc.
Geophysical Fluid Dynamics Laboratory/NOAA
Princeton University Forrestal Campus/Route 1
PO Box 308
Princeton, NJ 08542
Phone: 609-452-6563
Fax:   609-987-5063
http://www.gfdl.noaa.gov/~lat