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Re: 20031003: gribtocdl not writing data

On Fri, 3 Oct 2003, Lori Thompson wrote:

> So the cdl file only contains information on the coordinates and not
> the data for the variables?

Lori,

That's correct, cdl are only template files for the netCDF files.


I have done ascii to NetCDF conversions
> where the cdl file takes the form:
>
> data:
> lev = ;
> lon = ;
> lat = ;
> var1 = ;
> var2 = ;
> .
> .
> .
> varn = ;
> }
>
> So are you saying that gribtocdl will create a cdl file with only:
> data:
> lev = ;
> lon = ;
> lat = ;
> }
>
> I used gribtonc following gribtocdl and received the error message:
> ncgen: isabel13l.2003091100.grib3rd.f00.cdl line 258: too many values for
> this variable, 225 >= 225
>
> This is referring to the lon points which have 226. The same is true for
> lat. I manually removed the extra lon/lat points and reran gribtonc and
> received a segmentation fault. I did this for 225 and 224 point.
>

I hate to say this but gribtocdl isn't perfect becasue there are so many
variations of GRIB files, it's used as a starting point as you found out.
Deleting the extra lat/lon points etc was the correct thing to do.

If you send me the cdl file and a grib product, I'll take a look at it.
Also what version of the decoders package are you using?  One version did
do segmentation fault on some GRIB products but I thought it was fixed.
This could be a good test case for me.

Robb...


>
> Thanks,
> Lori
>
>
> I did have a misunderstanding of gribtocdl. I thought the cdl
> file was supposed to contain
>
> On Fri, 3 Oct 2003, Robb Kambic wrote:
>
> > On Fri, 3 Oct 2003, Unidata Support wrote:
> >
> > >
> > > ------- Forwarded Message
> > >
> > > >To: address@hidden
> > > >From: Lori Thompson <address@hidden>
> > > >Subject: gribtocdl not writing data
> > > >Organization: NOAA
> > > >Keywords: 200310031240.h93CeHk1011045 gribtonc gribtocdl
> > >
> > > Hello. I'm using gribtocdl and gribtonc to convert grib files to NetCDF.
> > > The grib data files have 7 variables, 5 of which have a vertical
> > > structure. gribtocdl creates the cdl file and returns the message:
> > >
> > > Oct 03 12:38:02 gribtocdl[10036]: Starting Up
> > > Oct 03 12:38:04 gribtocdl[10036]: EOF on input
> > > Oct 03 12:38:04 gribtocdl[10036]: Exiting
> > > Oct 03 12:38:04 gribtocdl[10036]: 111 WMO msgs, 111 GRIBs decoded, 111
> > > written
> > >
> > > which contains the correct number 111. The cdl file writes out the lat/lon
> > > and time data correctly and has the correct metadata for the variables.
> > > However, the cdl file does not write out any data for the variables and
> > > ends with lat data.
> >
> > Lori,
> >
> > I think you have a slight misunderstanding, gribtocdl just creates cdl
> > files with only data of the projection/lat/lon/etc.  To actually create a
> > netCDF file one has to use gribtonc with the cdl created by gribtocdl. ie
> >
> > % gribtonc -l - your.cdl your.nc < your.gribdata
> >
> > This will create a your.nc netCDF file. gribtonc also needs the ncgen
> > utility to create the template your.nc from the your.cdl. ncgen is
> > included in the netCDF package.  I wasn't quite sure of your question, let
> > me know if I misinterpreted it.
> >
> > Robb...
> >
> > >
> > > I am running the utility on a Linux machine.
> > >
> > > Any suggestions on why this is occuring?
> > >
> > > Thanks,
> > > Lori
> > >
> > >
> > >
> > > ------- 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/
> > ===============================================================================
> >
>
> --
> ----------------------------------------------------
> 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
>
>

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