[gradsusr] multiple variables in one netCDF

[Jennifer Adams]

Hi, Teddy --
The ncks -A command merges files with different variables having  
identical grids. Concatenating files with netcdf operators (i.e.,  
extending the time steps) is something different. The NCO docs  
describe how to do this, I am working on a merge of their docs to add  
to the sdfwrite docs to make it easier for GrADS users, but haven't  
finished testing it out to make sure it works. It is a bit more  
involved, since you have to change the time dimension to a 'record'  
dimension, so that it can be extended. You have to use ncecat followed  
by ncpdq followed by ncwa and then ncrcat.

I will think about how to add an option to 'sdfwrite' to set a  
dimension to be a record dimension; this will save some trouble when  
concatenating files. In the newer versions of the netcdf library you  
can have more than one record dimension.

--Jennifer





On Sep 3, 2010, at 1:17 PM, Teddy Allen wrote:

> Is this procedure similar to combining files found in NCO? Or, is it  
> only a way to combine multiple variables into one file without  
> extending the time steps?
> does this make sense?
> thanks,
> teddy
>
> http://www.teddyallen.com
>
> "To move quickly, go alone. To move far, go together."
>
> African Proverb
>
>
>
> From: Jennifer Adams <jma at cola.iges.org>
> To: GrADS Users Forum <gradsusr at gradsusr.org>
> Sent: Fri, September 3, 2010 12:59:48 PM
> Subject: Re: [gradsusr] multiple variables in one netCDF
>
> The netcdf operator 'ncks' can do this with a simple one-line command:
> ncks -h -A file1.nc file2.nc
>
> The -h option does not modify the global attribute 'history', the -A  
> options means the variables in file1 are appended to file2. There is  
> no need for me to write a whole lot of code in GrADS to do this when  
> it is so easy with ncks.
> --Jennifer
>
>
> On Sep 2, 2010, at 8:35 PM, Don.VanDyke at noaa.gov wrote:
>
>> Hello,
>>
>> Is there a way to write multiple variables to one netCDF file  
>> through GrADS instead of having to do separate files?  I've tried  
>> the obvious way of simply issuing two sdfwrite commands to the same  
>> file, but it didn't work.  The second variable just overwrote the  
>> first.  Thanks for any help given!
>>
>> Don Van Dyke
>> NWS Tallahassee, FL
>> _______________________________________________
>> gradsusr mailing list
>> gradsusr at gradsusr.org
>> http://gradsusr.org/mailman/listinfo/gradsusr
>
> --
> Jennifer M. Adams
> IGES/COLA
> 4041 Powder Mill Road, Suite 302
> Calverton, MD 20705
> jma at cola.iges.org
>
>
>
>
> _______________________________________________
> gradsusr mailing list
> gradsusr at gradsusr.org
> http://gradsusr.org/mailman/listinfo/gradsusr

--
Jennifer M. Adams
IGES/COLA
4041 Powder Mill Road, Suite 302
Calverton, MD 20705
jma at cola.iges.org



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