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Re: NCML aggregation and variableAgg

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  • Subject: Re: NCML aggregation and variableAgg
  • Date: Fri, 29 Sep 2006 11:42:09 -0600
Hi Jon,
I don't see anything in the docs or the code to suggest that there is a wildcard capability (or any other kind of shortcut) for declaring aggregation variable names. 

The docs say this about "joinNew":

   A JoinNew dataset is constructed by transferring objects
   (dimensions, attributes, groups, and variables) from the nested
   datasets in the order the nested datasets are listed. All variables
   that are listed as aggregation variables are logically concatenated
   along a new dimension, in the order of the nested datasets. A
   coordinate Variable is created for the new dimension.
   Non-aggregation variables are treated as in a Union dataset, i.e.
   skipped if one of that name already exists.
which seems to explain why you don't get any aggregation or time dimension with your wildcard example. Sounds like you might just be getting the first dataset it finds. 


Ethan

address@hidden wrote:

Hi all,

I'm creating aggregations of NetCDF files by aggregating on a new time
dimension, whose values come from the names of the files.  My .ncml file looks
like this:

<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
  <aggregation dimName="time" type="joinNew">
    <variableAgg name="ICEC"/>
    <variableAgg name="ICETK"/>
    <variableAgg name="M"/>
    <variableAgg name="...etc"/>
    <scan location="C:/data/FOAM_one/" suffix=".nc"
dateFormatMark="FOAM_#yyyyMMdd.HH" />
  </aggregation>
</netcdf>

It's a bit tedious to have to specify explicitly all the variables I want to
aggregate.  I want to aggregate all variables so I would like to be able to
have:

<netcdf xmlns="http://www.unidata.ucar.edu/namespaces/netcdf/ncml-2.2";>
  <aggregation dimName="time" type="joinNew">
    <variableAgg name="*"/>
    <scan location="C:/data/FOAM_one/" suffix=".nc"
dateFormatMark="FOAM_#yyyyMMdd.HH" />
  </aggregation>
</netcdf>

or something like that.  Is this possible?  If I try that, no variables get
aggregated (when I open a GridDataset, there is no time dimension).

Thanks in advance,
Jon


--
Ethan R. Davis                                Telephone: (303) 497-8155
Software Engineer                             Fax:       (303) 497-8690
UCAR Unidata Program Center                   E-mail:    address@hidden
P.O. Box 3000
Boulder, CO  80307-3000                       http://www.unidata.ucar.edu/
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